dies once...and only once.

[Spitfire1975]

Ok. Got an 86 ranger....2.9...When you start the truck when cold, it runs for about 5 minutes and then dies. No sputtering, coughing, wheezing......just flat out dies as if someone turned off the ignition. Will NOT start again. Let it sit for about 20 minutes and fires right back up. Runs great, no problems again whatsoever. You can drive it all day long with no issues.

What could cause this? TFI? I replaced the Fuel Pump (used). Fuel Filter is new. Coolant Temperature Sensor is new. Air Temperature Sensor is new(er). TPS is set where it needs to be and tests ok. NO CODES ARE BEING THROWN. Just gave it new cap, rotor, plugs, wires, Sea Foamed the intake, changed ALL fluids, belts and hoses. Mileage is 167,000.

When it is running it runs beautifully.

 

[IMenriched]

Ok. Got an 86 ranger....2.9...When you start the truck when cold, it runs for about 5 minutes and then dies. No sputtering, coughing, wheezing......just flat out dies as if someone turned off the ignition. Will NOT start again. Let it sit for about 20 minutes and fires right back up. Runs great, no problems again whatsoever. You can drive it all day long with no issues.

What could cause this? TFI? I replaced the Fuel Pump (used). Fuel Filter is new. Coolant Temperature Sensor is new. Air Temperature Sensor is new(er). TPS is set where it needs to be and tests ok. NO CODES ARE BEING THROWN. Just gave it new cap, rotor, plugs, wires, Sea Foamed the intake, changed ALL fluids, belts and hoses. Mileage is 167,000.

When it is running it runs beautifully.

Classic TFI symptoms... but usually with that you consistently , or nearly so, get the 20 min barrier.

It might be signs of a failing fuel pump.
after it dies is there a bunch of air in the fuel manifold?? press the shraider valve...does it stream a nice steady stream of gas?? or spray a mist?

mist hints of a bad in tank pump.
or...it could be the main fuel pump on the frame rail with bad check valve too.

more cheaper route is to double check those grounds and connections and,
Has the relay hasn't been replaced...might want to consider that to

 

[Spitfire1975]

Two of the relays have been replaced and have the same part number. the one with the black top is the only one still original. The fuel pump was a used replacement that had 115,000 miles on it. No air in the rail, but was not "shooting" out like you would expect it to when depressing the shrader, just a quick "blurp." Pressure when KOEO is about 36 lbs with one cycle of the pump. Running pressure drops to 30 (the other pump was the same, so I am not trusting my Harbor Freight Fuel Pressure tester too much).

All of the grounds seem to be pretty good. Even took a couple off and sanded/electrical greased them.

Running it again right now. Been on for almost twenty minutes.........no dying.


It is making a weird noise though......will start a different thread for that issue.

 

[IMenriched]

Two of the relays have been replaced and have the same part number. the one with the black top is the only one still original. The fuel pump was a used replacement that had 115,000 miles on it. No air in the rail, but was not "shooting" out like you would expect it to when depressing the shrader, just a quick "blurp." Pressure when KOEO is about 36 lbs with one cycle of the pump. Running pressure drops to 30 (the other pump was the same, so I am not trusting my Harbor Freight Fuel Pressure tester too much).

All of the grounds seem to be pretty good. Even took a couple off and sanded/electrical greased them.

Running it again right now. Been on for almost twenty minutes.........no dying.


It is making a weird noise though......will start a different thread for that issue.

what happened to the pressure after you shut the engine off?

what does the pressure do if you goose the throttle while its running??
does pressure increase or decrease??

 

[Spitfire1975]

Engine off....pressure goes up initially a couple of pounds and then starts to drop off slowly.

Pressure when goosing stays right around the 30 lbs.

 

[IMenriched]

Engine off....pressure goes up initially a couple of pounds and then starts to drop off slowly.

Pressure when goosing stays right around the 30 lbs.

well... dropping pressure is leading to a bad check valve in the main fuel pump (on the frame rail). the pressure should stay steady after the engine is shut off

 

[Spitfire1975]

Would a bad check valve cause the run, die and no start for twenty minutes? Is 5 minutes of idling be enough to overheat the pump?

