Problem won't go away :(

[Interceptor]

OK, guys, I'm starting to freak out a bit. Since I bought the car (9 months ago!) I replaced the following: battery, injectors, fuel pump, oil pan gasket, upper & lower control arms and hood & trunk gas lifts. Will this continue? My wallet is getting thinner and thinner as days go by!

I still haven't solved one problem - slight stalling upon acceleration followed by a slight loss of power in the higher rpms. Also, it's not so noticable when the engine is still cold and it revs OK when the clutch is depressed. I passed the emissions test with flying colors (lambda 1.00) and performed the clutch test successfully. I'm open for suggestions - in fact, I'm desperate, please help!

[philbyil]

By any chance, did the stalling and power loss start after you installed the Iridiums?

[Interceptor]

By any chance, did the stalling and power loss start after you installed the Iridiums?
No, it actually improved performance a bit. I suspect that there is a vacuum leak or something? Can the exhaust system interfere with engine behavious? I have a few holes in the muffler :)

[epj3]

Sounds like it could possibly be a vacuume leak. I would check everything that has to do with the intake, and the fuel delivery.

All boots, gaskets (IE Valve cover gasket - my friends 1994 325i had a bad valve cover gasket and it cuased vacuume leaks and slight jerkyness at upper rpm's). Also check the fuel pump relay, fuel filter, etc.

[Kalevera]

Neglected (even slightly) cars are expensive :( Ask me how I know or do a forum search to see the list of things I've done since I bought the car (7 months ago).

Now, when the fuel pump was replaced, was a pressure test performed? The reason I ask is, there are other system components that could cause said problem that might be elucidated by a pressure test.

Also, what kind of injectors were installed? The OE or ?

Personally, I'd be using the normal spark plugs, and I'd also check the ignition system thoroughly. I don't know if it's the W8LCR for the M50, but the wrong spark plug will mess things up.

best, whit

[632 Regal]

ditto the fuel test and stocker plugs.

[winfred]

BKR6EK ngk's or F7LDCR bosch's for m42/44/50/52/60/62 and i've used them in 850/960 volvos


Personally, I'd be using the normal spark plugs, and I'd also check the ignition system thoroughly. I don't know if it's the W8LCR for the M50, but the wrong spark plug will mess things up.

best, whit

[winfred]

the problem sounds sorta like a dieing air flow meter, find a buddy with a same part# unit on their car and do a quick swap to see if that's the problem

[Interceptor]

Sounds like it could possibly be a vacuume leak. I would check everything that has to do with the intake, and the fuel delivery.

All boots, gaskets (IE Valve cover gasket - my friends 1994 325i had a bad valve cover gasket and it cuased vacuume leaks and slight jerkyness at upper rpm's). Also check the fuel pump relay, fuel filter, etc.
Fuel pump and fuel filter have been replaced recently because of the fuel pump bearing failure (hissing sound from the back of the car). Where is the fuel pump relay located? Under the rear seat in the relay box?

[Reuben Lim]

When I got my 525 M20, went through many repairs, even did a transmission rebuild coz my mechanic at the time thought it was the clutch slipping that was causing my power loss at higher gear. At some point, the car would actually slow to a crawl though my foot was on the accelerator at speed. The engine didn't stall, but I couldn't go beyond 2000 RPM. The rebuild, and other expensive stuff I did failed to solve problem. Changed mechanics, the new one took down my gas tank, drained it, cleaned it out after he saw a lot of junk like tiny foam bits floating around. At least that's what he said he did, didn't charge me a lot, too. That solved the problem, was so happy.