I know this is a bit long winded, but I can't figure out what the problem is and want to give all the info possible.
1987 325is. It had been sitting for 5 years when I bought it with a blown engine. I replaced the engine, and everything ran pretty well for the first tank of gas. The fuel pump was whirring a bit, and the driveshaft had a serious shake. I replaced the center support bearing after about 300 miles. When I put everything back together, the problems began:
The car would be running well, then instantaneously it would run like shit for 5-10 seconds, it would sputter, check engine light would come on, and run very rich. Then, just as quickly as it began, it would snap out of it and run fine.
I went home and changed the fuel pump/filter (used fuel pump from an 87 325i). The old fuel filter was full of rust and sediment. I figured the old gas tank was flaking off. I wired boat gas tank in the trunk to avoid running into that problem again. (ran fuel hose through the trunk floor to the fuel pump by the fuel filter). It ran great for about 5 miles, then it sputtered and died. It wouldn't start, got it towed home.
I've tried a different ECU, airbox/MAF, spark plugs, and checked O2 sensor connections.
The thing that baffles me the most is how it runs fine, then sputters out of nowhere, then fixes itself for a few miles. I want to say it had something to do with the driveshaft repair, because it happened immediately thereafter, but I wouldn't have touched anything that affects the fuel system. Maybe the O2 sensor hit the subframe and broke it? I thought the O2 sensor didn't affect cold start very much though (and it won't start now).
Any help would be greatly appreciated. I don't have a fuel pressure gauge, though if its really necessary I could go buy one.
Meanwhile I'm about to get fired from my delivery job because my car is shot...This is one of those times where I hate cars...
1987 325is. It had been sitting for 5 years when I bought it with a blown engine. I replaced the engine, and everything ran pretty well for the first tank of gas. The fuel pump was whirring a bit, and the driveshaft had a serious shake. I replaced the center support bearing after about 300 miles. When I put everything back together, the problems began:
The car would be running well, then instantaneously it would run like shit for 5-10 seconds, it would sputter, check engine light would come on, and run very rich. Then, just as quickly as it began, it would snap out of it and run fine.
I went home and changed the fuel pump/filter (used fuel pump from an 87 325i). The old fuel filter was full of rust and sediment. I figured the old gas tank was flaking off. I wired boat gas tank in the trunk to avoid running into that problem again. (ran fuel hose through the trunk floor to the fuel pump by the fuel filter). It ran great for about 5 miles, then it sputtered and died. It wouldn't start, got it towed home.
I've tried a different ECU, airbox/MAF, spark plugs, and checked O2 sensor connections.
The thing that baffles me the most is how it runs fine, then sputters out of nowhere, then fixes itself for a few miles. I want to say it had something to do with the driveshaft repair, because it happened immediately thereafter, but I wouldn't have touched anything that affects the fuel system. Maybe the O2 sensor hit the subframe and broke it? I thought the O2 sensor didn't affect cold start very much though (and it won't start now).
Any help would be greatly appreciated. I don't have a fuel pressure gauge, though if its really necessary I could go buy one.
Meanwhile I'm about to get fired from my delivery job because my car is shot...This is one of those times where I hate cars...
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