85 ETA issue.

[donaldvw]

i bought this car back in july. non-running after doing few things i came down to the problem. bad main relay. after i put a new one in. fire right up. some fresh gas and she purred.

but when i drive it, whole different story.

when i'm going through first has pulsation. like im letting off the gas and getting back on it. very small and hardly noticeable, you can only feel it in the pedal.. but when i open the throttle all the way up runs right. but then at times when i stomp on it. completely bogs down for a few seconds. if i were to left off the clutch the engine completely shuts off. but if i keep the clutch in it catches back up and just jerks starts back up, and goes on. and it'll do it anytime i shift gears. so i have to baby it 24/7 usually have to ride each gear out past 3,500 before i can shift. or it just bogs.

i have replaced
cap
rotor
wires
coil
DME
plugs
timing belt
fuel filter
fuel pump
intake gaskets
intake boot.
new MAF
and not a single change at all. when i replaced the intake gaskets looked like four of the six injects has some leaking. could they be staying open. i've read that this can be a common problem on the early M20?

its very hard to explain. it would be more clear if you were in the car. but thats the best i could do.

any information. would be great. and highly appreciated.

thank you -donald

[rich325e]

Check the O2 sensor connector under the car for corrosion. I had a problem with my 85 325E where it would hesitate, stumble on acceleration for a few seconds. Replacing the O2 sensor solved the problem. I replaced it with a bosch O2 sensor that had a longer cable to eliminate the connector under the car, thus keeping the connector from getting wet and corroded. The part number at autohausaz.com is 13049

[donaldvw]

I should try this, but let me ask this. Say I have a good o2 sensor.... When I un plug it and then drive the car. Should I see a difference? Cause when I in plug mine. There is no difference.

[jlevie]

You probably won't see an immediate difference when you disconnect the O2 sensor. But a new sensor may help after the car is driven a bit. I'd also suggest that you replace the timing sensors.

[donaldvw]

You probably won't see an immediate difference when you disconnect the O2 sensor. But a new sensor may help after the car is driven a bit. I'd also suggest that you replace the timing sensors.

I did forget to add. I have replaced those!

[rich325e]

If you unplug the O2 sensor, you will always feel the hesitation on acceleration. You should also check the back pressure on the exhaust, it is possible the cat may be partially clogged.

[donaldvw]

If you unplug the O2 sensor, you will always feel the hesitation on acceleration. You should also check the back pressure on the exhaust, it is possible the cat may be partially clogged.

i gutted the cat completely. not a change whatsoever.

[DaButt]

This ever get fixed? I tell you this is killing me. I'm able to find a lot of people who have the same symptoms, but there are so few threads where the fix is published... Makes me want to ask the mods to Sticky the ones that contain resolution.