M20 power loss over time

[ElijahKnapp]

I have a 325es e30 that is losing power over time. When I first got the car it was a lot quicker and would spin the 205/50/15 tires. Overtime it's been getting slower and now it will die out if I try to do a burnout on even 165/45/15's. compression is great along all cylinders and fuel pressure is not an issue.

[Old525i]

Clutch?

[ElijahKnapp]

Clutch?

originally the clutch was starting to slip and I thought that was the problem, I replaced it and put a lightweight flywheel in. Noticed the increased rev from the flywheel but still has low power. Did a full tune up as well as a Walbro 255 fuel pump and changed my CPS. Still nothing.

[mikebloco]

Slap an i head on it. Maybe your valve train is just old and worn out. How many miles are on it?

[modernist]

Slap an i head on it. Maybe your valve train is just old and worn out. How many miles are on it?

modding an engine with problems is not going to be fun down the road

[ElijahKnapp]

Slap an i head on it. Maybe your valve train is just old and worn out. How many miles are on it?

I have a whole 325is swap sitting in my garage, but I would like to figure out why this motor is running so low on power for the time being. Unknown miles on the motor. The previous owner said it was swapped in with about 120k miles so if he was true to his word then around 140-150k. I've adjusted the valves and no improvement either. Compression on all cylinders is inbetween 185-195, and my fuel pressure is at 28psi at idle and goes to roughly 36psi WOT. Could the AFM be causing an issue like this? Or a CAT that's going bad?

[Andy.B]

Failed catalytic converter restricting exhaust flow? Bad o2 sensor? Worn cam lobes?

Vacuum leaks? Probably vacuum leaks.

[Old525i]

I have a whole 325is swap sitting in my garage, but I would like to figure out why this motor is running so low on power for the time being. Unknown miles on the motor. The previous owner said it was swapped in with about 120k miles so if he was true to his word then around 140-150k. I've adjusted the valves and no improvement either. Compression on all cylinders is inbetween 185-195, and my fuel pressure is at 28psi at idle and goes to roughly 36psi WOT. Could the AFM be causing an issue like this? Or a CAT that's going bad?

That pressure is too low. I think it should be between 40 (high vacuum) to 50 (WOT) PSI. I suspect a plugged fuel filter.

Check this out: http://oppositelock.kinja.com/solvin...oss-1612064631

[digger]

eta has lower fuel pressure, maybe it should be closer to 31psi at idle? pull the vacuum hose and see if you get 36

[ElijahKnapp]

Failed catalytic converter restricting exhaust flow? Bad o2 sensor? Worn cam lobes?

Vacuum leaks? Probably vacuum leaks.

O2 sensor is brand new. Has this issue with or without the o2 sensor plugged up. Not sure how to check the cam lobes. I think the cat will be the next thing I check. Just cut pre cat, see if it free's up the power and if not I'll weld it back up. Unless there's an easier way to check the cat?

[ElijahKnapp]

That pressure is too low. I think it should be between 40 (high vacuum) to 50 (WOT) PSI. I suspect a plugged fuel filter.

Check this out: http://oppositelock.kinja.com/solvin...oss-1612064631

Fuel filter was replaced about a month or 2 ago. Don't think it would be plugged so quickly. My in tank pump went bad and my in line pump started to go bad so I did the conversion for dual fuel pumps to a single in tank Walbro 255. Fuel pressure has been the same since I did those. I believe the 40-50psi is for a 325i but I'm not for sure. Maybe if I install an inline pump again my pressure would bump up? I'm running the same Walbro pump a 325i would use.

[ElijahKnapp]

Oh and here's a picture of my car since I'm a stranger on the forums

[Kershaw]

You can't do that on an eta. You need the 2 fuel pumps. They have a different fuel line routing system. The in tank pump is just a transfer pump, the high pressure pump is outside.

I'd swap the fuel pumps back and see what happens.

[TobyB]

I think those rimzzzz are a big part of your problem..... you're not gettin' the powah to da pavement....

t

[packratbimmer]

If you are running the original 2.79 or 2.93 diff, the light flywheel might have caused a loss in low end torque needed to run those gears. Maybe try a 3.25 or 3.46. Lightening the flywheel will make an eta rev quicker, but there is no high end to rev to with the 4.5K rev limit.