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Thread: 1981 BMW 320i e21 fuel regulator adjustment HELP

  1. #1
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    1981 BMW 320i e21 fuel regulator adjustment HELP

    1981 BMW 320i e21 fuel regulator adjustment, HELP

    I can not get my car started, there is gas and there is spark , but the gas is not getting thru the fuel regulator .
    My mechanic moved the fuel regulator's adjustment (hex screw) and the Air (slot screw) under the intake air manifold , and know the settings are all wrong ???

    Can someone help me on what to do ??? , how to set those two adjustment screws ????? , so it will start and get it out of that mechanic's shop .

    Remarks :
    a .- The fuel regulator was removed and the hex screw was re installed , after it went all the way down into the flap
    b .- The fuel pump was removed , because the fuel supply was not continuous and low pressure ????
    c .- Plan "B" , a service shop or repair shop for the fuel regulators ??? , near Texas
    d .- Conversion kit to carburetor ?????

    Please advice

  2. #2
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    See Faq's:
    Fuel System Troubleshooting & Tuning

    Re-Adjust Base Mixture Setting
    If you’ve done major fuel system work such as swapping fuel distributor, AFM, WUR, fixed major vacuum leaks or have a non-running car it may be a good idea to re-set your base mixture setting to correct a grossly misadjusted mixture. To do this, jumper the fuel pump. Turn the mixture screw clockwise (rich) until you hear the injectors start to spray. They will make an audible squeel/humming noise. Back off counter clockwise (lean) till they stop, then back off another 1/8 turn. This should get the mixture setting close enough for the car to at least run assuming there are no other problems.


    Randy

  3. #3
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    Thanks Randy
    Today we removed both gas tanks , and checked both pumps , which were very dirty with rust from the tanks , one strainer was missing and the metal filter was clogged , so we will replace it tomorrow and put the fuel system back together and run the test .
    Just one question : the mixture screw will start all the way from the top ???? and then
    Turn the mixture screw clockwise (rich) until you hear the injectors start to spray. They will make an audible squeal/humming noise. Back off counter clockwise (lean) till they stop, then back off another 1/8 turn. This should get the mixture setting close enough for the car to at least run assuming there are no other problems.
    We can get one injector out and run the test into a glass bottle ??????

    Please let me know

  4. #4
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    Disconnect the plastic lines from the injectors with open end wrenches-so they wont break, then pry injector with 2 screwdrivers one on each side-it will pop out-then reconnect.

    The Air/Fuel Mixture 3 mm hex screw is accessed thru the small hole behind the fuel distributor in the volume air box, I use this and have two of them-goes thru the hole in the throttle body and sits in the a/f hex screw to adjust clockwise, ect the a/f mixture. They are inexpensive, about 6 inches long.

    Eklind 54930 3 mm Cushion Grip Hex T-Key



    51PyyiXBjmL._SL1200_.jpg


    Randy
    Last edited by 320iAman; 07-04-2017 at 09:58 AM.

  5. #5
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    Randy
    I do have the hex screw and have located the point of adjustment , and I think that tomorrow , the gas tanks will be re installed and with gas so we can try to get it going as you suggested , I will let you know if I can get it running (I sure hope so !!!!)

  6. #6
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    Its a slight adjustment once its running ccw or cw to dial it in, remove the tool after each adjustment and rev the motor-check its idle speed, while it is being adjusted, the tool in the hole will restrict the air/fuel arm-not what you want.

    Once the Motor is running on its own, Luis, Now-tell your mechanic or diy and do exactly what I am going write here and the Air / Fuel mixture will be precisely adjusted to perfection. Disconnect the O2 sensor wire-the small black one with the female terminal and connect the plus lead of a very good multimeter-capable of reading 1V and less to it- the point of the multi lead pushed into the female terminal of the O2 sensor wire and ground the black wire of the multimeter to the chassis of the car, now adjust the a/f with the hex tool and watch the reading on the multimeter, adjust ccw or cw until the voltage reading is near +.8V, it will bounce around from .6V to .85V + mostly around .8V+ keep adjusting till its about +.825V maximum, this sets air/fuel in the power band area of air/fuel mixture, the best setting for all starting and running conditions, I try and aim at .812V+, the reading will steady sometimes and this is good enough, low +.800V maximum bounce upward is perfect.

