This morning was the third time my truck has cut off on me on the interstate. It did this last Thursday and Friday mornings and it has run fine until this morning. I had the fuel filter changed, yesterday. The check engine light has not come on. It seems to be happening within the first few minutes of getting on the interstate and getting up to highway speeds (60-70mph). All of a sudden the truck starts hesitating and I watch the tach drop below 500 rpm. It tries to recover for a while and then it dies. I pull off on the shoulder and let it sit for a minute and then crank it back up and drive 15 more miles to work without a problem. Does anybody have any suggestions. My mechanic couldn't find anything wrong and didn't know where to start as the CEL didn't come on. Thanks in advance for any help.


'99 F150 XLT 5.4 V8

 

Perhaps your EGR grooves are clogged, not letting enough air/fuel into your motor. This is a common problem with these trucks, but it usually pertains to a rough idle or hesitation under accelleration. Still a possability though.

 

Also, no codes are being generated. Do you think it might be the fuel pump? I will try cleaning the EGR this weekend

 

How long have you driven before getting on the interstate?

 

I usually let it warm up for three to five minutes in the driveway. Then it is about 2 miles to the interstate. The max speed before getting on the interstate is about 40 mph.

 

I'd be suspicious of fuel pressure..

I'd probably duct-tape my fuel pressure guage to the hood so I could watch the pressure.

Steve

Hmm, is Blue Collar TV on tonight???

 

Thanks for the input. I am willing to try just about anything. The engine cutting off at 70 mph ain't cool....

 

One of your key points is no CEL lamp.
My suspection is a power related problem.
Might be as simple as a fuse coming out of it's socket, that supplies the PCM.
No power no code.

 

I checked all my fuses and relays and they seem to be ok. Any other suggestions? It definitely seems to be related to the temperature outside. On cold mornings like this morning it just shuts off. This morning it shut off before I got on the interstate. It won't restart immediately after shutting off, but if I wait a minute or two it fires back up.

 

I know it's not a Ford....but my 96 GrandAm did the Exact same thing. Replacing the electronic spark control modual in the distributor solved the problem. So, maybe check for spark as soon as it dies. If no spark, this might be the problem
Just an idea.

Jim

 

I'd lean toward the fuel pump.

Check the fuel pump pressure.

 

Well we had our first cool weather in the South this week and my truck has started acting up again. It has run great all Spring and Summer. When I left for lunch today it was a little slow to start. I accelerated onto the interstate and the truck starts lurching like it is running out of gas. It did this for about a mile, but never cut off. It then recovered and I drove it for about 20 miles without a problem and of course no codes. Last year trying to solve this problem I wasted a lot of money on a new fuel pump, fuel filter. I also had the spark plugs changed and cleaned the air intake. Any ideas on this irritating problem would be greatly appreciated.

 

Is your truck stock? If not what mods do you have done to it?

JMC

 

yes everything is stock. 99 F150 XLT 4x4 5.4L, 111k miles and this is the only problem I have had. Any help would be greatly appreciated.

Thanks

 

Did you notice if the gages did a full sweep after you restarted the engine?

JMC