Fuel pump relay.

[jiggity76]

Not hearing the fuel pump kick on when I tried starting the 89 Cutlass International the other day.  The owner said it was running a couple of weeks ago, but then started to die after a few seconds.  Thought maybe it was the relay and was wondering where to find it.  I assume it's on the drivers side strut tower maybe? 

[Padgett]

Runs for a few seconds then dies sounds more like a bad oil pressure switch. There should be a loose wire with a green connector (not sure where in a Cutlass) that is a direct connection to the fuel pump. Can either test for 12v there or apply 12v and see if the fuel pump starts (may be able to hear or see on rail pressure gauge).

[jiggity76]

Thanks for the reply!  I'm going to buy both the pump relay and the oil switch since they are pretty cheap.  The only way to get it started is by spraying starter fluid into the air tube into the manifold and then it dies when you stop so definitely not getting fuel somewhere.  I had the guy I bought it from turn the power on while I listened for the pump but didn't hear anything at all, so pump is either out or not getting any signal from the two sources you listed.  Just want to get it started so I can load it on the trailer,  would be a lot easier.

[Imp558]

That one should power the fuel pump through the relay and switch in parallel meaning that if only one is bad it should still be on. First gen w-bodies suffer from insufficient wire gauge to the fuel pump. It was a good enough gauge when the car was new but as the crimps and all age it can be a problem.

Try jumping past the FP relay and see if that works, if so it's the relay or circuit to the pump. If it doesn't then it's the pump.

A pressure gauge would make for a nice tool to have now too.

[jiggity76]

Ok, thanks.  I will have to play around with it in a couple of weeks.  I'd thought I would try the relay since it's cheap and out in the open.  If that's not it, then I'll check the wire like you said and if that's good then it's probably the pump.  Car has sat since 09 so maybe the pump went out?  The car ran a couple of weeks ago said the owner.  He drove it from the storage barn to his house not very far away and it ran and started fine.  Could old gas or crap in the tank plug the filter or kill the pump?

[Imp558]

yes, if he ran 7 year old gas it could have plugged anything, including the injectors. The FP Relay is probably fine.

[jiggity76]

Ok, might have to get it home first and then start diagnosing it from there.  Thanks for your help!

[Padgett]

Well you have a choice: either instrument it properly (fuel pressure on fuel rail and DMM on the prime wire (with green connector under hood USU on driver's side - used at the factory to prime the fuel system) or just throw parts at it until you either go broke or junk it.

[Imp558]

A multimeter may show good power unless you tested at the rear of the car and with a good load on it, for instance - the fuel pump.

Edited July 26, 2016 by Imp558

[Schurkey]

1.  If the pump runs for two seconds when the key is first turned "on" then the pump quits, there's nothing wrong with the relay.  The relay is doing it's job--running the pump as long as it's getting a command signal from the ECM.

 

2.  If the pump runs for two seconds, the wiring to the pump cannot be open or otherwise completely failed.  The wiring may be wounded, however.

 

3.  If the pump runs for two seconds then quits, that tells you NOTHING about the oil pressure switch.  Two seconds of engine cranking/running may not be enough to build oil pressure at the switch to keep the pump running.

 

4.  If the engine runs on supplemental fuel, but the pump DOESN'T run, the entire fuel system including the ECM and wiring harness is suspect.

 

 

 

 

I envy the hearing ability of the rest of you.  I have never, ever, not once heard the fuel pumps in any of my vehicles from the driver's seat.  (Ok, two exceptions:  I had an engine-driven pump fail so that it sounded like a rod knock; and I have an aftermarket Holley hot-rod pump that I could hear from a block away.  OEM-style in-tank electric pumps...NO.)

[Imp558]

I can hear most any in-tank pumps from the drivers seat without the engine running.

[jiggity76]

Thanks for the scenarios guys.  Once I get it home, I can investigate it more and zero in on what's the cause.  Scenario #4 is what I remember it doing but not completely sure.  My gut tells me to just have it diagnosed at the garage and that way I'm not replacing unnecessary parts/wasting money and getting myself worked up.  That way if it's something that I can handle, I can then replace or repair it myself.  Definitely not junking the car as of now and I have deep pockets for my projects.  I haven't like new vehicles for a long time and don't want to have what everyone else is driving.  Love everything 80's - cars, movies and music!

[GabsOlds]

Update? 

[jiggity76]

I've been working on getting my 87 GMC Sierra together so haven't worked on it.  Also, the rust is a lot worse on the car than I thought originally so I think I'm going to just put it away and use it as a parts car for my 91.  Most of the main frame rails, body supports, and engine cradle are full of holes, crusty so I don't think it's safe anymore.  The mounts where the trailing arms are attached are really weak too.

[GabsOlds]

Another one bites the dust! Sad ! 

[Imp558]

Even worse being an International. Sorry to hear this....

[jiggity76]

Me too, really sucks.  These are getting harder to find and especially one from the original owner with all the documentation and window sticker.  That's why I hate the winter road salt around here so bad.