Random stalling, possible fuel pump issue?

acidgear 101 · 07-18-2010, 10:55 PM

My 85.5' 944 N/A recently started acting up on me, first on the freeway it just died on me and when I tried to started it again, either it just kept cranking over or would start and die immediatley. Later it started up just fine and ran for several minutes no problem. Convinced it would happen again, I went ahead and replaced the DME relay as suggested in another posting. I drove it for almost 50 miles the following day without a hiccup and then next day it didn't even make it out of the driveway

So at this point I'm lost on what to do and think it may be a bad fuel pump because I can't hear it when it starts up or when I put the key to RUN. I'll check it again tomorrow but in the mean time I just wanted to know if there were any solutions out there. Thanks for any help.

fmartenies · 07-19-2010, 03:53 AM

Do you know if the plugs are wet or dry afterward? That would narrow it down between fuel delivery vs spark problem. I'm guessing dry but worth checking.

Born2bwild1191 · 07-19-2010, 04:17 AM

Had an identical problem...Probably fuel pressure regulator...unplug an injector and try to start. If it starts and stays running (will be rough of course), it's your FPR. Cheap and easy to install.

desertt5 · 04:33 AM

Is the fuel pump running when you try to crank it? It does not pump until the starter is engaged ( unlike other cars that 'prime' the system with the key on. Try and make a jumper for the DME relay. Clarks garage has the info to do it. My 944S has been having strange issues like you described. i finally tracked the lastest one to the DME itself.

With a jumper in palce of the DME relay it would run fine. Brand new realy = no fuel pump/ pressure. The DME was not sending the ground to the realy. ( I don't think this is a comon problem though)

Barry Johnson · 07-19-2010, 07:45 PM

Here's a LONG shot, but it did happen to a local car up here...

Check the connectors on the underside of the relays. The car in reference had a loose connector to the DME relay and would act pretty close to how yours is sounding. Quick thing to check out, and a little piece of mind

That reminds me, another idea! Check out your wiring to the air flow meter and your injectors. I'd agree with desertt5 and do that first though, solid advice.

Good luck!

acidgear 101 · 07-22-2010, 02:17 PM

Quote:

Originally Posted by Born2bwild1191

Had an identical problem...Probably fuel pressure regulator...unplug an injector and try to start. If it starts and stays running (will be rough of course), it's your FPR. Cheap and easy to install.

Looks like Born2bwild1191 was right on the money, it died again this morning and ran after I unplugged one of the fuel injectors. Already have a new one and will install it tonight, hopefully that fixes the issue. I'll let you know if anything crops up but want to thank everyone for their swift and helpful replies.

Born2bwild1191 · 07-23-2010, 03:41 AM

Awesome, glad we could help! Good luck!

desertt5 · 07-23-2010, 04:53 AM

Glad you got it figured out.

I broke down when mine was being a beeotch, and mounted a fuel pressure guage on the fuel rail. Worth the $70 IMO. Last time my DME crapped out, made troubleshooting on the side of the interstate very easy.

acidgear 101 · 07-23-2010, 10:41 PM

Quote:

Originally Posted by desertt5

Glad you got it figured out.

I broke down when mine was being a beeotch, and mounted a fuel pressure guage on the fuel rail. Worth the $70 IMO. Last time my DME crapped out, made troubleshooting on the side of the interstate very easy.

Might just invest in one of those, it would make troubleshooting much easier.