Oh yes ... I should have mentioned that the hole is usually plugged with a bit of epoxy or something.
The one in the pic (dated 7/80) came off a parts car someone had a couple of years ago. When I got it it was pretty grotty and during the cleanup I noticed it was a bit lose. I was pretty sure it was covering a calibration screw and I pried it out to check. If I ever have to use it, it will get a blob of neutral cure silicon in there to seal it back up.
Sure .. if the plug is missing then there is probably a good chance someone has been messing with it. After 30 odd years as an engineer, I'm no longer amazed by the strange things some people do to stuff they have no real idea about how it works or what they are doing.
Having said that .. I should remind anyone reading this .. that this is a nothing to lose situation ... it's not working, so testing it at a lower temperature to see if there is any improvement before trying to adjust it (which may or may not fix the problem) is worth doing.
Randomly adjusting a TTS in the hope it will improve things ... nope.
I have been having a think about possible ways to bench test the TTS .. but to test it across the range of its' operating temperatures would be time consuming and pretty tedious as far as I can see?
Bit more thinking to do on that.
Cheers
Last edited by GDAus; 06-11-2019 at 06:35 AM.
hmm .. Wonder what happens if I do this ...
Wow, thanks!
i hadn't check back for a few days and for some reason I don't get notified that there was a post so sorry.
When I said "to frame" in my tests it was to the frame in the engine bay. A big bolt head that was sanded down to bare metal on a frame rail, if that makes a difference?
I have been wondering if maybe I was wrong in calling it a goner, so I have been doing more tests.
i been doing a lot of reading on the TTS and the cold start system and found a test proceedure in an old shop manual that was in the trunk when I bought the 320. It said the following to test the TTS:
"Take a test light and connect the W terminal to the + pos battery below 35C and it should light up. Then do the same when the temperature is above 35C and the it should not light up."
i did the tests and the light lite up on both cold and hot tests, the car was not running durning the tests.
Last edited by msiert; 06-14-2019 at 11:11 PM.
Murray
I saw that hole on mine too. It look like a black dot so thinking it still has the plug, I look closure at it tomorrow. It be worth a try to adjust it!
i did order a new TTS but if mine is good I'll put the new one on the shelf next to the other parts that I have order and never installed.
Murray
The "W to frame" is W to the body/housing of the tts! not the car's body/frame
(there may be 'some ohm resistance' from W to the car's chassis if some bad ground somewher's)
Example: tts 'frame' is where the time/temp numbers are stamped on the tts (the HEX on the tts).
Last edited by epmedia; 06-15-2019 at 06:43 AM.
Tbd
Hi ...
Yes that is a perfectly valid test ... also unplugging the connector on the Cold Start Injector (CSI) and using a test light across the terminals in the plug and try to start the engine will also test the TTS and the associated wiring to the CSI. The light should come on below 35c and the go out if the engine is cranked long enough for the appropriate temperature.
Also ... as epmedia has pointed out, there is a good chance the "extra" 30 ohms you got when you tested the TTS originally is likely a false reading. If you want to make resistance measurements on a car ..it's a good idea to disconnect the battery first. The engine/chassis are all part of one big electrical circuit and with the battery connected, it's possible to find 2 points with some sort of Potential Difference (ie voltage) between them that can "fool" a multimeter into giving a false reading.epmediaThe "W to frame" is W to the body/housing of the tts! not the car's body/frame
(there may be 'some ohm resistance' from W to the car's chassis if some bad ground somewher's)
Example: tts 'frame' is where the time/temp numbers are stamped on the tts (the HEX on the tts).
I have been doing some followup and did a simple circuit to bench test the TTS. I ran some calibration tests that seem to work nicely. Unfortunately I've had to work all weekend and I don't have the time to write it up yet.
I'll probably do a new thread on the testing and calibration because there are a few nuances in the way the circuits work in different models around the world.
Cheers
hmm .. Wonder what happens if I do this ...
Ok, the test was done over with the frame being the housing of the TTS.
Terminal G and Ground to TTS brass base:
below 30 C.........38.8 ohm......acceptable range 25 to 40 ohm
above 40 C.........75.2 ohm......acceptable range 50 to 80 ohm
Terminal W and Ground to TTS brass base:
below 30 C.........3.5 ohm........acceptable range 0 ohm
above 40 C.........147.1 ohm.....acceptable range 100 to 160 ohm
Terminal G to Terminal W
below 30 C.........38.5 ohm.......acceptable range 25 to 40 ohm
above 40 C.........72.2 ohm.......acceptable range 50 to 80 ohm
Other then not having 0 ohm on the W to ground (cold) its good, is the 3.5 ohm (cold) close enough to call my TTS good?
EDIT: Forgot I still failed the test light going off when it above 35 C ???
Last edited by msiert; 06-15-2019 at 12:00 PM.
Murray
i did the "hot start part" of the cold start injector test......with my TTS bypass hooked up it lite up the light when the starter was cranking.
With the TTS stock terminals hooked back up, during cranking the lights did not come on, as should they not
I'm waiting for the engine to get cold to finish the test.
