1988 BMW 325i Convertible motor condition question

[markbimmer]

thanks again. i have 2/4 wood on the edge of the head holding the head elevated so the valves will not hit. I appreciate all your help

[markbimmer]

thanks again for your help. clip arm or pin makes sense to me now---I'm kinda slow on these things---I'm a visual learner and not very good in math but i do want to get the engine right so, sorry for all the questions. I'm also cleaning the gas tank--so far I've removed about 6 gallons of 20 year old gas. I've done this procedure ---drain plug and by removing the fuel pump under the back seat (i have a new pump) on another E30 so it might be a little while before i get this E30 ready to start. i will blow the old gas lines out, evaluate the gas line rubber hoses, install new gas filter. I have all new air and water hoses also that I will install that go under the intake before i re-install it as well as injectors. and new O rings for the bitch tube and zip tie is ready. these are just a few things i will do in the near future.

[82eye]

The clip arm (or pin on other versions) is used to hold the disk from rotating while turning the bolt. Think of it as a ratchet extension with a freely rotating disk on it. If the arm weren't attached to the head in some manner, the disk would rotate with the extension due to the friction. Clipping (or pinning) it to the head stops the disk rotation. The pointer rotates with the extension. As the pointer moves and the disk does not, you measure the rotation angle.

what do think if just re-torquing to spec ? i don't want this going off topic. just curious on your opinion. a couple things have me skittish on angle torquing now. the last two engines i did we did not angle, but did retorque after running. neither were bmw. i have my m20 finished on a stand right now and am eyeing it up for consideration.

edit : part of the issue is the quality of the angle tools available here. loads and loads of bad stories, and i see the exact same one offered under various names all over. we used to angle without a gauge until i busted a bolt. had the same issue with what i consider a crappy one.

thanks again for your help. clip arm or pin makes sense to me now---I'm kinda slow on these things---I'm a visual learner and not very good in math but i do want to get the engine right so, sorry for all the questions. I'm also cleaning the gas tank--so far I've removed about 6 gallons of 20 year old gas. I've done this procedure ---drain plug and by removing the fuel pump under the back seat (i have a new pump) on another E30 so it might be a little while before i get this E30 ready to start. i will blow the old gas lines out, evaluate the gas line rubber hoses, install new gas filter. I have all new air and water hoses also that I will install that go under the intake before i re-install it as well as injectors. and new O rings for the bitch tube and zip tie is ready. these are just a few things i will do in the near future.

you're doing great mark.

[markbimmer]

I'm very grateful for all the help. I got the valves adjusted on the bench. I did it twice and only had to re-adjust 2. I did it on .010 even thought i read in my Haynes manual that it is suppose to be .012. Hope this is right. I should have the head on today. with the last threads i think i'm going to be very careful with torqueing the head bolts. I definitely dont wan to break one off. I did air blow the head bolt ports out last night--that was a good helpful hint and i did clean out the water ports--some of them were nearly stopped up from sitting for 20 years.

[82eye]

i think i'm going to be very careful with torqueing the head bolts. I definitely dont wan to break one off.

torque the head bolts in 3 - 4 stages. first tightening them in sequence at a lower torque, then working up to the torque spec in graduated steps.

[markbimmer]

thanks again--got the head on this evening. i did it in 3 stages so far. I think once i get it hot a few times i will adjust again. I installed the new hoses under where the intake goes. Im preping the intake now, and new water pump, new timing belt, new tensioner, new water hoses, new thermostat, new vacuum hoses, new plugs, re-man fuel injectors, new plugs and new belts, new fuel pump, new fuel filter and extra fuel rubber hoses and extra gaskets where needed. but one big thing that will take a while is cleaning the fuel tank--I've taken out already more than 6 gallons---20 years old gas. Hopefully i can have it mostly back together this weekend. a fun weekend. will give update later.

[dworthy]

So I have always used this 8mm +.010 on every M10, M20, and M30 motor I have owned, and of course dead cold. I remember 8 & 10 to just make it easier and not have too much tap from the lifters. Think of it as a happy sewing machine and you will be good, of course loud taps are not good.

I still have to adjust the valve on my S54 M3, but that one has 24 valve and shims instead of a simple adjuster.

[markbimmer]

Thanks again for all the help. So far I'm happy with the results-even though I'm still in the process of putting it back together. Compression is very good now. I started it for only a second cause i still need to hook up the hoses and belts. A big difference now. Im just taking my time and cleaning everything and replacing all the hoses. belts and fuel system

- - - Updated - - -

Dworthy--good to hear back from you---24 valves are beyond my scope

[dworthy]

It's a bit of a challange, funny enough the kit itself is about half of what I would have paid a dealership to do, and I have done it twice for it's a 60k mile service item. I do it at 30k as I am a bit fickle with the car but at 109k miles it runs like a top.

I do miss messing with an E-30, and once I finish building my garage, I will start looking for a project to play with.

[markbimmer]

All, I finally got everything put back together as well as cleaning the fuel tank. It seems to be running pretty well. Two things Im working on: 1. it doesnt idle the best when cold. 2. there is a noise somewhere --the noise follows or gets louder when i raise the RPMs. it doesn't sound like it is an internal noise so i will try to identify it. I had to order a new timing belt upper cover --I think PO tried to replace the cover--maybe when the belt broke it broke the cover--IDK. but--I do know it is not the correct cover because it doesnt fit perfectly nor does it have the bolt hole to attach the metal water tube that mounts to the cover. So i temporarily drilled a hole in the present cover and attached a bolt/nut to hold the water metal tube. Im thinking this may be where some of the noise is coming from but not sure. So I will let her sit until the parts come in. In the meantime I will work on flushing the brake lines and changing the transmission filter and fluid.

