flash porsche

Hi All,

I searched about 500 archives of a no start, hard start, when warm, cold etc. But not many have posted a solution to their start problems. Did you ever get the problem fixed? Did you give up and sell your 928. Did you take it to a mechanic? If so, what were their findings? If any of you posted your starting problems, please follow up that post to the source of the problem. A follow up to a mechanical troubleshooting problem is an excellent source of tech info to 928 owners. It helps others try and pinpoint the problem. I am at my witts end with testing all the components on my car. Maybe I just need to have a few drinks and try and regain my patience. In other words, this car is driving me to drink. Thanks.



Joe Flash

j.kenzie@sbcglobal.net

My 84 would start and run only when I had the key in the START position, and die when I released the key. I had just replaced my starter because of sqealing noises it seemed to be making. Of course I blamed something I broke or goofed up. It turned out that it was the new starter itself. The starter has two switches inside it: one to engage the starter/solenoid and the other to bypass one of the ignition resistors to increase coil voltage during starting, and resume two resistor configuration during running. This second function failed by shorting to ground in the RUN position. It took a second new starter and a lot of help from Chris (Landseer) and Sharskin, to get this working again.

flash porsche

Hi J.

Thats very interesting that the starter caused this problem. I guess its mostly electrical problems with these cars. The problem is that there is so many electrical parts to check. Its takes a long time to track down the problem. I guess thats another thing to check on my list. When I find out what it is, I will post it for all to see. Thanks for your help.



Joe Flash

Mrmerlin

well since your having some kind of starting problem,
try reposting your conditions,
and what you have done ,
and what was the last thing you fixed,
and what year model

DR

Here is a classic from many years ago.

81 L-Jet
Sitting for 2-3 years.
Would start and run for approx 5-10 seconds.
Unplug cold start valve, would not run at all.
Injection relay tested good
Verified voltage pulse to injectors
Verified Fuel Pressure

Scratched head for a few minutes...

Loosened 4 injectors on one side and lifted out of intake (injectors still attached to rails)

Tried to start it again, and NO fuel coming out of the injectors (remember above, proper voltage pulse to injectors and good fuel pressure)

Replaced fuel injectors, fired up and ran perfectly.

End result - Injectors were 100% clogged from sitting for so long.

Nightfly

Mine needs a full battery charge to start; anything less and it will turn over until the battery is completely drained. Oh, the engine will turn over as fast as seems normal well, and seem to start to 'catch', but if it has been sitting for more than a week and it's cold outside, it will never start, and this will go on for half an hour or so, with rest between attempts. BUT.....charge to full, and it starts fine. Solution; drive it a lot. Seems to work fine for me. I'm guessing there's some weak link in the system somewhere, because I have gas, I have spark, and I have air. But without a full charge, it simply won't start.

Mongo

Plugging my oxygen sensor in causes my 1987 to run hideously rich, sputter and stall. Mine is disconnected and car runs strong leading to a bad sensor.....2,300 dollars later for new everything that has to do with ignition and LH.

Tampa 928s

You said you had an aftermarket alarm is that right? If your car is running with the relay removed most alarms disable the FP relay or Injectors. I would start looking at that next.

sendarius

From a week or two after I put my '88 S4 on the road as a daily driver.

I left the office to head home. Car started, then died a couple of seconds later. Nothing I did could convince it to fire after that. It cranked fine, but there was no fire.

Dive into the CE panel, replace the one partly melted and comprehensively blown fuse (#42), and it fired up straight away.

Following weekend task - remove all fuses, replace with new. No issues since.

John Speake

Manual gearbox car ('87 I think) - someone had fitted a kickdown relay to the car while finding the real fault. This gives a no-start.

Landseer

84 5speed. Temp / Time switch.
84 Auto AFC relay
84 5speed Fuel pump relay
84 5speed Ignition switch
85 Auto Battery ground cable, debilitating corrosion under plastic covering, near body attachment point

flash porsche

Hi Guys,

Great responses. I cant really post the solution to my start problems until I replace my green ignition ignitor wire and fuel pump relay. Car starts, runs for 3 seconds, then dies. Second try, yes. Wait a minute then third try. Does run for two minutes with AFC module and fuel pump relay disconnected. With no fuel pump operation. I checked everything. Hoping these two items will correct the problem. Stay tuned.


Joe Flash

cfc928gt

My '89 GT had three times it wouldn't start over my 9.5 years of ownership:

One of the three arms in the clutch pressure plate broke and centrifugal force pushed it out so that it took out the crank position sensor. The car won't start without a pulse from it.

I suspect the intank pump failed and pieces from it then took out the outer pump - no fuel, no start, replace both pumps.

Refreshed the intake and somehow missed reconnecting the right rear ground wire for the fuel injectors. Might start for a minute and suddenly die, might not start at all.

Landseer

Another. Thanksgiving morning.


85 Auto.
Brother in law and I had run it moderately hard for about 50 miles after re-seating the MAF,
Stopped at a food store for beer.
Came back out, restarted, would not run right, stalled if any throttle was applied.
Would kind of idle continuously, but not well.
My fuel pump cover was already off. I got out of the car and held my hand on fuel pump / pump wasn't running.
Turned off the stumbling/idling car. Grabbed the wiring diagram from the door pocket. Pulled relay XX (fuel pump) and inserted jumper / pump began to run.
Turned ignition. Car revved great.
Turned it off, removed the jumper.

Banged relay XX 3 times against the rocker panel. Reinstalled the relay.
Car restarted (brother-in-law now laughing his *** off) and we drove home.

By the way, the panel was polished clean, fan is sealed so no leaks, car had been in the garage for a week prior to driving and relay was brand spanking new 2 months ago (I had replaced 8 at once). All fuses new too.

shmark

Mine was a little different and self-inflicted, but it points to causes other than electrical sometimes. I had installed a fuel pressure gauge in the passenger fuel rail but did not clip the rubber nib. It blew out and then the rails would not hold proper pressure when the engine was hot. Result - cold start just fine, running just fine, but then hot start failed due to vapor lock. I installed a new pressure gauge correctly and not one problem since. FWIW similar problems can happen if the check valve is bad.