Fuel pump keeps running..?

Kemp

Registered User
Well, I've been reading and searching here for years but never posted..so
I have a 90 cougar sc 5spd. Been sitting because of a 'bad fpr' . Changed it. Nothing. You can still hear fuel running by the fpr' loudly. Seems to have good pressure but pump keeps running as long as the key is on, it will not start, I did get it to run on starting fluid. So I pulled fp fuse and got it to run on starting fluid and while it ran I put fuse back in for fp it ran on it's own fuel bit idle was at 2300. It wouldn't idle down and also didn't want to rev over 2700 it would act like it wasn't getting fuel. It seems to flood when you try and start..sensors seem fine..
 
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if fuel is ok, have you checked fuel pressure at test port on fuel rail? you replaced fuel pressure regualtor??? or fuel pump???

i bet you have a major vacuum leak going on some where. or something not connected right.

check faults on car.

starting fluid is a bad idea on fuel injected vehicles, if you make it go pop you can damage all sorts of things.

also is shift light on when vehicle cranks? search for vacuum leaks, many have delt with them..

also check the harmonic balancer for loose or broken.

this is just a start, check the basics first.
 
The way the fuel pump is supposed to work is that with key on (but don't start), the pump runs for a fixed amount of time. This amount of time will run a bunch of fuel through the rail with the regulator bypassing just enough so that around 39psi of fuel pressure is built in the rail. There isn't a pressure sensor in the fuel rail.

If the pump runs continuously, then it indicates a problem with the control system for the fuel pump. If the EEC-IV fails, or if there is a chip (SCT, EEC Tuner, Quarterhorse) on the EEC that fails or isn't fitting right on the J3 port, the fuel pump can run continuously. If the fuel pump relay becomes unreliable, it might stick on.
 
Off hand it sounds like the pump is sucking air - one of the easy checks is the fuel filter...make sure it hasn't been damaged, no leaks, etc.

Has this car ever been hit?

Of course it helps of there is lots of fuel in the tank too :)

I'd start serious checks by putting a fuel gauge on the rail - "seems to have good" is not a good measurement at this point...don't guess - as mentioned, you should see approx. 35 or so psi with key on.
 
Replaced regulator. Checked for vac leaks for the last 3 evenings, all hoses are newer replaced when engine was changed and are all still good. I think it electrical, is the dis module the same as EEC ? When I get home I'll check the relay again. As far as any lights being on there is no check engine, or shift lights on. I took the dis module to get tested but no luck. I tested tps sens and it's good, iacv was replaced but I guess that doesn't mean it's good, can I test this? And how. No mods on this one she's all stock. Fuel at the rail, I haven't put a gauge on it yet. But it sprays out of the valve violently, should be enough hit on the cylinders I would think. It hasn't been in any accidents, but I'll check all that when I get home. Thanks fellas.
 
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fuel pump power is triggered via the EEC which is mounted in the kick panel of the passenger side. The only way the pump can get power is if the fuel pump relay is energized by the EEC or some wire is giving it power directly due to a short.

when working properly, as I said, the EEC-IV will drive the pump for a FIXED amount of time when the key is turned on. After that time has expired the pump will shut off. If your pump is not shutting off, either the EEC-IV thinks the car is running (since if it is running it will run the pump all the time) or something in the control system or wiring has a fault.
 
Well, just got my fuel press gauge. Looks like I'm at 37 lbs key on of course not running. So I listened and checked EEC and it would seem to be crap! Tried an koeo test and it just beeped constantly so I kept waiting for the codes and got nothing. Suggestions? I'm trying to get the car going but also the engine will be used for a cj7 swap. Just want to make sure everything is good while it's in the car as I don't want to do this in the jeep just seems like a better idea.
 
The only way the pump can get power is if the fuel pump relay is energized by the EEC or some wire is giving it power directly due to a short.

But if the relay is stuck in the closed position (which means bad relay) then it would cause the same symptoms wouldn't it? Or does that relay has a constant hot supplying power to it?


Well, just got my fuel press gauge. Looks like I'm at 37 lbs key on of course not running. So I listened and checked EEC and it would seem to be crap! Tried an koeo test and it just beeped constantly so I kept waiting for the codes and got nothing. Suggestions?


Did you use a code scanner or did you "jump" the terminals?
 
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I'm not going to dig the diagram up again as I feel like the op isn't really trying to think this through. But yes, if the relay sticks on, then the pump will run. But I would have hoped the OP would have checked that by now since it's pretty simple and he has gone so far as to replace a fuel pressure regulator, apparently just for the heck of it.

Point is, there are many things that could cause the behavior he is experiencing, and thus far none of the parts he has replaced have anything to do with the behavior he is experiencing, at least as far as what has been reported here.

People need to not just start swapping parts and they need to sit down and think about what is going on, and what might be causing it. Just swapping parts is what gives these cars such bad names. They have lots of parts to swap and they are expensive, when often times the problem doesn't even require a part to be swapped.
 
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