Couple electrical issues...

[mooserage]

Okay, I finally have time to figure out these two problems plaguing my car.

First: NO Fuel Pump Signal
So I drive my car to get a new tire one day (about 2 months ago), come back, turn it off, decide my parking sucks and go to move it about a minute later. Nothing, won't start, eventually I find that the 12V signal to turn on the fuel pump (that connects to the relay bc my car has a re-wire) isn't sending 12V. So, I try a new MPI relay, but I don't know if it was good or not, so that is still on my list, but it doesn't change. A new ECU and Chip was also added to eliminate those. The car has been driving temporarily with a switch controlled 12V to turn the relay on. So is there anything else to look at besides a known working MPI?

Second: Fuel Cut and TPS CEL
About three weeks ago I swap over new 550s and a keydiver chip, everything goes fine installing. I never touched the TPS. But about three days later I'm driving and notice a CEL, I grab my logger to check it, but it goes away quickly, next time I get it, I determine it is a code 11 for the TPS. The TPS seems fine on the logger, and the tapping test doesn't show any fluctuation in its reading. Most troubling though is that most of the time (with the exception of once or twice) the CEL is preceded by an engine stutter that is EXACTLY like fuel cut, and a click sound from the ecu area, it is loud and noticeable even as the car hits fuel cut. I'm trying to get another TPS, but I'm concerned about the "fuel cut" is this a related symptom or is it causing a false CEL and Fuel cut?

Thanks for any help and time guys.
-shamus

 

[jepherz]

Try a different ECU. My fuel pump wasn't coming on because of that.

 

[mitsuturbo]

I had these exact same problems in 161/2000 shortly after getting it on the road. It would send up a code for tps periodically. It wouldn't start and the FP would not get power. I let it sit a while and tried to start it again, and it worked a few times, but shortly after these issues arose, the ECU crapped out completely. I had bad caps.

You said you swapped in another ECU, so that pretty much rules my particular scenario out.

You should be able to rob a FP relay from any dsm. I bet if you found someone parting one out you could get one for dirt cheap or free.

When the ECU clicks and such.. does the logger lose connection? It almost sounds like your ecu is clicking off momentarily. I also had a problem similar to that when my turbo timer plugs came a little loose.

 

[mooserage]

Yeah, I did try a new ECU, so that is ruled out. I'm going to check the TTimer connections and see if the logger loses connection when it happens, I haven't logged during that time. I'm still sourcing a TPS and another MPI to try as well, we'll see, thanks for the suggestions guys /ubbthreads/images/graemlins/smile.gif
-shamus

 

[mooserage]

Toybreaker has given me a grocery list of things to look at as well, and I'll report back after inspecting all this stuff. Thanks guys
-shamus

 

[iceman69510]

Unless that replacement ECU is tested, repaired or known good, I would still say it might be the cause. The MPI relay relies on the ECU for ground and all the symptoms you describe including the clicking indicate a relay not holding on. The fuel relay ground is one of the first to go when the caps leak.

 

Psh....my turn signals reboot my turbo timer, which doesn't work anyway.
The AFC II always reports 100% no matter how I set it.
Electrical gremlins are the best.

 

[mooserage]

Okay, quick update... I'm an idiot, I've been thinking it was a TPS code (14)and it was actually an O2 code (11), so I'm looking into it, but I don't know why it is throwing that code after clicking off... I'm still testing stuff out, but I thought I'd share my mixup... Thanks.
-shamus