that is incorrect.

a 92 has only an in tank fuel pump or pumps if you have 2 tanks.

 

I'm not positive a 92 has the pump on the frame, I know my 94 does.

Let me look in the wiring diagram and see if it shows wires feeding a third pump on the 92.

 

your 94 has no fuel pump on the rail.

you may be mistaking the fuel filter for a pump, but i assure you do not have an on rail pump.

89 was last year for on rail pump.

 

Nope, the 92 doesn't have one on the frame from what I can see by the wiring diagram for it in this book.

 

Yes I ascertained that.Could the pump relay be the cause.

 

"your 94 has no fuel pump on the rail."

Yep you're right, haven't been under it in a while and thought it had one but now looking at the wiring I'm must be thinking of a different truck. Must be my 87 that has it.

 

easy to try but the cpu is probably the cause.

i do not have a way to test it but know that the running fuel pump is a sign of a failed one.

 

Thanks a lot for the help.I will try the relay first.If that doesn't do it I will search for a used ecm or ecu whatever the damn thing is.I thought computers were designed for downloading ****.

 

madbob9, are you throwing any codes? You should check your continuous codes first and see if the computer is telling you anything.

Also, you really should go buy the fuel pressure gauge. It costs about $40 I think from most auto parts stores (I got mine from Advance Auto for $40). Then check the pressure. If the pressure at the rail is less than 32-40psi, then you have a problem with your fuel delivery system. Buying a new ECU might be a waste of money. Check your codes and your fuel pressure FIRST.

I am not familiar with your fuel delivery system. From what I understand though, you have a fuel pump in each tank with a check vavle in at least one of the tanks. I imagine that you have a fuel reservoir the the two tnaks feed into (it is normally a plastic cylinder about the size of a large can of vegetables or soup mounted on the frame). The reservoir/selector coudl be gummed up. You oculd have a problem with your fuel pressure regulator, your fuel pump relay, or your other relay (EEC or whatever right next to the FP relay).

But, without measuring the fuel pressure at the rail, you cannot determine whether or not there is a problem in your fuel delivery system. If the pressure in the rail is above atmospheric pressure (like 18psi or something) then gas will spray out when you press the valve stem on the rail. But, the truck will not run if the pressure in the rail is too low.

I do not think that you can assume that the running fuel pump is a symptom of a faulty relay. I think the FP regulator could also cause this problem.

The relays and the regulator are not expensive parts, but if you replace them without checking your pressure and they turn out to have been good, then you will have wasted your time and money. So, before doing anything else, I would strongly urge you to get a fuel pressure tester and just check what the pressure is.

 

To test your fuel pump relay, remove it and apply +12v to the 85 pin and ground the 86 pin, you should hear a CLICK inside. Remove the ground from the 86 and you should hear it CLICK again. If you hear both clicks then your fuel pump relay is working correctly.

I agree that you need to get a fuel pressure gauge to properly see if you have enough pressure at the rail. I would run a liquid filled gauge on the schraeder valve on the rail (liquid filled will prevent the needle from bouncing) while the truck is RUNNING.

 

hahahah .. if you get any luck with your **** downloading ecu for your truck and the problem is solved letme know thanks

 

Well I changed the fp relay with no cure.Checked the fuel pressure,35lbs.And checked everything else with a 2lb hammer,it still wont start.
Could somebody tell me where the ecu is located before I use a 10lb hammer.Thanks

 

the ecu, or computer, is located in engine compartment below and to the out side some. it has the large harness going to it. hard to miss.

you need to loosen the back of the inner plastic fender, unbolt the ecu, after you disconnect the batt., and than 2 bols hold it in. slides straight out.

you need to read the numbers on the box.

subford did not chime in here but like me, he knows that this is probably the problem.

good luck and put the hjammer away for now.

most go to the junkyard and buy the computer, or napa, or a good, not autozone, parts store.

 

im sorry to hijack this thread but can someone tellme why the HECK!! this is happening?

it was taking to long to prime like 1 to 1.30 minutes... ( it would not start after it finished priming)


But today! it only takes 1 second to prime and starts right up ( everything went back to normal ) ... is my truck playing with me or something?

 

in my last post i left out below the brake master cylinder and just towards the fender.

sorry.