m42b18 engine problem, periodic power loss

[eric16v]

Quick question? Regarding this fuse able link. If this connection is corroding and looses contact will the car still run? I am having issues with my car periodically loosing power. The engine will begin bogging down. When i press the throttle nothing happens but the engine is still running. I usually have to clutch in and rev it up a couple times before i can get it going again. Usually running like crap. After a while it seems to run ok for weeks and even months. Very intermittent that it's frustrating to isolate the issue. Not sure if anyone else has had these issues. Any help is appreciated.

TIA,
Eric

[DesktopDave]

I split this post off, so you'd get a little more visibility. First thing I'd check is the throttle body switch and the AFM.

The fusible link is usually damaged after a jump start. IDK if it can corrode, it's really tightly covered up. I guess it's possible though. You checked the firewall drain, right?

I would be very interested in all the harness grounds, especially the one off the block and the positive terminal block on the firewall. I'd also be interested in the fuel pump, filter, main relay and fuel pump relay.

[eric16v]

Ok. Thanks for the reply and giving me somewhere to start. I had a fuel pressure test gauge hooked up in line on the bottom fuel line at the rail and it was reading 38 psi. The thing is i am having trouble testing it because it seems to run good whenever i have it hooked up. Very frustrating. I will check out the grounds aswell.

The weather doesn't seem to have any effect on the performance. Filter is somewhat new maybe a year old. I did run the tank down trying to see what mpg im getting. After filling up it seemed to be surging a bit at idle. I wonder if this has something to do with it.

[DesktopDave]

I'll bet that's a fun one to track down. I've seen a few symptoms like yours when the pump or pump relay was giving up the ghost. Otherwise, I'd suspect an electrical glitch, like the throttle sensor or the coolant temp sensor. The Bentley manual has a good troubleshooting guide.