Fuel Pump Keeps Running. Welcome Any Advice!!!
 

When i turn the key the fuel pump primes like it should. But it keeps running.
I recently replaced the fuel filter and i dont see leekage anywhere.

I have already replaced the fuel pump regulator. I am stuck in the real sense.

Someone at the parts store mentioned a fusable link and fuel pump relay switch????

I am all ears and appreciate any help i can get to get on the road again.

thanks,
mark

Re: Fuel Pump Keeps Running. Welcome Any Advice!!!
 

I'm confused. You're turning the key ON. The fuel pump is supposed to turn on. Why would it shut off?

Re: Fuel Pump Keeps Running. Welcome Any Advice!!!
 

Normally it runs two times for 1-2 seconds each to prime the system, then it doesn't do anything else until it senses a signal from the distributor.

Does it stop running if you disconnect the TFI module? Lots of causes, seems to be kind of common; but very hard to pin point the specific cause. Honestly, if it's turning off when the key is off, and it runs OK, I would probably just leave it be. There isn't anything that's monitoring your fuel pressure, the priming function is static - so it's not going to be anything in your fuel system. It's going to be something electronic.

If fuse-able link were the cause, it wouldn't work at all.

If it were the relay, then it would run all of the time when the key was off.

I suppose you computer could be grounding the fuel pump relay all of the time (the computer is what controls your fuel pump operation), or you simply could have a short in the control wire between the relay and computer. You might be able to test that theory at the diagnostic connector as it has a fuel pump test - the test is the act of ground the control wire to run the pumps all the time to diagnose fuel pump circuit problems.

Re: Fuel Pump Keeps Running. Welcome Any Advice!!!
 

Oh duh. I see what he's saying now. That is kind of odd. But its better than breaking the other way around and not working at all!

Re: Fuel Pump Keeps Running. Welcome Any Advice!!!
 

It runs terrible. backfiring and won't pull a hill. hardly idles and kinda stuck at work with it right now.
I don't even know what a TFI but i have done mechanic work and have a multi tester. I will start step by step on your comments.

I really appreciate input cause i am unfamiliar with this electronic set up on this truck.

is there a diagram around that could help someone like me chase these things down.

Re: Fuel Pump Keeps Running. Welcome Any Advice!!!
 

Best is EVTM from Helm Inc, it's what they use at the dealerships, they will copy pages for you for free, or the manual is around $30 - Ebay has them used for decent price usually. Or All Data DIY. Autozone has repair guides and the diagrams (similar to those in Chiltons or Hayes, which are somewhat unreliable) can be found under the Chassis Electrical / Wiring Diagrams section, but you would need to register an account.

86 doesn't have a functioning check engine light either, would be worth while to see if you have any codes present to help with diagnostics.

Re: Fuel Pump Keeps Running. Welcome Any Advice!!!
 

think i found the TFI. plugs into the distributor just below the cap. there are two more electrical unions to the front of the distributor but the TFI plugs directly to it as i understand it.

Unplugged it turned the key and the pump ran and did not shut off.

Fuel Pump Keeps Running. What is up?
 

my fuel pump keeps running after the normal 'priming period'.

on advice from another thread- disconnected the TFI and the pump still runs continously when i turn the key.

have no idea how to chase the problem down and loving any advice to get me on the road again.

1986 Ranger 4wd XLT 2.9

Re: Fuel Pump Keeps Running. What is up?
 

Regulator not maintaining pressure at the fuel rail and letting everything go back down the return line perhaps.


Wait why did you start a new thread?
http://www.fordrangerforum.com/2-9-l...ny-advice.html

Re: Fuel Pump Keeps Running. What is up?
 

thanks for input.
i replaced the fuel pump regulator which is located under the hood.
advice to me is that it is electrial in nature.

I obviously don't know though.

----------

new thread different forum same topic.

is that appropriate?

i am desperate with lack of knowledge on this truck prob.

Re: Fuel Pump Keeps Running. What is up?
 

Fuel pumps just run at a constant speed when they get power. There is something that powers them up when you turn the key into the run position for a fixed three second interval only, and then either the same or a separate power wire is energized with continual power when the engine is actually running.
I don't know what controls those two scenarios. I'd say it's a relay that controls this action. But the fuel pump relay is just an ordinary relay so ... ???

Re: Fuel Pump Keeps Running. What is up?
 

pull the relay and see what happens. maybe the relay is bad and is sticking closed.


give that a shot and start from there.

Re: Fuel Pump Keeps Running. What is up?
 

cool, let me look for that thing.

Re: Fuel Pump Keeps Running. What is up?
 

DW.

i was just at autozone and was going to get a relay incase this one is bad and at least i could see what it looks like.

i was told it does not have a relay.

Re: Fuel Pump Keeps Running. What is up?
 

attached is an image as per mitchell ondemand.

according to mitchell your truck does have a fuel pump relay assuming it is EFI and not carbureted. The same image is used for the 2.3 and the 2.9.