How to diagnose and resolve engine issues using Durametric.

[jb92563]

Originally Posted by wawa

I had change the fuel pump without any change. I had been told it usualy is not faulty, but I didnt want to take the chance.

You could try passing a second ground wire and run it for a time to see if it still happen?

Later

Wawa

Being that it is intermittent and seems to be all or nothing, working as normal or running bad, its hard to imagine a fuel pump failing in that way, unless there is an obstruction in the tank.

Perhaps its worth a look at least as I have heard of one fuel pump that broke free from its brackets and was hanging loosely in the tank by its hoses.

You never know if someone has shoved a plastic bag up the fuel noozle so the next person pumping gas gets it in his fuel tank.

[jb92563]

The saga continues and I'm near the point of giving up and taking it to an indy and letting them try.

I read some stuff about testing the MAF for a bad ground so yesterday I was fiddling with the MAF and trying to get my
multimeter hooked up so I could test the ground in situ.

I used sewing pins in the top of the MAF harness to make the connections but something slipped and the
MAF ground pin touched (shorted) the Supply 12v pin.

I heard the throttle plate make a hard smack at the same time and feared I damaged something
with the momentary short.

I then started the car and the Egas throttle was unresponsive, although the car started and idled.

I checked all the fuses and they all seemed fine.

I reset the computer disconnecting the battery, no luck, still no gas pedal response.

I checked the codes and the Egas Potentiometer codes are now present with implausible reading,
as well as the throttle position sensor codes and the MAF code that was there before.

I hope I did not fry something.

I took the throttle body apart and looked at the potentiometer and it looks fine and does not smell burnt.

I'll need to find the Egas potentiometers next and see if they look OK.

I hope the ECU is ok, as the car runs and otherwise functions properly.
Just no gas pedal response.

I wonder if the ECU has its own fuses?

It still acts like the ground is bad for the MAF so I read that the C9 pin at the ECU is the MAF ground
so will check that as well.


I found these helpful but I need to add a DSO scope to my toolkit.
https://www.youtube.com/channel/UCrf6f8hn5oy4alB2WXJCIqA

[jb92563]

Ordered a working Throttle body and Pedal module from a dismantler.

Hopefully that will fix my "Mistake/Accident" issue.

If not then I'll have to take a look at the ECU to see if it got damaged.

I also bought an ECU, Immobilizer, Ignition/key assembly matched set in case i need to try the ECU replacement, only $265 delivered for all 3 for my exact model year 2001 S.

I also discovered/read about another set of high amp (60A+) fuses hidden away in the car but I doubt these have anything to do with my problem.

I'll try the Throttle body first, then the pedal, ECU is a last resort.

[jb92563]

Update -

I tried swaping out the Throttle Body and the E-gas pedal potentiometer/sensor and still no luck.

The car starts and idles ok but does not respond at all to the gas pedal.

It just seems like there must be a fuse somewhere thats blown but all the fuses look good except the drivers seat adjustment, which has an issue that I know about.

I also found some more relays and fuses in the trunk but the fuse there looks fine as well.

I also disconnected the ECU in the trunk and used contact cleaner on the pins.

I took the ECU apart and nothing looks burned or fried. Solder joints look good.
I was surprised the ECU is not even a sealed unit, and looks cheap. Any moisture in the trunk would be a bad thing for sure.

As a last resort I have a matched used ECU/DME/Ignition assembly for a 2001 S same as mine, so I'll give that swap a try and keep my fingers crossed.

If no luck then I need to find a very talented Indy with the right skills and tools to figure this out.

Still the same codes for the egas potentiometer, Throttle Body and MAF but those are symptoms, not the root cause, as my swaps have proven.

No Check engine light suprisingly.

[woodsman]

Wow- just read the whole thread. It's been a while-- have you taken it to a pro???? If not keep up the good fight! Either way I appreciate that you've detailed your efforts...

[jb92563]

Originally Posted by woodsman

Wow- just read the whole thread. It's been a while-- have you taken it to a pro???? If not keep up the good fight! Either way I appreciate that you've detailed your efforts...

This weekend I will replace the stock ECU, Immobilizer and ignition assembly with the matched set I got from a dismanteler.

Wish me luck!

If that option fails then I need to talk to a good indy with the diagnostic tools and experience to figure out what is going on, as I have replaced a lot of stuff already, all the typical suspect things.

Im having Boxster driving withdrawl symptoms too so I need this resolved soon.

[Topless]

Wow is right.

Try the new DME and if you don't get results it is probably time to take it in. Document your path so they know where you have been and why. Black Forest in SD might be the best for diagnosing phantom issues like this. Good luck Ray!