I've got a cranky plow truck, 1989 f250 5.8 dual tank (I only use the rear) standard trans.

Truck has had a rough life, but has never failed to start / idle / run fine for me

Now recently, truck will start, idle fine for anywhere between about a minute to about two minutes, then die - sounds and acts like it's running out of gas, to me, and will sputter a little if you play the accelerator before dying. After another 5 minutes or so, will start / idle and run fine - for about another minute.

I changed the fuel filter, and swapped out the fuel pressure regulator, and I changed out the fuel pump relay - no change. Yes, I should pull codes, but the truck usually has codes popping up all the time, I can't keep up with them (it's a plow truck). I can try to figure out how to pull codes, if that's absolutely necessary, but I'm wondering if my symptoms ring a bell to anyone out there, and perhaps a kindly soul can point me in the right direction..

Thanks in advance!

 

Somthing is getting too hot then it dies...cools off, starts, etc...?? Not sure thats weird. Everything else work fine? Everything electrical works good?

 

To find out for sure if it is a fuel problem put a gauge on the fuel manifold and check the fuel pressure with it not running and pin #6 of the Test Connector grounded with the key on. Should be about 45 PSI.

But I think you will find that it is more than likely the TFI module on the side of the distributor.

The Test connector:
http://i54.photobucket.com/albums/g9...taLinkConn.jpg

 

My guess is the IAC valve (idle air control). Clean the IAC valve on the side of the throttle body. Remove it, clean out the carbon deposits with carb / choke cleaner. Re-install with a new gasket if needed. I had the same type of issue with my 91 E150 5.8, cleaned the IAC and no more issue.

 

You can get a code reader from Schucks for about $30.00. Go to www.schucks.com and check out their code readers. My local Schucks wanted $40.00 for one and I told them that it was on line for $30.00 They told me to bring in the print out and they would match it. You need to know the codes before you start throwing money at it. Hope this helps, gr

 

go to www.fordfeulinjection.com. They have a section explaining how to do a self test without scanners, code readers etc. Just have to have a good eye and attention span to watch the flashes of the check engine light. I dont, did the test once and said to hell with that and borrowed a friend of my dads snap on scanner.

 

Thanks all, I'll try all checks and fixes you've listed - I didn't think to check the IAC valve, and I'll try to pull codes, too.

 

86rustbucket, you claim you had the same type of problem - remedied by the IAC clean and reinstall - did your truck run fine for about 1min then die completely? repeadedly? My next try was going to be the TP sensor, but if you claim the same symptoms as me, I'll try the IAC - Thanks

 

PULL codes and stop guessing. thats what they are there for.

 

Cleaning the IAC isn't a bad idea because even if it's the problem it won't throw a code. Kem is right though - before you spend any money on it, pull the codes. Auto repair is 100 times easier when it's not a guessing game.

 

89F250, yes, it would run, sputter and then die. It would start again after it died, and then run and sputter again. Cleaning the IAC is pretty easy also and was recommended in the Haynes manual for my van, that is why I tried it, although it is harder on a van than on a truck.

Kemicalburns, it has been awhile, but I don't think that the dirty IAC showed up on the code scanner when I had this problem... but as I get older, my memory isn't what it used to be...

 

Still working this one....my progress so far has been to pull codes (code 11 key off, followed by a 33 running) but most interesting is the fuel press gage readings - pump(s) will pressurize fuel rail to ~32psi before start (too low, Subford??), truck will start, run acceptably for about 1min, then I can see the fuel press gage falling, falling, falling eventually down to zero, whereupon truck stalls.

Okay, so I ground out the pump (at the test port) to force it to run continuously - same response - runs then dies. with the jumper still connected, and after the stallout, I can hear and see (gage) the pumps "struggling" to return fuel press to 32 (sometimes up to 40)psi - this takes probably 10 or 15 seconds to do, and builds up erratically in 5 or 10psi increments. When the press is back up, the truck will restart and run fine, for about 1min.

