Help,

I posted on the "other" board also.

I need some help quick. I drove the car in to work today and it ran great. Went to start it this evening and it won't start. It turned over fine and fired a little once and then nothing - just cranks.
Car is a 73 2.0 with original fuel injection. I do not hear the fuel pump come on when I turn on the key. I checked and changed the fuse on the relay board. I swapped the relays for the heater blower motor with the fuel pump relay. Still nothing. The heater blower motor does come on. I did try the tip that George Hussey suggests in Tech Tips 700 "remove the top of the fuel pump relay and push the top of the elctromagnet. If the fuel pump operates, the relay board and fuel pump are good" - I could not hear the fuel pump come on when I did this, but it was hard to hear on the street with the traffic.
What now? Looks like I am gonna have to tow it tomorrow (if it is still there!) If it is the fuel pump, what do those usually cost - from a Porsche dealer?

Warrenoliver



Quick update:

I got it going this evening. I hooked up the fuel pump directly to the battery and still nothing so looks like the pump is bad. Then I whacked it a few times with a crescent wrench and it began pumping!
The car started right up after that. I will be very nervous every time I shut it off wondering if it will start again.
Looks like I am in the market for a good used fuel pump.

Warrenoliver

Check the Temp sensor in the head a faulty one will stop your pump. You can always jump the pins in the fuel pump relay with a wire to get it home.

Chappy,

Thanks for the quick response. How would I "jump the pins"? This sure would be easier if it was daylight and/or it was in my garage.

Thanks

Warrenoliver

Hot wire it. A while back the mechanical portion on the ignition switch broke. Hot wired it, it started, and drove away... That was the last thing I did and it should have been the first.

You can at least start there and work your way back. Everything worked except no spark and maybe the fuel pump.

Here is the info you probably need in the 1st portion at the link, fuel injection item.
It breaks the procedure down into clear methods to check the fuel pump.

http://www.rennlist.com/main/areas/services/914_faq.htm

If I were close, I would offer a hand. to get it home and solve the ills

Mike Cooley
Oakfield, TN

Note: the pump only runs for a second or so when you turn the key on. It doesn't start running again until you start the car. This drove me nuts a few years back when I was trying to resurrect a teener that had been sitting many years.

You might try 'cycling' the key switch on and off several times to see if the pump runs briefly when you first hit the key. You can actually hear the pressure building up / pump working harder on each try and the eventual "burp" when the fuel returns to the tank via the return line. I automatically do this to any FI teener (with the pump still in the engine bay) in hot weather to avoid 'vapor lock - start up' embarrasment.

Have you checked the main power supply relay? It provides the power to the coil of the fuel pump relay. If it is not working then you won't get fuel pump and your ecu will be dead.

Is this true? I swear mine stays on even without ever turning the key the rest of the way, but maybe I'm wrong?

True with late model Djet. Ignition on, pump runs for a couple secs then stops. When cranking or running the pump runs constantly of course.

If you turn your ignition on and pump stays running before cranking, something is abnormal.

Steve,
I have not checked the main power supply relay. I assume that is the one on the same relay board as the fuel pump relay. I didn't suspect it being bad since the heater fan runs OK. I just assumed that the main power relay would also power that fan.
I will have to check later today - gotta go to work now.
The car is home now in my garage because I can't find a garage in Madison that wants to tackle it.

Thanks.

Warrenoliver

We all want to know how you got it home....

On the back of a flatbed wrecker. Sorry, no photos of that. The wrecker guy was very good about being careful with the loading and unloading. It required a couple of wooden blocks to help it roll onto the truck bed without scraping the front valence. He even came up with that idea himself! He strapped it down with the wheel straps rather than chains.

Now the real work begins. I need to find out if the fuel pump is dead. I don't know which pins to jumper on the relay board, so I will have to find the wire that powers it and strip it back a bit so I can get power to the wire.

Warrenoliver

Just hook up your fuel line in the engine bay to a pressure gauge. If you don't get pressure then try the other or return line.

It is true for all d-jet that are still wired to factory spec.

Don't know about l-jet. I think they don't run at all until the engine is turning over.

Seems that people who can't find problems on the relay board hard wire their pump to switched 12 volt - usually from the coil. I don't like that practice. The factory design cuts off fuel pressure when the engine is not turning over - like when you have been in an accident an the key is still turned on.

To tell you the truth I had assumed the same thing and couldn't figure out how you could have one without the other. Looked at my relay board diagram and sure enough it is not enabling the heater fan. At least according to the diagram I have.