Thanks for the pointer!
Update:
With a cold engine and the cold start injector plug hooked up to the test light, it lite up on cranking with the TTS stock terminal hooked up.
Looks like the TTS is working as it should.
Last edited by msiert; 06-15-2019 at 07:43 PM.
Murray
This 3.5 ohm has me curios, I would hope for it to be closer to 0 ohm.
Terminal W and Ground to TTS brass base:
below 30 C.........3.5 ohm........acceptable range 0 ohm
above 40 C.........147.1 ohm.....acceptable range 100 to 160 ohm
----
What does your meter read when you connect the two meter leads together?
for example, my meter test leads read 0.2 ohms resistance. (I have not calibrated the meter yet)
-----
not sure about your test light tests...
Last edited by epmedia; 06-15-2019 at 07:53 PM.
Tbd
Well .. in the world of digital multimeters there's cheap, dirt cheap and kid's toys. But even a $10 one can be useful if you know it's limitations. When a multimeter is one of your main tools of your trade, the test leads are regarded as "consumables" as they suffer a lot of wear and tear. So having 1.5 Ω is a bit high, but I've had leads get up to over 3 Ωs for a single lead. Which is why I always carry a spare set out in the field.
As for calibration, unless you have access to precision voltage, current, resistance standards ... don't worry about it. Most mid to low range meters have to be pulled apart to get to the calibration settings. Something that you can check and clean, are the plugs and sockets for the leads ... if you leave them plugged in all the time with the leads wrapped around the meter (like most people) it can trap moisture and cause a bit of oxidation and bad contacts. The leads have a lot of very fine wire strands to give the leads flexibility but they can get damaged and break which pushes up the overall lead resistance.
Also, how good is the internal battery ? .. cheaper meters often can give wrong readings as the internal battery voltage drops.
After all that, when measuring low range ohms ... just short the probe tips together the get the lead resistance and subtract that from whatever the reading you get when you test.
Now .. back to the TTS issue.
If for a moment we assume your multimeter is in tip top condition and you r leads do have 1.5 Ωs of resistance .. it means your W to case resistance is 2 Ωs. That is a lot more reasonable.
Reading you latest posts .. I was wondering what temperature your TTS was at for those last tests.
One of the problems with Bi-Metallic type switches is that they open comparatively slowly. Electric switches are usually designed to snap open as fast as possible to minimise arcing as the current flow is interrupted. This means that the switch contacts are held together with a set amount of pressure until the switch opens. However, with a Bi-Met. switch, as the temperature increases, the Bi-Met. part slowly deforms as the temperature rises and reduces the pressure keeping the contacts together. During the zone of reduced pressure it is possible for the resistance across the contacts to rise above zero. So I've wondered if yours was enough out of adjustment for you to be getting a couple of ohms of resistance W to case.
Finally found some time to cobble together a test/calibration circuit and I got curious to see what sort of contact resistance occurs during slow external heating.
So hooked up my daily multimeter to read the W to case resistance and stuck the TTS into a warm water bath and let it hot soak at 30◦ C for 20 minutes - it stayed at 0 Ω.
Then started adding boiling water to the water bath. I did monitor the temperature of the bath but since this wouldn't accurately reflect the temperature of the Bi-Metal strip inside the TTS, I felt this was a bit irrelevant.
As the temperature climbed, the W-Case temp started jumping up -
0.2, 0.46, 0.89, 1.2, 1.7 ..... after that I stopped adding boiling water and it stabilised at 3.9 Ω. After about 5 minutes I started adding water again and the W - Case resistance finally reached 7.6 Ω before jumping to 143.6 Ω ... ie switch fully open.
So from a static testing point of view, it is possible to get a low ohms reading for the W - Case test at around the stated + 35◦ C and still have the TTS work properly.
You could try removing the TTS and sticking it in an ice water slushie ... let it cold soak for 20 to 30 minutes and then check the W to Case resistance and see if it will read 0 Ω. If it does, then a bit of recalibration may be all it needs.
Just have to find time to take some photos and I will post some info on testing/calibration soon.
Cheers
hmm .. Wonder what happens if I do this ...
I believe I have fixed the problem.
My existing TTS was working pretty well but was not consistent, sometimes it would start fine others it didn't. I do think the different outside temps causes it to function differently?
I installed a new TTS (the taller version) and it solve part of the problem but still had what seem as a fuel rail that wasn't fully pressurized, in that it stubbed a little till pressure was up right after starting.
I found a tread that I believe had most of the same people in this thread that went into the fuel relay and how to test it.
The thread showed a method to hook up a fan for load and had a diagram of how to hook it up to th fuel relay to test it.
Ended up cleaning my 16 amp fuse contact and replacing the fuel/choke fuse and putting in a spare fuel relay that match the one in the picture in that thread.
There was a guy in the thread that said he just blips the starter to build pressure in the rail, that I tried and it work so I have a fall back option if the problem starts up again.
Last edited by msiert; 06-22-2019 at 03:28 AM.
