75 914 starts for a second then quits?

[Howdy123456]

I was happily driving home from work when it just died. It starts for about two-three seconds then quits out again. I am working through the electrical checks(fuel pump works) in my haynes manual but was hoping to get to the answer faster. I have fresh gas as well and I dove it to work that morning and it was fine.Any help would be greatly appreciated. and if this is already posted just let me know the link - Thanks.

[MarKoBrow]

Unplug the airflow meter and see if it starts, I am assuming that you checked for spark, fuel ect...?

[RandyLok]

Is it a 1.8 or 2.0? (Just asking so we follow the correct troubleshooting path for Ljet vs. Djet.)

[Howdy123456]

Its a 1.8 - I checked the air flow pot with a vom per the haynes manual I have as well as the fuel pressure,throttle switch, and of course the fuel pump. I checked all vacuum hoses and wiring other than the control unit - ran out of daylight =) They all checked out good so far. I havent gotten into the ignition or spark checks because it runs ok for a few seconds but that may be the next step. I did try it with the air flow sensor unplugged and still no luck. I may also try to run the fuel pump directly from the a can for a test bypassing the filter to see if that may be plugged but the pressure at the injectors looks good. I am really a bit confused but learning a lot. Again any help is greatly welcomed.
Thanks in advance. Bryan

[Howdy123456]

I am still having no luck getting this running for more than a few seconds. The fuel pump starts when the starter is running but as soon as it shuts off the fuel pump shuts off. I am also under the impression that when the key is turned on and I move the air flow flapper of its switch the fuel pump should also start. (it doesn't) Is this a correct assumption? Either way I am still stuck and need some help - its still confusing me.

Thanks for the help in advance.
Bryan

[Dave at Pelican Parts]

You are correct that the pump should run any time the key is on and the vane in the AFM is moved. So it sounds like you have a wiring problem or an AFM problem. The AFM will connect two of the wires that go to it when the vane opens. Figure out which ones (the wiring diagram will actually tell you if you look at it enough) and check to see if that actually does happen.

--DD

[Tobra]

You may have bad air flow meter too. The impedence(resistance) should change when door in AFM moves. Rebuilt units are available, though they are from VW applications(bug/bus)

[Howdy123456]

I did check the AFM with my VOM and it was with in spec for the manual I have(for the pot). I need to check the contact that turns on the pump however and trace that back through the system. I will get to look at it again this weekend or tonight hopefully and trace the wiring out a bit more and see if I can get to the root cause. I have a two relay block that is not attached to any thing lying in the engine bay by the battery and I think one relay might be the fuel relay but I also have the relay board in the front left of the engine bay with another relay in it - all the other spots are empty on it - All I need to do now is figure out the electrical drawings. Thanks again for the help.

[mshuard]

I had a similar issue... Same engine, and the fuel pump would not run when the key was on and the air flow flap was open. It SHOULD run when the flap is open, and shut off when the flap is closed, as the control unit would assume the car was stalled or intentionally shut down.

I did the same trouble shooting steps you have done, and it turned out to be the double relay that is screwed onto the battery tray. I too had an almost empty relay board, even though one of the relay slots was for a fuel pump??

It was pretty strange in my case, as I had two of the same double relays under the hood. 1 was in use, and plugged in, but was just lying on the engine. The original was still screwed onto the bat tray. I took a wild stab at trying the original after referencing a Haynes manual. IT WORKED!! The fuel pump resumed normal operation with the flap open...

Anyway, if it was me, I would try to test the double relay that is screwed to the battery tray. Mine had two seperate plugs going to it. One was black and one was white. just for reference...

Try googling how to test a relay.. Its pretty simple really, but you need a volt ohm meter that tests continuity as well as a 12 volt battery...

Test both sides of the relay! Also, I haven't checked yet, but the double relay could be two relays of the same type in one case. It could be that one went bad and the other is good. You could check to see if the plug type was the same for both sides and switch the plugs... ???

Good luck, and let me know how it goes!

[Howdy123456]

Thanks for the advice - thats exactly where I am at. I am an industrial electrician so the electrical checks and realy checks are no issue for me but reading the haynes manual drawings are challenging - lol. Also as I went through the box of parts the gent gave me who sold it to me they are all fuel system parts and relay's - hmm something he didnt tell me maybe? haha. Either way I will post an update in the morning and am very grateful for this forum and everyone's advice - Thanks!!!

[Howdy123456]

WOOOHOOO - It was the double relay - the right side realy coil is bad as you mount it. You all are fantastic thanks for the advice!!! How often do these things fail? should I be carring a few spares with me? I believe this was a newer one as well that failed as I put a older bosch metal dual relay back in (it tested ok) and mounted it correctly to the battery tray for grounding. I am tempted on just buying some ice cube relay's from allen bradley - cheaper and have a visual indication of operation as well as the amount of open and closed contacts needed- thoughts?

Again thanks so much - I think my wife was ready to kill me! haha

[Tobra]

relays don't fail often, pretty simple. Lot of relays and fuses on a 914 can be used in more than one place. Double relay does not go too often, but they are getting old now. Can you get one new, if not too $$$ not a bad idea to carry one, not like you are getting it at kragen or pep boys. I am going to buy a new fuel pump and mount it like they did for the later cars when I put in the SS fuel lines, just because it is old as dirt

[trekkor]

My first 914 had a 1.8 and took an adjustment of the AFM flap to keep it running.
You can take the plastic cover off and have a helpper hold it open a little bit while cranking.

I suspect you have a massive vacuum leak. The 1.8 will not run if the oil filler cap is off or if it has a broken gasket seal.


KT

[glennholmes]

check pump relays and fuse in engine comp