    This is in FAQ's, except this is more precise, forget .45 stuff-thats adjusting using the Frequency Valve, + .8V uses the O2 sensor and set a/f mix in the power band area, the ultimate setting for your ultimate driving machine-BMW.

    I set mine like this and smog it ect works perfectly, the computer works best in adjusting a/f as well when O2 sensor wire is reading around +.8V as well. mine adjusts constantly- FMV buzzes frequently using these settings of A/F as it should.

    Pull the tool after each slight adjustment and read the O2 sensor voltage, let the reading settle down, then keep adjusting till power band area +.812-.825 is maximum on bounce.. your in like flint- its precise work.

    Randy

    Off topic-I just picked up apair of Adidas Boost ESM running shoes(made in germany),these are voted as the best running shoes the last 3 years on the market by serious runners-initial cost $160--now less,,I'm running again 5 times a week to stay in shape and keep my weight down where it should be
    Last edited by 320iAman; 07-07-2017 at 11:17 AM.

  7. #7
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    Hello Randy
    I had to take care of some other issues , such as , cleaning both gas tanks and repair them , clean both pumps , get a new gas filter and strainer , and on and on...... , but yesterday we started the old 320i and this is the way it went (I need help !!!!)
    a .- Hard start , it takes about 5 to 10 sec.(every time)
    b .- Runs rough to semi smooth , for about 15 sec and stops , at any speed, 1000 , 1500 or 2000 RPM , and did it many times ,more than 15 .
    c .- Before it stops I heard a "click" some were within the engine compartment .
    d .- I do not understand what is happening or what to do so we stop working on it for know .

    CAN YOU HELP ME SOLVE THIS PROBLEM ???? , or what to do ???? , I do not know were to start troubleshooting

    If you have any questions , please let me know !!

    Luis


  8. #8
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    Randy or any body
    Today , We continued troubleshooting the above mentioned problem :
    a .-Hard start , it takes about 5 to 10 sec.(every time)
    b .- Runs rough to semi smooth , for about 15 sec and stops , at any speed, 1000 , 1500 or 2000 RPM , and did it many times ,more than 15 .
    c .- Before it stops I heard a "click" some were within the engine compartment .
    d .- I do not understand what is happening or what to do so we stop working on it for know .

    Also , we checked all electrical connections , above the engine , blue with blue , brown with brown , black with black , etc.... , there is a sensor ?? in the front part of the engine (it was damaged and repair) do not know the usage of it ??? ,

    We tried again , with the same results , hard start , runs rough between 10 to 15 sec and shuts down ??? , but , there were no "clicks" this time in the engine compartment , also we noticed when the ignition switch is activated the pumps will not start , it takes about 5 to 10 sec. and both will start .
    Remarks : the fuel check valve was inspected and it looks OK , all fuel lines were checked and no leaks were detected .

    Please advice



  9. #9
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    What is the fuel pump pressure with gauge connected to the fuel distributor ?
    The fuel pumps run only when they receive a pulse from the coil--engine is running or jumpered.

    You test the fuel pumps by removing the fuel pump relay then place a jumper wire between 87 and 30, this by passes the fuel pump relay and the fuel pumps will run-constantly,,then you can listen to each fuel pump and hear if they are both working, can also hook up a fuel pump tester and see if you get 60-70 psi fuel pump pressure to test fuel pumps, with the fuel pump socket jumpered you can start the car and rev it up and drive it,,, remember the fuel pumps will be on as soon as the key is turned on and will not stop when the motor shuts off..key controlled.

    It could be the fuel pump relay is bad-that is shorts out when heated up.

    Clicking noise could be relay or the frequency modulation valve sounding off,,check if the car runs with the fuel pump socket jumpered, start it up and wait.