Murray
I have been meaning to buy a better multi meter, looked at them yesterday at an auto parts store and I could buy a new one just like mine for $34 or one with more stuff on it for $59.
Thought I would look on line to see what they have. Do you have any recommendations?
Last edited by msiert; 06-22-2019 at 03:24 AM.
Murray
Aye. blip the starter motor before trying to start the engine (if you don't hear the fuel pumps running for 1-2 seconds on the first blip, blip it again).
Is this the fp relay thread you refer too?
https://www.bimmerforums.com/forum/s...uel-Pump-Relay
Tbd
Yes it is, great thread, thanks for starting it!
Thank you for the tip on the blipping too!
That's kinda strange that the pump doesn't run 1-2 seconds in the run position? Must not be a way to setup it either, or you would have done it by now?
Last edited by msiert; 06-22-2019 at 11:38 AM.
Murray
In my testing the cold temp was 76F and the hot temp was 170F.
The outside temps around here have been in the 60's for lows and the mid 70's to maybe the mid 80's for highs during all my testing. I had the problem of hard cold starts in that complete temp range of 60F to 80F).
Did not have the cold start problem in the colder weather, winter and spring weather (20F to 50F).
Thanks for the great info on meters, I deserve a better one to learn with.I saved the old TTS to run some tests on it.
I'm finding the cold start design on this car fun to learn. I have a lot to learn but I can say this: I know more about the cold start system in a 83 BMW then I ever did before, which wasn't much.
Last edited by msiert; 06-22-2019 at 03:56 PM.
Murray
I never tried to find a solution after determining that the 'trigger' for the pump relay's IC chip only had to detect that the ignition system had sparked once. That's all it takes to get the pump(s) running on their 1-2 second run mode.
*in that thread I posted, in the relay picture, you'll see the mention of how sensitive the 'trigger' is.
Side note: With a strong battery/starting system, and strong fuel delivery - probably would not rely on those 'blips'
Last edited by epmedia; 06-23-2019 at 05:41 AM.
Tbd
First thing I'm going to do is change the fuel filter and while down there test the fuel pressure of the main pump.
The current fuel filter has almost 30,000 miles and 7 yrs on it, ordered a new one last night.
All the fuel hoses at the pump / filter location where changed out when the accumulator and intank pump was replaced back in June 2012
Murray
Wow, that's an old filter. When I replace fuel filters, I like to drain the 'inlet' into a clean white/clear container (ie: plastic milk jug) and inspect the debris - this gives an idea on the fuel tank(s) condition. There are also times that I'll drain the 'outlet' into a clean container if I suspect the filter element has torn.
Last edited by epmedia; 06-23-2019 at 09:04 PM.
Tbd
Thank you!
I was searching for the interval that the fuel filters needed to be changed for the 83. Should have gotten off the couch to grab the owner's manual but didn't want to get up
AllI could find was 2 years or 30,000 miles for the older models BMW's. The newer the model the longer the interval was, like 60,000 miles, 100,000 miles or they never need to be change.
Been reading up on how to do it and ran across the post that had the tip to drain the inlet side of the filter in a clean bucket (might as well drain the outlet side too, like you said), the post showed a picture of the rust dust in a white bucket too. Last check 7 years ago the tank looked good, hope it's the same this time!
Good thing I did the reading tonight, found out about the crush washers that need to be replaced, so those are ordered now and to make the shipping worth it, I added new rubber brake and clutch peddle pads.
Last edited by msiert; 06-23-2019 at 10:06 PM.
Murray
Glad you've already checked the tank(s). Mine are rusty dusty (I've still not treated them!). I'ts been on non-op for a few years. ugg.
Probably these pics you may have seen. Weird what the imagination can do with some pictures. lol
click to enlarge...
(this pic is not edited)
dirty-fuel-filter.jpg
dirty-fuel-filter2.jpg
dirty-fuel-filter2a.jpg
Last edited by epmedia; 06-24-2019 at 01:56 AM.
Tbd
LOL, kinda does look like a beast!
Murray
Chris Kristofferson running from a beast. lol
Tbd
The blip technique works well I have to sometimes do it 3 times then I hear the pumps run and it kicks over. Its better than starting fluid.
Sometimes when I blip the starter I get too much fuel pumped in the cylinders and get a cloud of un burnt gas at the start up. The idle stills swoops down a little once and sometimes twice even with the blipping.
If I don't blip, the idle swoops down almost to stalling once then swoops 1/2 that amount all the while whitish smoke is pouring out of the exhaust pipe.
So the blipping is the better option for now!
Waiting on the new filter to come in before testing the main pump pressure.
Going to have to wait till next week, my son is using the Bimmer as his get away car at his wedding this Friday and I want to take my time replacing the filter and if the pump doesn't test out good I would wait till a new pump comes in to do the filter and pump at the same time. So it may sit on Jack stands for a while waiting on a new pump?
Last edited by msiert; 06-26-2019 at 07:59 PM.
Murray
I need to do a new filter and replace my fuel hoses also. Replaced the filter 3 years ago and it was probably the original.
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