[markbimmer]

I do have another question or two. I replaced the fuel pump. But why does it have to fuel sending units---affects the gas hand? I tried to clean both by letting both to sit in vinegar for a couple of days but i dont think the gas hand works. Also, why do these two sending units cost so much--if i replaced both it would cost around 300-400 dollars which makes no sense to me. Do they have additional functions besides gas hand info.

[82eye]

what's a gas hand lol ?

fuel gauge sender is the float on the in tank pump if that's what you mean.

[richardodn]

gas hand = gauge pointer

There are two senders since the later tanks are basically split and don't always have the same level. The circuit sums the two resistances. On a full tank (sender float at top), each sender has its minimum resistance. On an empty tank resistance is highest. Note that the low fuel light is controlled by a separate switch also located on the in tank pump.

The most common fuel & temp gauge faults are the ground nuts on the back of the cluster that mount the gauges to the cluster's mid-board. This shows up as erratic readings from the gauges. The usual fix for this is to disassemble the cluster and solder brass washers to the board where the posts stick through.

Soaking them in vinegar won't do anything. That can help remove hard water scale deposits and I doubt you have those in the tank. Testing them out of the car is pretty easy. For the left one, measure resistance between pins 1 and 2. Holding the unit upside down should have a minimal resistance. Turning it right side up should show a maximum. For the right side it's similar. Measure between G (brown/green wire) and 31 (brown wire). Results should be the same. W (brown/gray) and 31 (brown) is the is the low level switch. It should be open upside down and closed right side up.

As for your timing cover, it sounds like you currently have the early cover.

[markbimmer]

thanks guys very helpful--i will test the two sending units as described in the reply. I did read about the cluster and ground issue before but never attempted that. I grew up calling the gas pointer or needle in the cluster as a gas hand. I guess that term is not universal lol. I appreciate the help. I believe i got the idle resolved today --just waiting for the new upper timing cover. I did flush the brake lines out today and replaced the rubber brake lines attached to the calipers. the right rear line is not flowing---I will replace the other rubber brake line (s) that are near the frame.

[markbimmer]

question concerning the throttle position sensor. before i re-installed the throttle body --i took the TPS off and put it back on. I see that it can be adjusted--but it looks like it can only be adjusted when the throttle body is removed- does that seem right? is it a common thing to replace on the e30? I read this: Measures the position of the throttle bodies, a common failure item on higher mileage or older vehicles The throttle position sensor, or TPS for short, measures the position of the throttle bodies which is required information for fueling and timing. A failed throttle body position sensors will illuminate a check engine light and cause poor engine performance.

[markbimmer]

question concerning the throttle position sensor. before i re-installed the throttle body --i took the TPS off and put it back on. I see that it can be adjusted--but it looks like it can only be adjusted when the throttle body is removed- does that seem right? is it a common thing to replace on the e30? I read this: Measures the position of the throttle bodies, a common failure item on higher mileage or older vehicles The throttle position sensor, or TPS for short, measures the position of the throttle bodies which is required information for fueling and timing. A failed throttle body position sensors will illuminate a check engine light and cause poor engine performance.

[82eye]

question concerning the throttle position sensor. before i re-installed the throttle body --i took the TPS off and put it back on. I see that it can be adjusted--but it looks like it can only be adjusted when the throttle body is removed- does that seem right? is it a common thing to replace on the e30? I read this: Measures the position of the throttle bodies, a common failure item on higher mileage or older vehicles The throttle position sensor, or TPS for short, measures the position of the throttle bodies which is required information for fueling and timing. A failed throttle body position sensors will illuminate a check engine light and cause poor engine performance.

it get's adjusted while partially installed. you need a feeler gauge and an ohm meter. i think jeffnhiscars posted the procedure. it's probably in the trouble shooting faq as well.

edit: they do go bad. the placement on the e30 is not the best.

[markbimmer]

thanks B2eye- i will look for the procedure --i have a feeler gauge and ohm meter so shouldn't be too hard

[richardodn]

The TPS on the M20 is a switch and not a sensor. It only indicates closed and wide open throttle (WOT). Inside are a couple of micro-switches. The usual failure mode is oil slowly travelling down the throttle shaft and into the switch where it has nowhere else to go. You can drill a couple of small holes into the plastic cover (don't go too far) to prevent oil from accumulating.

[markbimmer]

finally all the parts i needed came in. once i put the new timing belt upper cover on and a couple of other little things--the noise that i was hearing previously is no longer there. i drove it today in the yard. It runs super well once it warms up--but starting cold it dies and idles a little rough until it warms up--it is idling at 800 rmps and once warm it holds it and idles perfectly. any thought on what i can do to make the idle work ok on cold start?

[sienayr]

-clean the ICV if you haven't
-smoke test for vacuum leaks when the engine is cold

This is a great resource for systematic troubleshooting of various issues with the motronic fuel injection system. It's written for an e28 but most of it applies to the e30 motronic system as well. This article helped me get a better overall understanding of the system than any other resource. And most importantly provides a systematic troubleshooting/testing framework so you don't have to guess and throw parts at problems hoping for the best.

https://hpsimotorsports.com/blogs/te...n-tech-article

[dworthy]

+1

Look for vacuum leaks, and as a short test, unplug the AFM to see if the problem goes away.