Intermittent Starting Problem

DizzyRoc · 02:12 PM

the full story of how it started is here
Intermittent Starting Problem....

now for the cliff notes:

87 944 turbo randomly wont start. Only been remedied so far by waiting it out. Problem usually doesnt last more that 20 minutes. Motor always turns over. Another thing .. Every time it has worked after not starting it starts up one time. idles for 20 seconds and dies. then 2 minutes later. starts up and runs forever

Have had it for 2-3 weeks now. and has started just this past week
things ive done:
1. New DME relay
2. Factory alarm has been bypassed.
3. new spark plugs
4. new oil from castrol 5-30(<--PO) to 20w-30
5. new tranny fluid
6. new front wheel bearings
7. rebuilt cv joints
8. compression test = 150 across

- cap/rotor/wires are ordered but not installed
- found the dizzy cap loose.(bottom screw was not locked) it is now though

what other things can i look for? Its my daily driver so this cant be happening. When its on it has been pretty reliable until this started. steady idle. good oil pressure. And I would like to take care of this myself w/o going to a specialist

Thanks in advance. All help is appreciated.

DizzyRoc · 10-13-2010, 02:13 PM

I had originally suspected the alarm because when i got the car from the previous owner he didnt know that the alarm was the alarm and it was never used. He gave me the key with the description of he did not know what it was for. and i started using it the week before this all started but i have it bypassed at the moment and the problem continues...

sney · sney's Garage

Does the 944 have the cold start valve like the 924 does? The cold start valve is an extra fuel injector responsible for enriching the fuel-air mixture on start and is known to be finicky. My 924 sometimes starts cold and sometimes it doesn't - but if it doesnt, and I open the throttle all the way and try again and that works.

The cold start valve looks like an extra fuel injector plugged into the intake, because that's what it is. On the 924 it's just north of the airbox.

Techno Duck · Techno Duck's Garage

I would check for a leaking fuel injector. Next time it does not restart, pull the plugs and see if they are wet. Also look down into each cylinder and look for fuel collected ontop of the pistons.

DizzyRoc · 10-13-2010, 08:16 PM

ill give them a check tomorrow morning... i didnt think that would cause it to not start. i dont have any rough idles or running issues. but at this point anythings possible right

HondaDustR · 10-14-2010, 06:01 AM

When it dies after 20 seconds, does it die slowly like it's flooding out, losing fuel pressure, or something like that, or does it die instantly like you turn the key off?

S ECU Repair · 10-14-2010, 06:02 AM

Your Dme can be the source of the problem , we can check up your DME and KLR for free to rule out the problem .

DizzyRoc · 10-14-2010, 07:39 AM

it dies all of a sudden like a fuse was tripped or something.

and S Ecu where are you located

962porsche · 10-14-2010, 03:09 PM

i had a 944S in my shop back in june doing the same thing . two other shops worked on it up in mass were he lives and could not fix it . and the owner was going nuts . i told him that fixing a start no start broblem sucks becouse you may install a new part and drive the car for a time then it will not start again . which is what he was going thru . one shop did fuel lines and injectors . the other shop did a used computor . i cleaned the grounds and did the ignition switch . it was the switch . the thing is it could be one of 100 things . i'm in no way saying its the switch on your car but this is the 2nd one i have repaired for that problem . i have also done fuel pumps that would crap out them work along with fuel lines ,ecu, and so on . the worse one ever for me was the 911s alarm . that car you could drive for weeks and then it just wouldn't start . them at times it would and run for about a minute or two and then die .

DizzyRoc · 10-14-2010, 03:32 PM

now that you bring that up.. i did think my ignition switch was a bit funny.. but this was my first porsche so i dont know if that was normal. when i put the key in there are no notches for when you turn it.. it just turns over all the way till you crank it. so like putting it on acc. or on is by feel like if i wanted to just have my radio on.

and the bezel around the cyliner looks as if it had been removed and not installed 100% but its not flush with the rest of the panels and a tiny bit of it is cracked. so I'm thinking somebody was already back there.

Ive got my voltmeter up with new batteries so im going to poke around tonight and see if i can rule anything out

S ECU Repair · 10-15-2010, 08:19 AM

We are located in Fort Lauderdale ,FLorida

DizzyRoc · 10-15-2010, 08:46 AM

i am pm'n you now.. im in miami

Outback Porsche · 10-15-2010, 03:15 PM

Quote:

Originally Posted by HondaDustR

When it dies after 20 seconds, does it die slowly like it's flooding out, losing fuel pressure, or something like that, or does it die instantly like you turn the key off?

It does sound like a fuel pressure problem. There's a valve after the fuel pump that's supposed to maintain pressure in the system, I'd check it.

Cheers,

DizzyRoc · 10-15-2010, 04:45 PM

that wasn't my post... which are you saying it could be a fuel pressure problem if it slowly dies or if it cuts off all of a sudden?

cuz mine when it does this its all of a sudden .. no signs no symptoms just BAM!!! ..im dead and im not starting for ya

DizzyRoc · 09:33 AM

alright so I had two full days of good running till I make it back from the parts store and just as im pulling in the drive way. it dies. quick shut off..

I had the volt meter handy and my battery is at 12.25 volts. when yesterday it was was at 12.59. is there any significance to this? and what else can i check with the voltmeter while its not starting right now so i can rule something out atleast...