Ok, so this car has become the devil. I bought it off of a fellow R3v member about a month ago with hesitation issues thinking it would be an easy fix but it has become anything but that. I have never had a car that has defeated me but this one might. Im about to give up and find a shop that can deal with it.
Background of car: It is a 1987 325is with an M52 block, and M50 head converted to OBD1. When I purchased the car, it took some time to start. You would have to crank it for about 5 seconds. It would start and then idle like crap. You would turn it back off and on and it would idle fine. It would rev fine up til red line as long as you r3ved it slowely and didnt trying to full throttle it. When driving it, under normal driving it seemed fine but anything over about half throttle, the car would hesitate, bog, and had no power. Under full throttle, there was severe hesitation.
Got the car back to my house and started diagnosing. Hooked up the code reader and the diagnostic port had no power. Long story short, took the wiring covers off and what a mess. The repinning made no sense and the easiest way, I thought, would be to tear the wiring out and start over.
So I went to the junk yard, got a new M50 harness with the end of a E36 body harness and took of the old end of a M20 engine harness to create the adapter. I rewired the entire engine, made the adapter, plugged it all in and it started right up. Diagnostic port works now. Throwing no codes though. Took it out for a drive but am having the same issues. It isnt nearly as severe of a hesitation but still there and once in a while, gets really bad and can barely even move the car from a red light. Cant get revs up but once I do play around with the throttle and get them up, its fine again.
I swapped ECU's first. The exact issues. Also swapped throttle position sensors. Same issue. Havent changed injectors yet but i was thinking it was fuel related so i changed fuel pressure regulator first since it was held on with zip ties.
So next, I replaced crank and cam position sensors. No difference. Also, swapped main relays, ECU and MAF. Nothing. It will run great one minute and like shit the next minute. Even when it is "great" there is still some hesitation up high where it is missing a bit.
Then replaced temp sensor for ECU. Nothing different.
Next replaced fuel pump with Walbro pump that came out of my race car, i know it is good. Also pulled grounds off the engine and nothing.
While working on the car yesterday it started doing some even more wierd things. The starter started clicking while trying to start the car but it would keep cranking and eventually start. The interior lights are now flashing when trying to start the car, almost like a nearly dead battery, but that isnt the case. Ive tested power and car keeps cranking and then finally starts. Turned the car off and then tried starting it about 10 minutes later to head home for the evening and now it wont even start. IT cranks and cranks and lightely fires but wont fire all of the way and wont start. After playing around with it for about 15 min and literally doing nothing useful the car finally started but I couldnt get it to r3v or get any power. Kept stepping on the gas pedal trying to back the car into the driveway and then all the sudden it R3v's up and was r3ving with full power again.
I am about to give up. I seriously cant think of anything else to try that might cause this. I used to be all into E36's and recently been all into E30's so I forgot the diagnostics of the E36.
Has any one had any other issues like this or ideas of what i might be? Please help before I go mad.
Update(7/31/12): update: as of today, the car wont start at all. it will crank and crank and wife once but then stops cranking and wont fire beyond one initial fire, if it fires at all.
Update(7/31/12): Found this issue this weekend. I swapped the fuel pump out of my racecar (Walbro 255) which is obviously much stronger. Shortly after that was when the car stopped running completely. I checked the fuel pressure everywhere and ended up checking it right out of the pump. Turns out it was only pushing about 20 psi everywhere. Pulled the pump back out and the 2" rubbing hose connecting the pump to the housing complete blew apart right down the middle.
My theory is that the issue we were having before was that there was a smaller hole or tear in that hose which was preventing the fuel pressure from completely building up.
I replaced rubber hose on housing and car is back in action.
Background of car: It is a 1987 325is with an M52 block, and M50 head converted to OBD1. When I purchased the car, it took some time to start. You would have to crank it for about 5 seconds. It would start and then idle like crap. You would turn it back off and on and it would idle fine. It would rev fine up til red line as long as you r3ved it slowely and didnt trying to full throttle it. When driving it, under normal driving it seemed fine but anything over about half throttle, the car would hesitate, bog, and had no power. Under full throttle, there was severe hesitation.
Got the car back to my house and started diagnosing. Hooked up the code reader and the diagnostic port had no power. Long story short, took the wiring covers off and what a mess. The repinning made no sense and the easiest way, I thought, would be to tear the wiring out and start over.
So I went to the junk yard, got a new M50 harness with the end of a E36 body harness and took of the old end of a M20 engine harness to create the adapter. I rewired the entire engine, made the adapter, plugged it all in and it started right up. Diagnostic port works now. Throwing no codes though. Took it out for a drive but am having the same issues. It isnt nearly as severe of a hesitation but still there and once in a while, gets really bad and can barely even move the car from a red light. Cant get revs up but once I do play around with the throttle and get them up, its fine again.
I swapped ECU's first. The exact issues. Also swapped throttle position sensors. Same issue. Havent changed injectors yet but i was thinking it was fuel related so i changed fuel pressure regulator first since it was held on with zip ties.
So next, I replaced crank and cam position sensors. No difference. Also, swapped main relays, ECU and MAF. Nothing. It will run great one minute and like shit the next minute. Even when it is "great" there is still some hesitation up high where it is missing a bit.
Then replaced temp sensor for ECU. Nothing different.
Next replaced fuel pump with Walbro pump that came out of my race car, i know it is good. Also pulled grounds off the engine and nothing.
While working on the car yesterday it started doing some even more wierd things. The starter started clicking while trying to start the car but it would keep cranking and eventually start. The interior lights are now flashing when trying to start the car, almost like a nearly dead battery, but that isnt the case. Ive tested power and car keeps cranking and then finally starts. Turned the car off and then tried starting it about 10 minutes later to head home for the evening and now it wont even start. IT cranks and cranks and lightely fires but wont fire all of the way and wont start. After playing around with it for about 15 min and literally doing nothing useful the car finally started but I couldnt get it to r3v or get any power. Kept stepping on the gas pedal trying to back the car into the driveway and then all the sudden it R3v's up and was r3ving with full power again.
I am about to give up. I seriously cant think of anything else to try that might cause this. I used to be all into E36's and recently been all into E30's so I forgot the diagnostics of the E36.
Has any one had any other issues like this or ideas of what i might be? Please help before I go mad.
Update(7/31/12): update: as of today, the car wont start at all. it will crank and crank and wife once but then stops cranking and wont fire beyond one initial fire, if it fires at all.
Update(7/31/12): Found this issue this weekend. I swapped the fuel pump out of my racecar (Walbro 255) which is obviously much stronger. Shortly after that was when the car stopped running completely. I checked the fuel pressure everywhere and ended up checking it right out of the pump. Turns out it was only pushing about 20 psi everywhere. Pulled the pump back out and the 2" rubbing hose connecting the pump to the housing complete blew apart right down the middle.
My theory is that the issue we were having before was that there was a smaller hole or tear in that hose which was preventing the fuel pressure from completely building up.
I replaced rubber hose on housing and car is back in action.
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