itzhypn0tic

Hi, I'm currently trying to figure out why my 1982 porsche 928 is not running. So far i have only been able to get it to actually run or rev when i was spraying starter fluid into the intake but otherwise it will just die and turn off. I have changed the fuel pump, which was bad, and I have made sure that the injectors are powered and that there is good pressure to them. I had gotten this car a while ago and it used to run idle fine but it needed a new clutch so i was never able to drive it. I changed the clutch and then it had this problem and it has been sitting since. I currently think it would be that the fuel injectors are clogged or not opening or that the mass air flow sensor is acting up. If anyone has any advice i would greatly appreciate it.

soontobered84

Replace the Fuel injector relay (XVI) fourth from the top right 928.615.119.00

Rich9928p

Don't overlook vacuum leaks, there are plenty of lines that can leak too much for it to run. I found on my '83 928 Auto Tranny the caps on the side of the throttle body cracked. On 5-speed cars there are two hoses that go to a dampener that can crack.

itzhypn0tic

thanks for the great tips, but right now i am mostly concerned with the mass air flow sensor, would anyone know how to test the mass air flow sensor? (or any other problems such as bad grounds or bad relays etc)
-I don't think it is a vacuum leak because it has ran and i haven't really messed around with it too much for it to create a vacuum leak too great for it to run.(still not ruled out yet though).

Landseer

It doesn't have a mass air flow sensor per se.
It has an air flow meter that rarely goes bad.

Replace or bridge the key relays; clean the electrical panel and all fuse holders, replace with new VW fuses (not BUS as they are wrong dimension).

Clean all grounds. Vac connnections.

No way to test for this stuff / gotta go thru the full list for reliability.

The quirky no start is a signature for these things, 30 years old, with a multitude of pent up maintenance.
If the AFM were even on that list the two guys above would have noted it. Rarely the issue on 82 that fires on fluid.

Mrmerlin

replace the running relays
Start relay if its an auto XIV
Fuel injection relay XVI
Fuel pump relay XVII
Fuse #22 fuel pump, WUR

NOTE check on this fuse that there is power going to the wires on either side of the fuse .
you will need to drop the CE panel to do this,
the fuse may flow power but the contacts may be corroded internal to the fuse holder thus power may not be getting sent to the FP and WUR,
this can cause issues that are hard to find unless you test this as described.

Go to www.928GT.com and print off a fuse relay chart for your car.
Look for page two on the top right then on top left find tips and links
Make sure you have correct part number relays installed in the correct positions .

Make sure that the empty fuse slots are indeed empty by following the fuse chart

itzhypn0tic

for the relays, one or two have either rust marks or burnt marks from a short/ little brown areas. The relays "click" when the car turns on but is it possible that the burn/short/rust can be the cause?

Landseer

Yes, I think definitely so.
Relays have coil and points. They are separate from each other.
They can click, yet not make contact.


Refresh it all. Or punt.

destructo_low

Check the various relays first and jumper the necessary ones to confirm it isn't a simpler problem.

However, my air flow meter caused my car not to run. It acted like you had severely retarded the ignition timing. There was no power, and it would die if you pressed the gas pedal.

This page may be of interest. It covers refreshing your air flow meter. You cut the glue from around the black cover on the housing, and it pulls off, but the glue/ sealant is pretty tough, so the housing will usually chip at the edges when you pry it off.

Testing the air flow meter isn't hard, but I didn't test mine. I just moved the wiper to a new section of resistor track, and I added a wire between the pivoting connection, which is what Bosch did on later models of vehicles. PM me if you open it up, and you aren't sure how to proceed. It's better to be safe than sorry.

-Terell

Kiln_Red

All of the above are good suggestions. Use the reference that Stan cited for a CE chart. Get a helper and have them turn the car over for a few seconds while you kneel at the rear of the car to listen for the fuel pump to run. It will run for a couple of seconds after the starter is disengaged. If it runs, rent a NOID light and check that the injectors are actually firing. Spark should be good considering that the car will run on starting fluid.

Report back with your findings.

TrentonC

just reading this post, but can you clean out the barn-door afm with MAF cleaner? I haven't pulled mine yet, but it looks a little greasy. What about a carb cleaner spray?