intermitent ignition problem 1983 930

mickster8888 · 06-10-2008, 05:47 PM

i have a 1983 930 euro with an intermitent starting problem. sometimes it just dies while driving and other times it just won't start- hot or cold. i replaced the cdi box with a perma tune 6 pin unit, perma tune coil, new green wire from distributor to cdi box, new pickup magnetic pickup coil in distributor. the car is definately getting fuel and fuel pump is working. i don't know what else to try. i was wondering if it could be a problem with wire from ignition switch to cdi box? does the cdi get 12 volts directly from ignition or is there a relay somewhere in between? is there a way to run a temperary wire to find out if there is a break in the ignition wire from switch to cdi? any thoughts would be greatly appreciated. thanks in advance, mick

Flieger · Flieger's Garage

Try swapping out the Permatune blue box with a new unit. I have heard of many failures due to heat, mileage, rough driving, etc.

mickster8888 · 06-11-2008, 01:50 AM

benchtested permatune and everything checked out ok. at first i thought it was a problem with disrtibutor signal but i have replaced everything in that circuit so now i'm thinking it is something else. if anyone has any suggestion please chime in as i'm going crazy.

T77911S · 06-11-2008, 03:23 AM

get a spare sparkplug and when it does not start, connect it to one of the plug wires and check for spark to verify ignition problem.
do u have 2 fuel pumps? verified both run?

john walker's workshop · 06-11-2008, 04:22 AM

next to the rear defog relay in the engine compartment is the delayed ignition cuyoff relay. they fail quite a bit. the power wire to the CD unit goes through that relay on the way to the CD unit. you can bypass it by removing the plug from it and jumping the 12V in to the 12V out terminals in the plug, for test purposes.

MBruns · 06-11-2008, 06:53 AM

Also check the plug in at the side of the distributor, they crumble when disturbed, if you have had that apart recently or just age. Porsche makes a repair section that you can graft into the engine harness with a connector kit.
Mike Bruns JBRacing.com

mickster8888 · 06-11-2008, 02:36 PM

thanks guys, i'm going out to check these things out right now. i'll let you know what i find. thanks again ,mick

mickster8888 · 06-11-2008, 04:32 PM

wiggled a metal rectangular relay in engine compartment and engine started. while running i wiggled it again and it died. the part # on the box is911.615.115.00 made in germany by hella. is this the delayed ignition cutoff relay?

mickster8888 · 06-11-2008, 04:56 PM

just figured out that is the rear defrost relay.found the ignition delay relay and jumped the 2 outer reds and the car fired right up. i very confident this was my problem. before getting too cocky is there anything else i should check? thanks again for all the help.

moneymanager · 06-12-2008, 07:04 AM

Disconnect and clean the several pinned main wiring harness carrying wires rearward from the front firewall. My car ran perfectly, then unaccountably would either not start or would simply die. After waiting a few minutes it would usually start again. Each time it felt like someone had simply switched off the ignition. A poor connection was responsible; drove me crazy.

mickster8888 · 06-12-2008, 05:55 PM

replaced the time delay relay and still have the same problem. however, car will start if i jump out the 2 red/white wires going to the time delay relay. i don't know if it's just a coincidence or what. will it hurt to drive the car with the ignition delay jumped out. will check connection and clean as this seems like a good precaution. i'm starting to get burnt out. what's the chances of the new relay being bad? thanks in advance, mick

mickster8888 · 06-14-2008, 05:53 PM

well after alot of poking around i narrowed the problem down to a wiring issue in the engine compartment near the firewall. when i move the wiring harness towards the firewall i can hear the rear fuel pump shut down and the engine instantly dies. if i pull it slightly away from the firewall it runs. i can't see what is going on up there but there seems to be a loose/bad connection somewhere. is the fuel pump located on the drivers side of the engine compartment? what can be causing this issue? how do i gain access to this area? any help would be greatly appreciated.

moneymanager · 06-14-2008, 06:22 PM

Could be a short somewhere. Could be a bad connection to the fuel pump. Lots of possibilities. Jack the car up on jackstands, crawl underneath with a flashlight, and have someone move the harness as you did. This might reveal something.