J.DeFeo
05-31-2007, 06:59 AM
After sitting for a while (at least several hours), my car, a 1992 535iM with 128,000 miles when starting would have several issues:
1.) The engine would vibrate hard.
2.) It sounds and feels like one cylinder wasn't firing correctly.
3.) If throttle wasn't added, the engine would almost immediately stall.
4.) If the throttle is held, eventually (about 10 seconds) the engine would smooth out and idle normally.
5.) A faint odor of fuel in the passenger compartment.
There are no codes, no CEL, no warning lights of any kind. I just replaced the fuel injectors (albeit with used ones, but what are the chances that two sets of fuel injectors both leak?). The sparks plugs are basically new (<1000 miles on them). When I replaced the spark plugs, there did not appear to be any oil on them.
After replacing the fuel injectors, the problem completely disappeared for a couple days. That is, until this morning, when the exact same problem resurfaced.
I'm thinking now it's time to crack out the ohm meter and start checking sensors. Likely candidates I can think of are: TPS (not signalling idle correctly), ICV, Coolant Temp. Any others? How do I check these sensors? What values should I get when I check them?
Is there a way to tell definitively if there is a fuel injector leaking?
Occam's Razor says my "new" injectors are probably also leaking. But the more I think about it, I think zebra is actually the correct answer here. The injectors were part of the problem, but now another has come to the forefront.
I'm getting fairly desperate here. Any suggestions and advice at all would be greatly appreciated. If I can't figure this out, I'm just going to... :( ...take it to a mechanic. Any other information needed I can supply, I have a full maintenance history for the car.
1.) The engine would vibrate hard.
2.) It sounds and feels like one cylinder wasn't firing correctly.
3.) If throttle wasn't added, the engine would almost immediately stall.
4.) If the throttle is held, eventually (about 10 seconds) the engine would smooth out and idle normally.
5.) A faint odor of fuel in the passenger compartment.
There are no codes, no CEL, no warning lights of any kind. I just replaced the fuel injectors (albeit with used ones, but what are the chances that two sets of fuel injectors both leak?). The sparks plugs are basically new (<1000 miles on them). When I replaced the spark plugs, there did not appear to be any oil on them.
After replacing the fuel injectors, the problem completely disappeared for a couple days. That is, until this morning, when the exact same problem resurfaced.
I'm thinking now it's time to crack out the ohm meter and start checking sensors. Likely candidates I can think of are: TPS (not signalling idle correctly), ICV, Coolant Temp. Any others? How do I check these sensors? What values should I get when I check them?
Is there a way to tell definitively if there is a fuel injector leaking?
Occam's Razor says my "new" injectors are probably also leaking. But the more I think about it, I think zebra is actually the correct answer here. The injectors were part of the problem, but now another has come to the forefront.
I'm getting fairly desperate here. Any suggestions and advice at all would be greatly appreciated. If I can't figure this out, I'm just going to... :( ...take it to a mechanic. Any other information needed I can supply, I have a full maintenance history for the car.