Hi, I have a problem I can't get figured out with my 90 F150 351 EFI - I has been runnig ok till last week and died at a light, could not start. had it towed and when home started up ok - ran 15 mins and died idling. I had an IAC and tried that, no different. I pulled the code and got an 85 (purge canister solinoid failure) checked the solinoid and it was bad. replaced and starts ok, idles 15-20 mins and dies and won't start. Pulled code and get "no code". Tried it this morning and started up again - I am afraid to drive down the road any farther than I feel like pushing the truck. I need any help out there. Chilton/hayes books no help - Thanks for the time to read long post -

 

My mom's Burban used to do that.

Are the fuel pumps running when it shuts off? On my moms truck the wireing would heat up and fuse together shorting out the pump. Is it a Dual tank? try switching tanks.

DT

 

It could be ignition related. After it dies, are you getting a spark?

 

Sounds like fuel feed.

Technically - this should be in 90 F150 forun, but this one goes broad-spectrum, I had a friend with a Mustang Turbo that did pretty much EXACTLY what you describe.

We were convinced it was vac-line related before it was all said and done.

If your fuel pump pressure is right, it would only be the fuel metering system (EFI, Yes?)

Okay - now the question:

What forum is best suited to find this?

Fuel?
90 F150 exclusively?
Or "Other"...

EXPERTS? Circle the wagons... Is this more likely EFI, VACCUUM, Engine Control and FUEL Injection, or what?

 

It ain't electronic in origin - it would be either intermittent or instant if it was.
Check voltages on your electric fuel pump to make sure. At the very least - if you have an electric in-tank pump you should hear it running with the key in the run position.

EFI don't run without pressure. Could be a weak pump, or bad regulator.

Also check to see if your collision interrupt has been triggered. Its an inertial switch that cuts power to the fuel pump if you have a sudden sharp stop. Location should be in your manual.

~Wolf

 

Just a head's up

This thread will probably be moved to the 87-96 truck forum.
This forum is for those topics that aren't covered by their own forum

ps: You might also put the actual topic in the title so we know what to expect,we're already here to help

 

It almost certainly isn't fuel related, or it would be happening all the time, and not after idling for 15 minutes.

At any rate, this will get moved to the 87-96 forum shortly.

 

Fuel system is a norm for delayed reaction - such as described. It relies on pressure, not instantaneous contacts.

But electrical could cause a fuel problem.

I bet fuel.

Oh look at that - we're in the 90's forum!

(I was expecting it)

 

ok everybody - we have moved to the 90's forum. Now that we are past that excitement I still need some help with the truck.
I can start it after it sits for a few hours, it will run for 15-20 mins on either tank. Then just stop - it will turn over but no start. I had looked at similar posts and someone suggested that the fuel pressure regulator might cause something like this. I originally got an 85 error, replaced the purge solinoid and that cleared. It is still dies and now I get a "no fault" code. I have replaced the IAC and no change - I'm open to ideas - Thanks

 

I have a '88 f-150 302 that did the same thing, turned out to be the fuel pump on the frame heating up & shutting off.

 

As I said - are you getting spark after the engine dies?

 

andym - no I haven't checked for spark, got sidetracked running a 51 code. could a bad ECT cause my problem with it crapping out as it warms up? I will pull a plug and check for spark - thanks for the reply!

 

After the engine dies
1) check for spark
no spark - check tfi (esp if mounted on distributor)
2) check for fuel pressure ( about 32 psi running, about 38 primed but not running)
no/low fuel pressure - try new fuel filter & check pumps and wiring to them
We've also seen a few vapor locks this past month so
check where the lines near the exhaust and engine.
3) check for injector firing (You should be hearing them click with a mechanics stethoscope)
no click - check PIP
4) check for plugged exhaust - disconnect y-pipe and see if she'll stay running

Thats roughtly what I would check for and in the order I would do it.
Hope I helped,
Popa Tim

 

When the engine is warming up, the truck is running in "closed loop" mode wich means its bypassing the ECM a.k.a. PCM a.k.a. ECU(main computer basically). When the truck has reached running tempurature(usually about 175 to 185), it switches its controls over to the ECM. If the ECM is not working, the truck will barely run or not run at all because all the signals used to run the ignition will be way out of wack or gone completly.

I would first replace the ECM/Ignition Control relay located next to the engine compartment fuse box.

Another thing you may want to try is to disconect the SPOUT connector after it dies and see if the engine will run then.

 

ok - i will try the tests when i get home tonight - i did meter the ECT this morning while cold and got 31.12 k ohms - book says it should be 58k - 40k when cold. could this 51 code be related to the part where the truck dies after warming up 15 mins ?