dwe8922

Hi all,
My car is a '95, and when I went out to go to work this morning, it wouldn't start (very bad when it is your only car!). It would turn over fine, but not fire.
It behaved similarly to when I pulled the fuel pump relay a while back (had to leave car outside while on a trip). It turned over and over, but would not fire. Last week, it did the same thing it did today; I was able to let it sit, come back, and it hesitantly started up. This time that did not work. I fiddled with the relays, and did the same with the distributor connections, but none of that worked either.
I drive the car pretty much every day, and did the 30K service 6 mo. ago. All the plug wires look good, and so do the distributors.
I have the shop manuals, and am going to see what I can find out about troubleshooting this now. Any ideas would be greatly appreciated!!!!

David

Ray Calvo

Dan, all I can think of is to check the fuses. Things like good yesterday and bad today makes me suspect electrical stuff (relays, brain) or else something related to the fuel pump.

Good luck.

dwe8922

Thanks for such a quick reply-it is very much appreciated. I went back out, and had someone start the car for me. I checked to see if air was being drawn into the filter, and it was. I also removed the drivers side most rearward sparkplug, and held the end against the motor mount and then against the painted body metal. I didn't see a spark but, it could have been me making a mistake. I checked the fuses too, and all were ok--no starting though. 15 minutes later, I went back out and started the car, and it hesitantly started up. I had to keep the revs up a little, but once it settled down, it idled fine?@?
I'm going to try this process again a couple time today, and see if I can get the problem to show up again. Any thoughts?

Thanks,
David

dwe8922

To add to the above, when I went out to start it up again, and try and drive it, it wouldn't start. Seems to me like something has to be loose, and not broken for it to start once in the middle of all those trys. I guess I'm back where I started.

Carmen

Dave,
Definitely sounds like an electric problem.. look into the distributor.. happened to my wifes honda .. turned out to be the module in it. i thought it was a fuel problem and replaced fuel filter.. etc.

Good luck!!

dwe8922

Carmen,
How did you diagnose the distributor module as being the problem? Has anyone else tried holding the spark plug boot up against metal, while turning the motor over to look for a spark?

Thanks,
David

Ray Calvo

When it runs - no indication of a system malfunction by the dash warning light? If it does light, you try the self diagnosis on Page 24-55 of the shop manual?

I haven't done much (any?) playing on the ignition on these cars, but can you find the 12V power supply to the ignition module? Up on the driver side of the engine compartment, if it's similar to my old '84 (warning - I am GUESSING!). Might check for a loose wire - that's what it sounds like.

Another idea: do you have an automotive test instrument? I.e, unit that includes hi/lo range tachometer, dwell meter, volt/ammeter, etc? If it has a inductive tachometer pickup (type that clips around a spark wire), might hook it up, and watch display as you crank engine. No indication on tach as you're cranking means no spark power.

You been checking the items listed on page 24-29 of the shop manual under "car hard to start"?

Good luck. Times like this you probably wish for good old fashioned carburetors and distributor points (well - almost!)

If I remember, on old Audi Coupe Quattro, when the idle stabilizer died car idling and running was a bear. It would stumble and start, tho.

mani-1

hi David,

you might want to check the engine wiring harness, which has a tendency to effect the starting if water gets into the wires after the cover cracks. i had that problem with my 95 993.

tom_993

I second this opinion, having been through the harness deal myself. Check the archives for more info on this problem. Also, E.J. has a web site with more info at http://www.pcarracing.homestead.com/wiring_harness.html

(Sorry, couldn’t get the URL button to work. I.E. just spun and spun.)

dwe8922

I went out to start the car today, and it started an ran fine!
Robin suggested I check the hot film measuring element in the mass airflow sensor, for being broken, or having a bad connection. I'm goiing to check this out in the morning, but the manual said never to remove the measuring element from the housing because it comes calibrated from the factory in that housing--so I'll look for a bad connection.
Ray--I looked at the diagnostic / troubleshooting section of the manual--24-29, under will not start, but I got the indication that all that info (self diagnosis) was based on the initial fault readin from porsches own fault reading device (9288). Is there a way read faults from some type of blinking diode like on older cars? The pelican board listed fault codes for OBD, and the sequence of pressing, holding the pedal, etc (watching the check engine light), but I haven't heard back on a clarification, and, the manual makes it sound like there is no way to read fault codes unless you have tool 9288.
Tom and Mani; I looked at the posted link, but could not bring up the old archives. I remember reading about people having haywire electrical glitches from it. I will check mine out and see if there is bad insulation. What symptoms did you guys have? Were they anything similar to mine?
Finally, Steve Weiner (who has graciously answered more of my questions than anyone deserves to!!) thinks it could be a fuel pump relay or a DME problem. I plan to get back to him on clarification of how to test relay function.
I guess I'm going to have to sit tight and wait for this little gremlin to rear its ugly head again. I plan to check out the harness, and hopefully learn more about fault retrieval. But, for checking for spark, testing relays, and smelling a plug for the presence of fuel, I'm going to have to wait for the problem to show up again. Suggestions are more than welcome. Thank you all so much for your help! I don't know what we all would do without this community of information.

Sincerely,
David

mani-1

Hi David,
All the problems you listed are exactly like the problems i had before i found out that my wiring harness needed to be replaced. sometimes, after washing my car, i would have trouble starting it for a week until the water would dry up.

mani