    Pull the fuel pump relay and jumper the socket as shown with jumper wire shown below.

    Fuel Pump Relay Jumper.jpg

    Post the result of the Fuel pump socket jumpered-key on-indicator lights glowing-fuel pumps running and starting and running the car, with jumper installed and key on(motor not running) the fuel circulates thru the fuel system-yet none is delivered to the fuel injectors until you lift the plate in the volume air box.

    The jumper wire has two male terminals crimped on - wire size- AWG 14,16 or so

    Here is what the jumper wire looks like two versions one with 8 amp fuse other straight wire: I have used both , they work fine.

    DSCI0009t.jpg

    Randy
    Last edited by 320iAman; 07-20-2017 at 01:05 AM.

  10. #10
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    Bump

    Randy

  11. #11
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    What is the fuel pump pressure with gauge connected to the fuel distributor ?
    We do not have a fuel pressure gauge , how ever , the sprayed gas coming out of the injector looks as fine mist with pressure , when pumps are on. We will use a pressure gauge today .
    The fuel pumps run only when they receive a pulse from the coil--engine is running or jumpered.
    Correct !!
    You test the fuel pumps by removing the fuel pump relay then place a jumper wire between 87 and 30, this by passes the fuel pump relay and the fuel pumps will run-constantly,,then you can listen to each fuel pump and hear if they are both working, can also hook up a fuel pump tester and see if you get 60-70 psi fuel pump pressure to test fuel pumps, with the fuel pump socket jumpered you can start the car and rev it up and drive it,,, remember the fuel pumps will be on as soon as the key is turned on and will not stop when the motor shuts off..key controlled.Today , we will jump the fuel pump relay as indicated by you , and test it and buy a new one
    We have those jumpers , thanks
    I will report back to you , tonight and I hope we can fix this problem . Thanks


  12. #12
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    Quote Originally Posted by luis320i View Post
    What is the fuel pump pressure with gauge connected to the fuel distributor ?
    We do not have a fuel pressure gauge , how ever , the sprayed gas coming out of the injector looks as fine mist with pressure , when pumps are on. We will use a pressure gauge today .
    The fuel pumps run only when they receive a pulse from the coil--engine is running or jumpered.
    Correct !!
    You test the fuel pumps by removing the fuel pump relay then place a jumper wire between 87 and 30, this by passes the fuel pump relay and the fuel pumps will run-constantly,,then you can listen to each fuel pump and hear if they are both working, can also hook up a fuel pump tester and see if you get 60-70 psi fuel pump pressure to test fuel pumps, with the fuel pump socket jumpered you can start the car and rev it up and drive it,,, remember the fuel pumps will be on as soon as the key is turned on and will not stop when the motor shuts off..key controlled.Today , we will jump the fuel pump relay as indicated by you , and test it and buy a new one
    We have those jumpers , thanks
    I will report back to you , tonight and I hope we can fix this problem . Thanks

    This is where you connect the fuel pressure gauge to get a read on your fuel pumps that they are working properly, more specifically the main or exterior fuel pump, on top of the fuel distributor-one line going to the Warm up Regulator is disconnected and the fuel pump gauge is connected there instead, jumper the fuel pump relay socket, key on and pressure will build from the exterior fuel pump pressurizing the fuel system.

    This is a good way to run fuel system cleaners before startup, prime the fuel supply, check for leaks,test fuel distributor output to each injector, ect.

    Randy
    Last edited by 320iAman; 07-20-2017 at 11:09 AM.

  13. #13
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    Thanks for your advice , but today the mechanic did not went to the warehouse , so we will continue sometime next week , and I hope that we can get it right and running good , so I can drive and enjoy my 320i .
    Have a good week end

  14. #14
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    Quote Originally Posted by luis320i View Post
    What is the fuel pump pressure with gauge connected to the fuel distributor ?
    We do not have a fuel pressure gauge , how ever , the sprayed gas coming out of the injector looks as fine mist with pressure , when pumps are on. We will use a pressure gauge today .
    In case you, or the mechanic are not aware:

    The injectors are NOT suppose to spray or leak any fuel unless the meter-plate in the 'air flow meter' is raised. The meter-plate raises when the engine is running and air is passing through it. The meter-plate can also be carefully raised by hand to test the injectors spray patterns.

