BadComrade

This is naturally what happens when you fix a problem on your car for free... a week later, another one pops up. Here's my new one:

I fixed the ignition cut-out stalling problem I've been posting about by replacing my ignition control module with one from my 83 coupe (after ordering a defective Lucas ICM from Ebay for $10 that changed the stalling problem and made the tach dance all over even when engine idle was steady!). I drove the car for a little over a week with no problems.

NOW, Friday as I was driving to work, I started running out of gas, made it to the station and got a couple gallons and made it to work with no problem. On the way home (6 hours later), the car hiccuped a couple of times, which I just brushed off as possibly the huge puddle I had just hit 30 seconds before, or the fact that I started driving the second I got the car started (sometimes I get a bit of hesitation when I do that, and clear it up by flooring the gas). But of course, further down the road the engine started cutting out as if I was running out of gas again (but I had a half tank). I had to pull over it got so bad. It was really hard to start, and eventually when I would get it started, it ran WORSE than when you pull the fuse to the ECU out. At the time, I was trying to play with EVERYTHING (switched the fuel pump relay with a spare I carry, but no luck) while the car was running bad to see if there was a change. All the sudden the car starts running fine again and 10 min later it acts up again. At one point while it's running rough, I reached under the car (in the dark and in the rain) and shook the fuel pump and played with the wires, and all the sudden, the car idle goes normal, and I'm fine the rest of the way home.

So, the car sits over night, and all the next day. THEN, on Sunday morning, I go out to start the car, and it won't fire. I again try shaking the pump, etc etc and eventually get it running (somehow can't remember how now... maybe just passing time...), and it's fine the rest of the day. Monday, I start the car fine, I drive a couple of blocks, and I floor it. The engine cuts out when I do, I pull off the road, can't get it to start for about 10 minutes, and eventually I get it started, bring it back home, and it runs perfectly the 3 min drive home. I later start it up and drive it around, and it's fine. I'm aware that running the roller cell pump under the car dry can cause damage... but I never really ran it dry... I made it to the gas station, etc. Also, do I remember someone saying something about having problems with less than a 1/4 of a tank of gas "behind" the pump? Also, I know everyone's gonna say to check the fuel filter under the car (I Have a new one somewhere...). I always read that there are TWO fuel filters on these cars (?). Sometimes I see people say that it's near the fuel distributor (I had to replace one on my 83.. I never saw a filter under the hood). Is this 2nd filter that little clearish yellow thing under the car near the pump? I thought that was the accumulator at one point, but now know the accumulator is the metal thing that's after the pump, on the way to the engine....

SO ANYWAY, I decided to swap an ECU from an 86 that I just won on Ebay for $5 (nice!), but I have been afraid to drive the car since I don't know if that's it. The reason I thought the ECU might be bad is because durring the whole ignition stalling problem, at one point when the car hadn't cut out in a while, I had floored the car, and when I let it drop down to idle at a stop, the engine was quickly revving from 1500 to 2000 to 1500 to 2000 (and no, not in a bad ISV way.. this was 2 times a second, the baseline was 1500 and it was spiking to 2000 twice a second... I believe when I unplugged the "spare fuse" to the ECU the problem went away, and came back with the fuse in, but I'm NOT SURE cause I was trying everything I could to find the problem...)

One weird ECU related thing I discovered while searching through wiring while having the ignition problem was a previous owner has INSTALLED A LITTLE RESISTOR (little tan guy who's colored band values I can't recall at the momoent) INLINE ON ONE OF THE WIRES FROM THE TEMP SENDER FOR THE ECU that's under the sender for the temp gauge in the dash. I'm thinking maybe this sender was BAD (and sending a misleading signal to the ECU), and the PO's fix was to use this resistor to lower the voltage (signal) to the ECU. I'm guessing if he did this, then he must have has SOME problem with the ECU, and "fixed" it by using this resistor on the wire.

So is it possible that if this temp sender for the ECU has gotten WORSE that it's sending a signal to the ECU that the resistor can no longer "keep in check" and I'm having these problems that he may have been having?

I really hate owning a car that once was owned by someone who though JB weld, electrical tape and zip ties were a solution....

Again, anyone who may have had a problem like this... please let me know, thanks!

BMWM5

Without doing a presure (6 BAR gauge)and delivery (volume)check, you can only guess but it does sound like a FP taking a dump. In my old days of wrenching we saw alot of failures during the hot season, and these customers ran their cars till empty often. The Fuel pump is both cooled and lubrcated by fuel so running low is like running a engine with out oil or water, not good. Is your car CIS, CIS w/O2, or CIS-E? The resistor is an old trick to fool the DME into thinking the car is allways cold thus richening up the mixture for uber power, take it out. When the WOT switch closes, it goes full power rich anyways.

Spend some insurance money, buy a FP.

Brian

Whitjr

I'm laughing because I get carried away about the stuff I run into on my car as well. Ahhhh, passion!!!

I'd begin checking for wiring around that fuel pump - not in the dark or in the rain! It's likely very dirty down there, and you may have to clean things off to really see what's going on there. Cleaning things there is a good idea anyway for obvious reasons.

Yes there are two filters there, a small one that my have yellowed with age -per your description- and a metal one that is a small PITA to r/r. Again it's dirty and you're playing with gas, etc, etc. I'd also recommend r/r both filters at the same time, before you go down the more expensive lane of trouble shooting relays and fuel pumps. You may have to do all that anyway, but the cheaper fix is better in my book, if that's the prob.


good luck, keep us posted...

BadComrade

Haha... no esspresso for me.

Yeah... the fuel pump is less than 3 years old (looks like it was installed yesterday, and the connections are so shiny and silver I can almost see myself in them)

I took apart the relay in the car, and the one that I had as a spare, examined the solder joints very closely, and discovered on both relays smaller than hair line cracks in a few joints. I'm guessing when I had my ignition stalling problem, all that swapping relays, etc probably put stress on the joints, and I may have been creating a new problem.

I've also swapped the ECU for another one.

I drove the car for about 30 minutes yesterday and it was perfect, but then again after I got the thing started when it'd break down, it'd run fine for that long as well..

Keep ya posted I guess

BadComrade

Seems that it was bad solder joints in the fuel pump relay. I had two that I had been switching between for testing, finally opened them both up, and found cracks in the joints. Soldered one, ran fine for about 2 weeks. NOW, I have a problem where after the car's been running about 15 minutes, the engine will quickly cut out and the back in. I noticed today that I'm a little low on coolant. My temp gauge sometimes comes close to pegging (even on a cool day) and sometimes sits in the middle (even sometimes when it's 09 out...) but I think that's because the sender for the temp guage is going... maybe I'm wrong and the ECU is shutting off the engine cause I'm over heating after all? Who knows if the temp idiot light is in working order... the PO did some weird things in the dash, etc... *sigh*