Plus, it has done it now with two different pumps. (not saying that both pumps couldn't be bad)

 

[IMenriched]

Would a bad check valve cause the run, die and no start for twenty minutes? Is 5 minutes of idling be enough to overheat the pump?

Plus, it has done it now with two different pumps. (not saying that both pumps couldn't be bad)

Understand what your saying....reconsidering my thought line.
how does it start(cold)? do you need to crank on it several seconds? or...does it fire right up? and run fine? no missing or running rough.


usually if the check valve is bad , one would gets a hard start, lots of cranking. and couple of restarts before it smooths out...depending on the severity of check valve and condition of the fuel pump. you seem to not have this condition. true?

you might have a sloppy connection on a fuel line....where it draws a bit of air when off. it starts...but doesn't quite seal up when restarted...dies then weep a bit of gas reseals and then your golden.....just a thought

still couldn't hurt to get the TFI checked...

 

[Spitfire1975]

you might have a sloppy connection on a fuel line....where it draws a bit of air when off. it starts...but doesn't quite seal up when restarted...dies then weep a bit of gas reseals and then your golden.....just a thought

AAAHHHHH!!! This I did not think of! I have obviously been messing with the pump. Had to get new retaining clips for it even. Thank you. I will mess with it a little more later and see whats going on down there. If the connection is loose, it may explain the pressure loss?

Starts cold runs fine no problems, until it dies. And it did not even die when I tried it yesterday.

 

[Spitfire1975]

I have not been able to get the problem to occur again. Maybe the problem was originally a bad fuel pump and then loose fuel line connection that has now sealed back up?

Either way, it seems to be good. Keeping my fingers crossed!

And just in case, I have a couple of TFI's in the glove box.

 

[96Greenster]

Classic TFI symptoms... but usually with that you consistently , or nearly so, get the 20 min barrier.

It might be signs of a failing fuel pump.
after it dies is there a bunch of air in the fuel manifold?? press the shraider valve...does it stream a nice steady stream of gas?? or spray a mist?

mist hints of a bad in tank pump.
or...it could be the main fuel pump on the frame rail with bad check valve too.

more cheaper route is to double check those grounds and connections and,
Has the relay hasn't been replaced...might want to consider that to

DOnt mean to hijack thread but, Imenriched u said air in fuel rail? I was stranded on side of road one time, and when pressed the valve on the fuel rail it mostly was air with little squirt.. Was does that mean?? Pump going bad? Hasnt done it in a couple of days.. Oh btw that day was hot outside, if has to do anything . And sorry again for Hijacking

 

[Spitfire1975]

If your hijacking gets me more information about something, then it's all good.

 

[IMenriched]

DOnt mean to hijack thread but, Imenriched u said air in fuel rail? I was stranded on side of road one time, and when pressed the valve on the fuel rail it mostly was air with little squirt.. Was does that mean?? Pump going bad? Hasnt done it in a couple of days.. Oh btw that day was hot outside, if has to do anything . And sorry again for Hijacking

From what I've seen...yes it leads to a bad in-tank fuel pump. In my 86' the rubber hose that couples the in-tank pump to the rest of the assembly was gone...the pump still worked. but with age against it, I replaced the whole thing.

It could also mean a restriction in the fuel system. Even the return side.

Not sure what year unit you experienced this in....with gen 1 & 2 we didn't have the alcohol blended fuels we have today, especially like in the upper midwest. With age adding on, combined with the alcohol blended fuels, the o-rings that seal the slip joints/ quick disconnects of the fuel system,(fuel filters & FPR), of these units may draw air after awhile, making the fuel pumps work harder. Like the situation you had on very hot days.

so look things over closely

 

[96Greenster]

Cool thanx

 

[Spitfire1975]

Well, so far so good. I think I am going to be able to attribute the "problem" to me jacking around with the truck. Good.