    1) ! If the 3mm 'idle fuel mixture' screw is turned too much in the clock-wise direction, fuel will leak or spray out of the injectors.

    2) ! If the fuel meter piston/plunger is stuck in the open, or partial open position, fuel will leak or spray out of the injectors.

    3) ! If there is a problem inside the fuel distributor, fuel will leak or spray out of the injectors.

    Do NOT flood/drown the engine with fuel when testing the fuel system.
    Tbd

  15. #15
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    I am trying to understand your comments , so I can check if I am doing it right ,
    The injectors are NOT suppose to spray or leak any fuel unless the meter-plate in the 'air flow meter' is raised.
    How do I know if is raised ????
    The meter-plate raises when the engine is running and air is passing through it. The meter-plate can also be carefully raised by hand to test the injectors spray patterns.
    I am not able to keep the engine running , only about 15 sec
    How can I carefully raise by hand ?????

    1) ! If the 3mm 'idle fuel mixture' screw is turned too much in the clock-wise direction, fuel will leak or spray out of the injectors. Please elaborate, ????

    2) ! If the fuel meter piston/plunger is stuck in the open, or partial open position, fuel will leak or spray out of the injectors.Please elaborate, ????

    3) ! If there is a problem inside the fuel distributor, fuel will leak or spray out of the injectors.Please elaborate, ????

    Do NOT flood/drown the engine with fuel when testing the fuel system.
    Remarks:
    Still very hard to start , and runs for about 15 sec and stops

    Please advise , and thank you for your help . I hope I can get it to run and get it back to my house


  16. #16
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    Quote Originally Posted by luis320i View Post
    I am trying to understand your comments , so I can check if I am doing it right ,
    The injectors are NOT suppose to spray or leak any fuel unless the meter-plate in the 'air flow meter' is raised.
    How do I know if is raised ????
    The meter-plate raises when the engine is running and air is passing through it. The meter-plate can also be carefully raised by hand to test the injectors spray patterns.
    I am not able to keep the engine running , only about 15 sec
    How can I carefully raise by hand ?????

    1) ! If the 3mm 'idle fuel mixture' screw is turned too much in the clock-wise direction, fuel will leak or spray out of the injectors. Please elaborate, ????

    2) ! If the fuel meter piston/plunger is stuck in the open, or partial open position, fuel will leak or spray out of the injectors.Please elaborate, ????

    3) ! If there is a problem inside the fuel distributor, fuel will leak or spray out of the injectors.Please elaborate, ????

    Do NOT flood/drown the engine with fuel when testing the fuel system.
    Remarks:
    Still very hard to start , and runs for about 15 sec and stops

    Please advise , and thank you for your help . I hope I can get it to run and get it back to my house
    1.) Yes it will lift the fuel distributor plunger and send fuel to the fuel injectors when its clockwise enough.{ also can send fuel to the fuel injectors and test spray pattern(with each injector removed and in a jar) and with them taken off the fuel line- for volume of fuel test-timed to adjust each line to the fuel injectors by lifting the air plate by hand or a magnet if the big air boot is taken off, you can lift the plate by hand or other carefully thru the circular hole where cleaned air goes thru remove the air cleaner box and the rubber hose} .

    from FAQ's

    Re-Adjust Base Mixture Setting
    If you’ve done major fuel system work such as swapping fuel distributor, AFM, WUR, fixed major vacuum leaks or have a non-running car it may be a good idea to re-set your base mixture setting to correct a grossly misadjusted mixture. To do this, jumper the fuel pump. Turn the mixture screw clockwise (rich) until you hear the injectors start to spray. They will make an audible squeel/humming noise. Back off counter clockwise (lean) till they stop, then back off another 1/8 turn. This should get the mixture setting close enough for the car to at least run assuming there are no other problems.

