82-T/A

Hey guys!

Well, I've got a 1984 Porsche 944 that I bought NOT running. It needs a few things to get it back on the road, but I just got it started today! I replaced the starter, and the DME relay. I was able to get the car started by using starting fluid. The car would run for a few seconds and then it would eventually die. I think I had it runing about 30 seconds at one point.

I replaced the DME Relay thinking that was my problem, but the car still doesn't run. I am thinking that maybe the fuel pump is bad (or not getting any juice).

I found a port at the front of the fuel rail, so I removed it thinking that I would get a fuel spurt. (I figured the fuel pump would have pressurized the rail). All that I got was maybe a couple of drops that came out.

Any idea what else I should check? What can I expect to pay for a fuel pump for my 944? How hard is it to replace? In my 87 Fiero, I have to lift the entire car off the ground and drop the tank which is right in the middle of the car (pain in the butt!!!).


Thanks guys!!!


Todd,
2006 Pontiac Solstice
2002 Ford Crown Victoria LX
1987 Pontiac Fiero SE / V6 5-Speed
1984 Pontiac Fiero 2m4 SE WS6
1984 Porsche 944 5-Speed
1981 Pontiac TransAm WS6 (Olds 455)
1973 Volkswagen Type-2 Transporter

cgoldhill

By the port do you mean one of the fuel lines connected to the rail? Sounds like you've got a fuel leak somewhere thats makin all of the fuel depressurize to let air in and drain all the gas out of the rail. It might be big enough where you can't get it to start on its own. I'd think that youd notice something like that though as the fuel pump would be tryin to throw alot of gas out and youd smell it so your fuel pump might be fubar as well. The leak might be in the pump itself, i suppose. Check to see if you get gas while cranking it. Go to www.clarks-garage.com. There is probably the best online troubleshooting guide on the internet at that site. Go around to pelicanparts.com, vertexauto.com, 944online.com for fuel pump prices. I also use importec.com for some of the the generic oem parts. Vertex and importec have good prices.

82-T/A

Thanks ghill,

Well, on the very front of the fuel rail, there is a 19mm cap. The plastic cover has a notch in it that allows you to pull it back, and it exposes that 19mm cap. I removed that cap, and then turned the ignition on, and then off to see if fuel would spurt out (I had a towel under it). Nothing came out AT ALL.

I AM getting spark though... which makes me wonder...

I'm not overly familiar with this type of car, so what I'd like to know is, does the computer in this Porsche ALSO control the spark timing? I'm worried that maybe the ECM is dead. However, if the ECM does in fact control spark timing, then that would tell me that my ECM is in fact good (because I'm getting spark), and then I'd know that it was merely an issue with fuel.

I'm thinking that both fuel pumps might be bad. I know that in most cars I have which have fuel injection, the pump(s) will pressurize right when you turn the car to the on position (even before starting it). This typically gets the car ready for starting. I don't hear anything, so I don't believe it's a blockage.

I'm reluctant to replace the pumps unless I know that in fact that is the problem. How can I test them?


Thanks!!!

striker

i have a later year 85 i also have starting problems. if you are wanting to test your fuel pump you can take out your DME relays and jump 30 to 87b. i thought this was the problem with mine also but when hotwired to bypass the computer it comes on. unlike your problem though when i take the cap off the end of the fuel rail and turn the engine over i am getting fuel comming out. i have replaced the DME, refrence sensors, and several other things now im leaning towards the computer because i am not getting spark untill i let go of the key.

dmilzoff

The DME will not allow the fuel pump to start until a minimum 400 rpm is found at the reference sensor. The DME will also not provide spark until the same 400 rpm. If you are getting spark (the car started for a short time with starter fluid) the Reference Sensor and DME Relay is probably OK. I would check the wiring to the fuel pump (see if the pump is getting voltage) DURING ignition. If no voltage, it may be the DME. If the pump is getting voltage, it may be the pump or a blocked fuel line or fuel filter.

smac951

i'd check the fuel filter.

82-T/A

Thanks for all of the advice guys!!!

Here is the update...


I replaced the DME relay anyway since I purchased one before and it still didn't do the trick. I was ready to go buy a new fuel pump, but decided I would try one more thing. I actually ran a wire from the positive lead on the fuel pump in through one of the drain holes, all the way to the front of the car and wired it up directly to the battery with a switch (ONLY temporarily). I was actually able to get the car to run! I drove it around the cul-de-sac and briefly in my neighborhood and I have verified that the clutch and everything else works well. It ran REALLY badly at first, so I put three gallons of high octane fuel in it, along with some octane booster to help the old fuel that was already in there.

I also changed out the spark plugs, plug wires, oil filter, fuel filter, and the air filter and it runs much much better right now. It does have a very noticable hesitation on acceleration. I believe this has something to do with that air meter valve (or whatever it's called) in the air intake path. Is there anything else you guys think might cause this?

I'm inclined to think the fuel pump not running has to do with that security system box that's in the passenger side footwell (not sure what it's called). With this temporary wire I hooked up, I should be able to test to find out where the buck stops.

Other than that, it's coming along nicely.

I have a bunch of new interior pieces that I'm planning on putting in. I just need to replace the carpet first. But, before I do that, I've got to change out the gaskets. It leaks when it's outside and it rains.

944Cup

Latest edition of 9 Magazine has a simple test for checking the fuel pump and replacement instructions if need be.

Free download: http://www.9magazine.com/issue241206.html