TheDice951

I’m starting from the beginning,
Wouldn’t start on trailer, pulled fuel pump fuse and it started and ran out of fuel, put fuse back in and it started and idled fine, but rich.
Pulled it off the trailer and parked in the driveway.
Drove it around the nieghborhood and seemed to drive ok, like I said it was running hella rich, goes into boost ok when i eas into it but if i punch it, it drops to 0rpm until i let off the gas then it went back to idle.
Parked car in my garage and shut it off.
Tried starting it a few minutes later and wouldn’t start, that’s even when doing the fuel pump trick, it tries to start some times and sometime not.
It seems to start easier when it is not warmed up, I went out last night and it started after a few tries after the fuse pulling to get the fuel out....
It floods the motor enough to not start and when it is running it runs really rich.
Now, when I started it last night I had it at idle and was unplugging sensors to see if anything would happen or not.
Remember, I’m new with Porsches so some sensors I’m unfamiliar with. I downloaded the full service manual and am trying to figure out which ones didn’t change anything when unplugged to see if they are vital to engine running.

my friend, who just got re-stationed to south Carolina, is a VW freak, he owns a supercharged .:R32, Vr6 gti, Toureg, TDI rabbit and a 500hp cabbie.... he is very knowledgeable with VW and most German cars. He said that it sounds like a coolant temp sensor, I looked for it and found a few sensors that look like temp sensors and 2 when unplugged changed nothing..... I am trying to find which sensors these are.....

My question here is what sensors should I check with these symptoms:
Won’t start unless no fuel in system
Running rich all the time
While cool, runs OK but when hot as soon as you touch the gas it bogs badly
No noticeable misfires
Seems to run smooth, remember I’m new to this car so it may not be as smooth as it’s supposed to be.
No check engine light

im open for any input so, please, let me know what you think...

minho78

Start with a new DME Relay. Running rich all the time may be a vaccum leak.
Here's a good resource:
http://www.clarks-garage.com/

Hopefully someone with more knowledge will help out with the symptoms.

fast951

A few things that will cause the engine to run rich (not in any order):

- Incorrect fuel pressure - a bad Fuel Pressure Regulator or incorrect FPR with the chip you have. Check fuel pressure.
- Bad engine temp sensor (under the intake, blue color) - Or damaged wiring to temp sensor
- Damaged injector(s) or injectors harness -
- Bad AFM/MAF
- Bad TPS
- bad O2 sensor (may not be the cause here as the O2 does not come into play for a few seconds after the engine starts).

I would start by checking the eng temp sensor and the fuel pressure. Then go from there!

A vacuum leak will cause your car to run lean at idle. Keep in mind, even if your plugs are saturated with fuel, the engine may not start even if you fix the problem. Get a fresh set of spark plugs.

TheDice951

so why does the temp sensor do so much on german cars? i have been working on cars for almost 10 years and really never messed with german cars till now. i know on my integra the temp sensor doesnt do crap... lol it throws a check engine light but doesnt change the way the engine runs at all.... i thought it was wierd when he told me to check that....

the temp sensor, the blue one, i unpluged while at idle and it wanted to shut off untill i plugged it back in.... so that tells me it is reading something so i will ohm it out to see if it is reading right....

lee101315

You should have around 300 ohms at the water temp sensor at operating temperature

Tom M'Guinn

Might want to pull the vacuum line on the fuel pressure regulator and make sure there is no gas in it. Sometimes with the regulators go bad, they dump fuel into the vacuum system -- nothing but bad things can happen then, including fire.

Spidey944

The temp sensor on all cars lets the PCM know what's going on. When the engine is cold it richens up the fuel mixture, then is starts to lean out when it's warm. If the temp sensor signal is open (unplugged, broken) the PCM will default to full rich mode. It does it that way because if it defaulted to lean mode, engine damage would be more likely to occur.

TheDice951

ok... well when i unplug the temp sensor it tried to die.... so any other ideas? the FPR has no fuel in the lines.... fuel pressure is at 45-50psi, the car has a huntly stage 2 garrett ball bearing turbo and wastegate and fuel pressure regulator, chipped and MAF..... tuned by performance plus... i think thats what its called.... it ran fine until christmas eve..... previous owner was going to work and was on the freeway and got on it to pass a car and when it went into boost its spuddered and poped and smake came out until he came back down.... now it runs rich at idle, when it starts, and drives "ok" until it warms up then i cant give it any gas or it wants to die.....

minho78

I think your fuel pressure regulator is bad. You should be ~29 psi at idle. At least that's what it's showing on mine.

spoolin51

Part it...

TheDice951

part it? lol i dont think so.... well i was looking on all these forums and seem to find that 45psi is the norm for modified 951's... but if im wrong than i will change the fpr.... i have 2 of them on stock one and an ajustable one is that normal?

LUCKYJACKASS

I thought that comment was reserved for Lart!

N-Dub

Tips on where to find a new DME Relay??

minho78

Pelican parts, lindsey racing, and almost any online store that has 944 turbo parts. Also if you live close to carquest they carry it, since they bought worldpac.

TheDice951

i cant figure this crap out... i was trying to do the blink test thing and was reving it up to get the code to pop again, i gave it gas and it started to rev up and then it stop and the the rpms dropped till it died.... i couldnt start it after that... the DME relay was hot so i pulled it and ohmed it... it still seems to be in working order.... but still no start..... i will try again in the morning....

any other ideas?