    2.)* It could if the plunger is stuck, simply remove the the three screws( after disconnect of all the fuel line on the Fuel distributor)holding the Fuel distributor to the volume air box and lift---CAREFULLY--put your hand down there as the plunger may not have a plunger catch-the plunger may fall out---and the little spring thats on top of the plunger may fall out as well, if the plunger moves easy in the bore its not stuck with or without the plunger catch on the bottom--mine does not have a plunger catch--so careful is done handling it.

    3.) It depends on what problems it could have, example if the the o-ring 1st-smallest one on the fuel regulator piston is missing or too flat-fuel pressure could be so low that it would not open the injectors which require 44 psi to open them up as they are spring loaded-only-mechanical injectors and the fuel would return to the tank and not go thru the fuel distributor to the fuel injectors. The fuel regulator piston is accessed thru the front of the Fuel Distributor and removed by 16 mm socket I believe--I'd change out both O-Rings the Pressure regulator and The Warm Up Regulator O-ring, later.

    What you need to do is buy a Bosch CIS tester, this will test parts of the Fuel distributor, fuel pressure at the Fuel distributor and the warm up regulator which is the heart of the Bosch CIS.

    *Since the car runs for 15 seconds--fuel is getting thru to the fuel injectors from the fuel distributor.


    __________________________________________________ ________________________________________

    Important Questions: Answer these before any adjustments **..

    When you start the car cold what idle speed in rpms is showing?

    What rpms are showing when the car stops running?

    When you step on the gas when the car is running does it rev up much or very little-sluggish to rev up--very slow ?

    __________________________________________________ __________________






    Randy
    Last edited by 320iAman; 08-01-2017 at 01:55 AM.

  17. #17
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    Are these the symptoms ?
    Hard Starting ?
    When gas pedal is applied and put in gear there is no or very low power to drive the car ?
    The idle is low when warming up ?
    Is the air auxiliary valve open ?

    If the answer is yes to all of these is not the Fuel Distributor its the Warm up Regulator(Control Pressure Regulator)

    When the car starts up the warm up regulator pressure is around 20 psi, allowing more fuel per air volume with air auxiliary valve open Idle should be 1200 to 1500 rpms, then as current flows thru the WUR it increases pressure and starts to push down the plunger in the fuel distributor and at the same time the Air auxiliary valve is closing--net effect the idle will drop down from 1200 to 1500 rpms and when warm be at 850 rpms plus/minus 50 rpms--standard current idle speed-this whole thing is called warm up circuit.

    The Wur is at ~ 20 psi on cold startup and then increases to around 46-50 psi, this provides full power to the motor, if the WUR is stuck above 20 psi--this will cause hard starting, very low power and motor shutoff--the wur can be tested by a CIS testing equipment.

    Toolaid 33380

    C.I.S. K-Jetronic Fuel Injection Tester


    • Test C.I.S. (Continuous Injection System) found on European cars and Volkswagen models assembled in the U.S. equipped with the Bosch C.I.S. K-Jetronic Fuel Injection Systems.
    • This in-line pressure tester indicates problem sources - control pressure regulator, fuel distributors or other specific fuel injection components that may require replacing.
    • Tests C.I.S. Non-Electronic with metric threads, C.I.S./Lambda Electronic with metric threads and C.I.S. E-Electronic with metric threads (Will not test other Bosch fuel injection systems. To test non-Bosch fuel injection systems, use our Cat. Nos. 36200, 36250, 38000, 56200, 56250 & 58000).
    • Gage with hang-up hook measures 2 1/2" diameter and has dual scale: 100 PSI and 7 BAR.
    • Supplied in a clear pouch with all adapters, adapter application chart, hook-up and parts schematic drawing and complete instructions.





    33800.jpg



    Testing the WUR will further isolate and help solve the issue, no need to adjust anything, however as a rule of thumb-here it is--when diagnosing a running problem with any car-the car should have all new tune up parts-spark plug,rotor, air cleaner and so forth, valve should be adjusted and timing set correctly- if this can be done.

