sudden power loss while driving - 1994 XLT 11/10

[shifty1]

Good afternoon,

My truck has a tendency to shut down while driving.
There is no warning, and no codes seem to be triggered(at least the ch eng light hasn't come on).

???

If I throw it in N and turn the key off for a few seconds, I can usually get it to start while still in motion.

Other than this, everything seems fine. No trouble starting, idle is fine etc.

If anyone has any ideas as to the cause of this, please let me know.

Thank you

 

[BigBlueWolf]

1994 XLT...I didn't see any responses to your problem. Did you get it fixed? I'm having the exact same problem now. It started about a month ago. Any information would be greatly appreciated.

 

[shifty1]

Hey, my first question is whether you have pulled any codes out of it yet??

I was able to pull a few (I'm not sure what they were, they are in another of my posts). They both had to do with a failure in the fuel system (1 for the primary/fuel pump and 1 for the secondary/relay).

I have not been able to completely stop it, but it only happens every month or so (but it'll happen a few/alot of times within a short period when it does happen). I found that after I tapped the codes, I would not have problems for weeks.

I have read a lot of posts that suggest it may the trucks computer, but I haven't done anything with that (there is one on e-bay right now (currently $9.99us w/ 1+days left).

I would believe that it is either the computer, or spark judging by the way it dies so suddenly. It is such an intermittant problem, I doubt that is a problem with any actual mechanical components in the fuel system (if it is in fact a problem w/ fuel delivery), because you would figure that there would be a comlplete failure.

Not that I can necessarily help you, but could you tell me if you have done anything previously to try and stop this?
I have cleaned my MAP sensor, IAC valve, changed all plugs, fuel relay, fuel filter.


Sorry I can't be more helpful, but with the fact that it only happens here and there, it is very, very hard to diagnose.

 

[FirstFord]

i have a cheap and easy suggestion, check the fuel pump relay under the hood, switch the fuel pump relay and the ac/heater control relay and get in and try to turn on the heat, if nothing happens you have got a bad relay.

 

[shifty1]

Would the problem be intermittent with a bad relay??
If the relay was blown, would it not be a full time problem?
When I mentioned that I had changed the relay, I meant that I switched the relays, and I am still having the problem.

 

[TheRookie]

Could be a relay. I have a simmilar problem but it isnt a relay. I know because I have changed all of them. When exactly does this happen? On the gas, off the gas? WOT? highway? I have changed out most of my damn truck and have this problem. Another forrum member said it may be a fuel pressure regulator. When I get a cahnce to swap that I will let you know

 

[BigBlueWolf]

Wow! You guys have tried everything that I was considering as possibilities. Unfortunately, it didn't give any codes, that's why I am so confused. I have been reading some of the other forum posts and thought that I would start with the IAC. And like you, it happens so sporatically that it's hard to gauge. It will go 3 weeks without incident and then suddenly...loss of power. Even if I downshift, it won't really accept throttle. I truly don't get it that as soon as I turn off the switch and restart, the problem goes away.