Yabo

I turn the key, to the second click where the fuel pump turns on.

i turn off the key. ! light comes on, and fuel pump stays on. i cant seem to do anything to turn it off, unless i turn the key , turn over, or start the car for a second, then turn it off. then its fine till next time i do the same sequence...?

i guess ill combine a similar question... my fuel pump doenst stop humming if i just leave the key in the second position. is that normal? or is it supposed to shut off after a few seconds? i know on my range rover the fuel pump comes on at the second click, and then turns off in about 4 or 5 seconds, maybe less...

can anyone give me some advice on this?

SoCal Driver

Interesting. Heard of this happening. Since the second set of contacts in the DME relay is closed by the DME it would seem that something in the DME is at fault. Should stop if the key is turned totally off and/or removed. Then are you sure it's the fuel pump and not the little fan in the AC temp control by the glovebox?

I would also speculate that an aftermarket alarm or stereo system may be wired in wrong to the bottom of the fuse/relay board.

Yabo

first of all, i have no clue if i have an alarm. i'm 99 percent sure it is the fuel pump, as it is coming from the rear of the car. So it coudlnt be the relay? it would have to be the dme itself... i do have a little light at the left of the steering wheel in the dash next to the headlight switch.. it llooks like it would be red if it lit up. would this be a factory alarm? is there anything i could check on that?

im confused here,

SoCal Driver

The two previous threads I've read on this tend to pass it off as "just happens". I'm inclinded to think that this is a potential problem when coupled with an gas leak. The fuel pump is not supposed to stay on if the engine isn't rpm'ing.

I would test wither it's the DME realy by swapping it out with a known good relay. If the fuel pump stays on the same as before then I would start looking at an alarm or an after market stereo install.

If it's the relay it may be the diode that you can see on the circuit board. Read a while back that someone found this blown. Don't know if the fuel pump stayed on.

Have you swapped in a different year engine?

Yabo

nope, as far as i know, same year engine. so are you saying that typically, if you turn the key to the second position, and leave it there, the fuel pump should turn off there too after a certtain amount of time?

i'm not relaly worried, since i can get it to go off, just like to not have these little problems, for if say, someone else was using the car, it would be a pain

SoCal Driver

Fuel pump should never come on unless you are cranking the car. Even then it should stay on only a half second or so after you stop cranking when the engine does not start. The speed and reference sensor input to the DME keeps the fuel pump on while the engine is running. Speculated that there is a 200 to 300 rpm lower limit to keeping the fuel pump running.

About the only way I can see this occuring is if the DME is bad or the wiring under the relays got switched around. Driveable but not a good thing.

Yabo

i'm not so sure you are correct on this. on all other cars i have .. 2000 volvo v70r, range rover, volvo 740 wagon, the fuel pump comes on on second click of key, to get gas pressure to the rail before cranking begins. i dont see why this car would be different.

Yabo

and unless you have a leak, i don't see why it would be detrimental to anything, except maybe putting strain on the fuel pump, or pushing fuel past leaky injectors.

Oddjob

Certainly try the DME relay first.

Any possibility of a short in the ignition switch itself?

I have a had somewhat of a different problem along the same lines. When I turn the key to the 2nd position, the fuel injectors start squirting. I have swapped the DME and ignition relays and also swapped the speed ref. sensor. Next Im going to swap the ignition switch, then test the DME itself, and if that doesnt work I will blow up the car....

Good luck.

SoCal Driver

Guess you must be the expert on this. I'll have to get out my factory manuals and change them.

Yabo

no, im nto telling you you are wrong. but this is just what it is on all cars in my experienc.e i was just double checking you. no reason to be sarcastic.

Bryan

The 944 does things differently. The fuel pump should NOT run with the key in position two. The ECU turns the fuel pump on when you crank the engine and it sees a signal from the engine speed sensor. SoCal's got it right.

This sounds to me like a previous owner or mechanic was trying to fix a no-start problem and thought that the fuel pump should run with the key in position 2 (like many other cars do) and commenced to make some modifications. Or, possibly the ignition switch is having a problem but this theory is definitely in second place.

Are you sure it's just the "!" or is it every warning light in the cluster? I bet every warning light in the cluster comes on when you shut the key off. This means that the ECU is getting 12V all the time, and when you shut the engine off, the ECU is still powered up but the engine speed signal is gone. This tells the ECU to do the "bulb check" thing - illuminate all the warning lights. Because to the ECU, key position 2 but no engine speed means you're about to start the engine so time to do bulb check.

I bet further investigation will reveal some hokey "repair" that is resulting in constant 12V to the ECU.

Bryan

Yabo

hmm. where should i start? anyone got any good ideas of where to start testing voltages and such

Yabo

Well, figured otu somewhat what it is. I went out wiht my dad and looked at it. we flicked the relay a few times. turned the key to the second click, fuel pump came on like it always has for me, and turned off the key and the fuel pump shut off now. so must be a flaky relay. Still doesnt' explain why the fuel pump runs at second click. And i guess teh ! light was a different thing in itself. I have my alternator belt off, and my ac compressor not mounted because im fixing the mount.. and i was going to take the alternator off, but didnt end up, so i hadn't reattached the wires to the back of teh alternator, which caused the light to stay on even with key out... i guess. Seems supid to me that the car should worry about its alternator not being hooked up even with the key out.. but as i said before, if i start it quick and shut it down, the light doesnt stay on with the key out. oh well. ill try my new relay when it comes in to see if thats why it turns on second click.

looked at the wiring diagram.. what is with the power wire from the ac compressor to the fuel pump? or thats what it looks like anyway.
Thanks for the help