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-   -   82 is running again, but has new problems unrelated to voltage stabilizer. (http://forums.pelicanparts.com/porsche-928-technical-forum/597863-82-running-again-but-has-new-problems-unrelated-voltage-stabilizer.html)

Maleficio 03-19-2011 04:34 PM

82 is running again, but has new problems unrelated to voltage stabilizer.
 
Cuts out at 1400 RPM. After good and hot, stalls and won't run. Let it cool, fires up and runs 'til hot, stalls.

Read out Temp II: bad. Thermo switch: out of spec. AFM: 7 to 28 1K ohms low. Temp II can swivel within housing. Twisted, car fired up perfectly, no cut outs until I drove it a short while. Parked it. Will order new Temp II.

Sucks because I replaced it last summer. Cheap part, I guess.

Maleficio 03-19-2011 04:36 PM

Rev past 1400, no problems. Checked switches on throttle housing, good.

Maleficio 03-19-2011 04:39 PM

Cold start valve within spec, too.

Mrmerlin 03-20-2011 10:15 AM

order 4 53 relays as well as the temp2 sender then replace the relays one at a time i will be one of them is weak an once its hot it then gets an open you could also inspect the bases of all the relays for melted or smell for burning

Landseer 03-20-2011 12:41 PM

Order the thermo-time switch along with the relays!

Its similar in the way it mounts to the car, passengerside, but mounts front/back axis as opposed to up/down of tempII.

When you install, no teflon tape. Let them ground to the car.


Sounds like you used manuals to test temp II? each terminal to ground as opposed to across the terminals, right?

Maleficio 03-20-2011 02:03 PM

I read across the contacts and contacts to ground: wide open on all three.

I jumped the contacts in the connector, no difference. Lights off, won't run. I'm now back to the original gripe from three weeks ago when we had the extreme temperature spike and drop from 80 to 25 in 24 hours.

Landseer 03-20-2011 04:43 PM

I should read some resistance (ohms scale). No voltage.

Start with these sensors. Am assuming you've handled all the grounds by now, including inspection of battery ground cable and hot lead and little red wire on the hot lead. All mission critical.

Maleficio 03-20-2011 05:22 PM

Yep, grounds are good. I expect the car will run fine tomorrow. But will fail again.

The Temp II sensor is bad, but think I have more than one failed part.

Maleficio 03-20-2011 05:39 PM

I think the the thermo time switch may be bad, but can't remember the readings.

Swapped out the coil today, no joy.

Put water remover solution in the tank: no difference.

The car will run strong until fully warmed up, which takes a while, then after at temp starts to intermittently cut out, then finally hard stalls while cruising.

Maleficio 03-20-2011 05:41 PM

Only relay is ever hot to the touch: window regulator relay. Jumped the fuel pump relay sockets, pump runs. No joy.

Landseer 03-20-2011 06:02 PM

These are old. You've taken it from garage queen to outside-all-the-time.

Did you systematically clean all the ground points and refurb the CE panel and key relays?
All new fuses. All new sensors. New ignition switch...

Could also be in injector wire shorting intermittently or green wire.

Working on this stuff is pretty necessary.

All that performance enhancing stuff, not so much.

Mrmerlin 03-20-2011 06:42 PM

get into the fuse panel and make absolutely sure that you dont have an extra fuse or two plugged into a slot that should be empty,
this can cause voltage to back feed to other circuits possibly the window relay

Landseer 03-20-2011 10:20 PM

So can a melt on the back. Pull it.

Maleficio 03-21-2011 03:11 PM

I replaced the fuel pump relay: no joy.

But I can no longer hear the fuel pump running.

Would a dying fuel pump cause this problem? If the pump is bad, how can the engine get enough fuel to kick over a few times with pressure? Could the pump be putting out too little pressure?

I verified voltage out of the distributor.

Can anyone recommend a fuel pressure tester that won't cost a buttload?

Maleficio 03-21-2011 03:18 PM

I pulled the vacuum hose from the fuel pressure dampener and fuel spilled out of it. Would this cause enough of a pressure drop to prevent the car from lighting off?

Landseer 03-21-2011 03:20 PM

Its unmetered fuel. Will indeed cause no start or loss of power.

neil30076 03-21-2011 03:24 PM

Yes, WSM vol 1A section 20 page 4 - how to check fuel pump delivery on a AFC system , as in the 82. Requires no expensive tools or gauge, just a calibrated measuring jug!

neil30076 03-21-2011 03:25 PM

Quote:

Originally Posted by Maleficio (Post 5915807)
I pulled the vacuum hose from the fuel pressure dampener and fuel spilled out of it. Would this cause enough of a pressure drop to prevent the car from lighting off?

Fuel in the vacuum line = Bad damper, replace it!

Maleficio 03-21-2011 03:26 PM

Quote:

Originally Posted by Landseer (Post 5915811)
Its unmetered fuel. Will indeed cause no start or loss of power.

It just dawned on me that having extra fuel sucked into the intake may be what's been causing the crazy rumbling at idle.

Maleficio 03-21-2011 03:27 PM

Quote:

Originally Posted by neil30076 (Post 5915822)
Yes, WSM vol 1A section 20 page 4 - how to check fuel pump delivery on a AFC system , as in the 82. Requires no expensive tools or gauge, just a calibrated measuring jug!

Thanks. :)

Looks like fixing this no start is forcing me to uncover all sorts of problems. I wonder how this car even ran before?


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