    The WUR can be rebuild by Bob White at Fuel Injection Corporation or Larry at CIS Flow Tech, they put in all new parts including the heating coil, they also rebuild Fuel Distributors-these guys educate ASE Certified Mechanics and Factory Trained Mechanics on what they rebuild and do, including install. Bob White can rebuild the ECU as well, he reset mine and rebuilt the WUR ,working as it should.

    http://www.fuelinjectioncorp.com/

    http://www.cisflowtech.com/

    You are welcome

    Randy

    Quote of the day:

    Every man marches to the sound of his own drummer.
    Last edited by 320iAman; 08-02-2017 at 11:33 AM.

  18. #18
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    Randy
    Previous work done , before this latest problem .
    1 .- Both fuel tanks removed , cleaned , welding repairs , new pump's strainer , new fuel filter , blew air from the fuel regulator to the fuel tanks , new gaskets , etc.... , we thought everything was cleaned .
    2 . - Same problem persisted , hard start , run for about 15 sec and shuts down , over and over .......?????
    3 .- I got new help , and suggested we use propane gas feed (low pressure & just for testing) , the engine started and ran very well for long time !!!!!
    4 .- Remove both fuel tanks again and inspect them , we found a lot of rust and settlement , Why ??? I don not know ??? , the tanks' walls are very rusty and falling a part , not good , so the only answer is to replace them . I checked on the internet and the set is over 1000.o usd , not good .
    5 .- I got a used poly fuel tank , that we re going to install it (next week) in the trunk against the back seat , and adapt all hoses , pump strainer , etc.... and do it safely , run some test and see if it works Ok .
    6 .- Once we get the engine running , we will apply all of your recommendations and suggestions in order to get it right and , finish other issues that I want to get the right .
    I will keep you posted , and if you have any questions or suggestions , please let me know . Thanks again for you help

    Luis 320i

  19. #19
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    Randy or anyone that can help
    Both gas tanks are removed (out) and a "new" poly gas tank is in place , with gas pump , and level sending unit (new wiring in place) , and , gas .
    I re started yesterday , after filling the new gas lines for the first time , my old 320 i started (rough) and ran for about 90 sec and stop by it self .
    Re started and ran better , and I made small adjustment to the air screw and ran Ok. AND , STOPPED again . And did it several times , and every time ran for a shorter period of time
    I ordered a new fuel pump relay , mine looks bad , and the contact looks bad , so hopefully this will help solve my problem when I get it and install it this week .
    However , the TACH , stopped working , and I do not understand why ??? , so I do not know the actual RPMs.
    Can someone help me trouble shoot my TACH problem ????

  20. #20
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    I had a problem once a really tough one and I figured it out.The car would run and no problems then for some reason it would stop, I checked everything and it was good. I wiggled a relay and the car started, I knew then that a soldering connection in the relay/ fuse box was the problem,,at this point I was having my car worked on in auto electrician shop, he came out and said he could not find it, then went back and found the soldering to a wire on a relay socket was cracked-not tight and as it heated from use,it would drive the resistance up and shut off the car, in series with the ignition switch ,if it was parallel wiring to the ignition switch it would not effect yet in series does. To get an idea of this,,wall sockets, one wire goes off it takes out all wall sockets connected to it as they are wired in series and not parallel .

    After the solder repair, problem gone..

    I would loosen the fuse box and check or re-solder all the connections so that they are tight.. I now do my own work,,lol. Solder connections do not last forever, a good tight connection relay/fuse box with good wires is essential and should not be overlooked.

    In your case it sounds like a fuel system problem, each device,fuel lines and the wiring needs to be checked and okayed to get to the source of the problem.

    The Tachometer gets it input from the ignition coil pulses,there is quite a few devices connected in line going to the tachometer, the Speed Relay, Ignition Chip, Fuel Pump Relay and then the Tachometer.
    See if new Fuel pump relay gets it working again.



    Randy
    Last edited by 320iAman; 09-06-2017 at 10:36 AM.