I'm stumped - I don't really know if the low press tank pump(s) are starving the high press pump, or the high press pump is cavitating / failing - or if the problem could be with the dual resevoir / selector unit....or this or that...or the other thing - throw a dart, I guess...

And I've changed out the FP regulator / FP relay already - in a hopeful attempt to rule that out. Subford, I bought a new thick film module to install, but I might save it pending this posts' responses -

This is a plow truck, and I'm a cheapskate, so I'm apprehensive to go out and spend $188 for a HP pump, or spend an afternoon wiping rust chips out of my eyes while taking the bed off for LP pump tomfoolery -any thoughts or similar experiences would be greatly appreciated!

 

I would say the TFI Module is good but it is a good idea to have a spare in the glove box.
The fuel pressure regulator is more than likely good, pull the vacuum hose off it and see if fuel comes out of the nipple on it when you ground the fuel pumps, no fuel it is a good one.
The IAC valve will not cause all of this and when you put your foot on gas you bypass it anyway.

I would say change the fuel filter first if you have not already and see if that fixes it.

If you hear the in-tank pumps run when this happens and you switch tanks and you still get the same thing than I would not think the socks are plugged in the tanks.

When you ground the fuel pumps go under and see if you can hear the hi pressure pump running and then stopping or chattering or something. If it does it may be the problem.

 

Here are some images and diagrams to look at if you have not already seen them.

Fuel System Diagrams for the 87-89 F series:

Electrical:
http://i54.photobucket.com/albums/g9...-89FSeries.gif

Mechanical
http://i54.photobucket.com/albums/g9...Fuelsystem.gif

Selector Valve 1:
http://i54.photobucket.com/albums/g9...Fuel/dfres.gif

Selector Valve 2:
http://i54.photobucket.com/albums/g9...l/FuelRes1.gif

Selector Valve 3:
http://i54.photobucket.com/albums/g9...l/FUELRES2.gif

Selector Valve 4:
http://i54.photobucket.com/albums/g9...ectorvalve.jpg

In Tank Fuel Pump:
http://i54.photobucket.com/albums/g9...9FuelPump2.jpg

High Pressure Fuel Pump + Filter:
http://i54.photobucket.com/albums/g9...mpFilter88.jpg

Fuel Pressure Regulator:
http://i54.photobucket.com/albums/g9...Fuel/fpr02.gif

Fuel Manifold:
http://i54.photobucket.com/albums/g9...elmanifold.jpg

Fuel Pumps test ground at the Test Connector:
http://i54.photobucket.com/albums/g9...taLinkConn.jpg

Inertia switch location 87-89:
http://i54.photobucket.com/albums/g9...SwLocation.gif

 

[QUOTE=subford]I would say the TFI Module is good but it is a good idea to have a spare in the glove box.
The fuel pressure regulator is more than likely good, pull the vacuum hose off it and see if fuel comes out of the nipple on it when you ground the fuel pumps, no fuel it is a good one.
The IAC valve will not cause all of this and when you put your foot on gas you bypass it anyway.

I would say change the fuel filter first if you have not already and see if that fixes it. did that first thing

If you hear the in-tank pumps run when this happens and you switch tanks and you still get the same thing than I would not think the socks are plugged in the tanks. that's my next area of concern

When you ground the fuel pumps go under and see if you can hear the hi pressure pump running and then stopping or chattering or something. If it does it may be the problem yes, I can hear the HP pump, but it sounds like it's "struggling" (aka stopping or chattering), and again the press builds up slowly and erratically. I'm not sure if the HP pump is being starved by the LP pumps, or the HP pump is failing - I'm going to try the time / volume test as described in the Haynes, but sounds like a pain in the a** trying to short the test terminal whilst directing an already dripping fuel line into the empty 32oz beer bottle I will have just finished.

I'm off to try it - send flowers to my local hospital burn ward.......



Thanks for your reply, Subford!