1989 7.3 IDI Issue while driving!

[tjs1992]

Hi,

I'm another new guy to the diesel world. I have recently bought a 1989 f250 5speed with 130,000 miles on it. Has ats turbo kit installed also. Truck is in great condition and runs well.....until it decides to randomly shut off for no reason as if it has lost fuel. It could take 2 minutes or 20 minutes before it restarts and drives like nothing ever happened. There is no warning and no loss of power. It simply chuckles and shuts down. The fuel lines have been checked for air leaks and there is a new fuel filter installed in the truck. Anybody have an idea what the issue could be???

Thanks

 

[laserjock]

Check the connection to your fuel shut-off solenoid on the injector pump. That's about the only thing I can think of that will kill it instantly.

 

[ryanecvbrown]

Check the connection to your fuel shut-off solenoid on the injector pump. That's about the only thing I can think of that will kill it instantly.

Agreed.
Check steering wheel in/out play also. I used to have a truck where the t-bolts had backed out, when I yanked on the wheel too hard it would pull on the ignition lever and turn the switch off until I banged on the steering wheel.

Usually when you're running out of fuel or starving the pump it's a gradual sputter and power loss til the engine dies. Sounds to me like you're losing voltage.

 

[gandalf]

Check the connection to your fuel shut-off solenoid on the injector pump. That's about the only thing I can think of that will kill it instantly.

That's what came immediately to mind for me also.

The electric connection for the FSS is pretty important. If the IP is not getting power through that wire, then nothing further will happen, although the engine will crank as long as the battery holds out. There are two wires , each with a spade connector, on top of the IP. The connectors are different sizes so they can't be confused so easily. The FSS is the one toward the front of the vehicle. If in doubt, pull the off, one at a time. The one which kills the engine is the FSS.

As a test, disconnect the wire from the FSS and run a temporary wire direct from the positive battery terminal to the FSS. If the engine does not die suddenly as you drive, then that would indicate the problem is somewhere in that cable system. IMPORTANT: If you do this temporary connection, the only way to shut off the engine is to pull the wire off the FSS or the battery.

 

[icanfixall]

Welcome to the forum..
All the above can be true. Also your ignition switch can be bad or out of adjustment too. The wire on top of the injection pump is the smaller of the 2 connectors. Its also the wire closest to the firewall. As already posted, just run a jumper hot wire to that pump connection from the battery of either side of the truck. You can still start from the ignition switch too. Leave off the normal wire that feeds power to that connection. Then if driving it tells you the engine runs and not shuts down you know which direction to look for the problem..

 

[tjs1992]

Well I finally got around to working on the truck and taking all the advice. I hooked up a small light to a wire from the ignition switch to be sure it was not going bad. Also hooked up a switch to the gas. When off the truck will not start so I'm certain it's hooked up correctly. Now for the interesting news. I drove the truck around some but maybe not long enough for it to shut off. Its 89deg outside so fairly warm outside. While driving the truck it suddenly started to idle high around 2200rpm but would go down of course when I put in gear. After a few miles it started to idle normal again and drove fine. After I got it home it was almost like it didn't want to idle down past 1200rpm and its a 5spd manual. Turn it off for a minute and it will idle back around 850 to 900rpm. Was this a sign that the fss is starting to go?

 

[icanfixall]

Sounds to me like the pump is shot. Might try removing the fuel filter and refilling it with atf. Get the engine running and listen for the change in engine sound then its running on the atf. Shut it down and allow to sit overnight. Next morning run it harder than normal to blow out the gum in the pump. If that is no help then its time for e rebuilt pump. DO NOT JUST BUY THE CHEAPEST EBAY PUMP YOU CAN FIND... The Hall of Shame forum is full of members that got ripped off by these cards.

 

[Michael Fowler]

Sounds to me like the pump is shot. Might try removing the fuel filter and refilling it with atf. Get the engine running and listen for the change in engine sound then its running on the atf. Shut it down and allow to sit overnight. Next morning run it harder than normal to blow out the gum in the pump. If that is no help then its time for e rebuilt pump. DO NOT JUST BUY THE CHEAPEST EBAY PUMP YOU CAN FIND... The Hall of Shame forum is full of members that got ripped off by these cards.

I agree with all that, and since you are new to the forum, let me add......

DO NOT REMOVE THE INJECTION PUMP BY PULLING THE HALF-ROUND COVER!!
Read the tech section articles. Pull the pump the "correct way" and save a lot of time. Do it the way that "looks" easy and you will add untold hours of misery to the job.