  21. #21
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    Hi Randy
    Thanks for your help , and I agree with you , my electric/mechanics are not doing a good job , I have been trying to do it my self , but it is a learning experience , and takes time and some frustration but I think I am making some progress . I am going to try to explain what I did today and see if I make sense , and I need your comments and help .
    I got my new fuel pump relay and went to the warehouse and install it , tried to start my 320i with no luck !.
    I then install the old one , and it started rough (as always) and ran for few seconds (30 sec) and stop .
    Checked the new relay #s (87, 15 , 31 , 1) vs old relay #s (87 , 15 , 31 , 31b )and we can see the difference , so I believe I got the wrong relay for my application . The I returned later during the day and I could not find the wright one .
    Tried again with the old relay , and had a guy hold the contact closed and the engine started and ran for longer period of time , stopped by it self , re started and repeat this several times. When this guy let loose the contact , it opened and the engine stopped .
    The relay # is SK 6460 , with 3 standard pins and one skinny pin .
    Also , behind the relay box , couple of connections feel loose , not thigh , so tomorrow I will try to fix them and try again .
    I think the relay is not holding the contact closed , so I will try to do it manually and see what happens , but I need to fin this new fuel pump relay , any ideas where ????
    Please advise

  22. #22
    Join Date
    Nov 2007
    Location
    Sacramento, California
    Posts
    4,704
    My Cars
    1980 BMW 320i E21 M10B18

    Cool

    KAE 3.304.100 , BMW # 12631277245, $22.74/free shipping, KAE has been used for some time now..BMW: 320i 1977-83 and others. I use this one.

    s-l1600a.jpgs-l1600b.jpg

    http://www.ebay.com/itm/NEW-KAE-Fuel...RZgD9h&vxp=mtr

    Randy
    Last edited by 320iAman; 09-06-2017 at 11:30 PM.

  23. #23
    Join Date
    Dec 2014
    Location
    Brownsville , Texas
    Posts
    137
    My Cars
    1981 BMW 320i
    Randy
    Thanks for your info.
    I just want to say , this picture shows the pin numbers (31 , 15 , 87 & 1) , and these #s are the same as the new relay that I used today and did not work in my car ?????, I just have this concern .
    Also the old relay big white #s are 1363827.2 , 12 v max / 20 amp , and the one shown in this pic is 3.304.100 , 12 v max / 30 amp
    If this relay that you are indicating works , I will buy it and try it
    Please reply
    Thanks


  24. #24
    Join Date
    Nov 2007
    Location
    Sacramento, California
    Posts
    4,704
    My Cars
    1980 BMW 320i E21 M10B18

    Cool

    This is the correct relay and 12V/30 amp with the pin configuration as shown and is Correct per BMW specifications, with only 20 amps the fuel pump relay you have would be taxed plenty-too much,this relay-Fuel Pump Relay- provides power to 2 fuel pumps, the warm up regulator and air auxiliary valve and signal voltage to the Main or Lambda Relay.

    From realoem no 3 in diagram of parts

    https://www.realoem.com/bmw/enUS/showparts?id=1733-USA-01-1980-E21-BMW-320i&diagId=61_0577

    Part Number:12631277245, KAE part number interchange is 3304100 for BMW 12631277245

    https://www.realoem.com/bmw/enUS/par...&q=12631277245

    Part 12631277245 was found on the following vehicles:



    Its the right part, buy it...

    Randy
    Last edited by 320iAman; 09-07-2017 at 11:17 AM.

  25. #25
    Join Date
    Feb 2009
    Location
    District Nine
    Posts
    17,984
    My Cars
    sold 78 BMW 320i
    Glad you're on top of this, Randy. Lots of great info. I did not realize there's two different amp ratings available for the e21 fuel pump relays. Maybe this is related to the many pump relay failures on e21s equipped with two fuel pumps and the lambda system. My '78 only has one fuel pump, no Lambda - and both my oe '78 pump relays (one as spare) are rated at 20 amps; both still work
    Tbd

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