STILL STUMPED: 91' F150 .302

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Big Bob - 14 May 2005 02:43 GMT

This stupid truck of mine still doesn't want to run.

I have tested fuel pump, tests perfectly and rock solid.

IAC appears to function normally and be in order.

The truck idles perfectly, engages into gear with no trouble, but when you
step on the gas - motor cuts out completely.

I am befuddled. Oil is clean and dry. Coolant is clean and clear.
Everything appears to be in order.

Any thoughts? Is there a MAF on this thing? I don't believe there is, but
you never know.

Any thoughts or advice that anyone has would be greatly appreciated.

Thanks,
BigBob

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Bob - 14 May 2005 03:45 GMT

> This stupid truck of mine still doesn't want to run.
>
> I have tested fuel pump, tests perfectly and rock solid.

How do you know this? Did you check it with a gauge?

> IAC appears to function normally and be in order.
>
> The truck idles perfectly, engages into gear with no trouble, but when you
> step on the gas - motor cuts out completely.

What do you mean by "cuts out"? Does is stall or just lack power so bad it
won't pull itself?

> I am befuddled. Oil is clean and dry. Coolant is clean and clear.
> Everything appears to be in order.
>
> Any thoughts? Is there a MAF on this thing? I don't believe there is,
> but
> you never know.

No, you've got a MAP sensor and I doubt it's causing your problem.

> Any thoughts or advice that anyone has would be greatly appreciated.
>
> Thanks,
> BigBob

Check the basics, get a spark tester and make sure you've got good spark at
the plug, see if the computer has stored any codes, check fuel pressure with
a gauge if you haven't already.
Bob

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Big Bob - 14 May 2005 17:08 GMT

>> I have tested fuel pump, tests perfectly and rock solid.
> How do you know this? Did you check it with a gauge?

Absolutely. Dang thing cost me $56. It measures at a rock solid 37 psi
constantly without even the slightest hint of anything awry.

>> The truck idles perfectly, engages into gear with no trouble, but
>> when you step on the gas - motor cuts out completely.
> What do you mean by "cuts out"? Does is stall or just lack power so
> bad it won't pull itself?

There is not much in the way of stalling. I will give an example. Last
night I started the truck. Idled fine in the driveway. I depressed the
brake, and shifted the truck into drive. Nothing happened, the truck
slipped into gear. I let off the brake, the truck did not move (should
have given an inch at least) and when I depressed the gas pedal, the engine
stopped. It did not chug or anything -just halts. This is consistent.

One other thing to note, once the motor stalls like that, it will not crank
again for at least 4 hours. Then it will start up with no problem,
however, I still have the symptoms described above.

> Check the basics, get a spark tester and make sure you've got good
> spark at the plug, see if the computer has stored any codes, check
> fuel pressure with a gauge if you haven't already.

I will check spark, however, seems unlikely to me seeing as the motor idles
with no miss or hiccups.

That brings up another question. I would normally take this thing to
Autozone and have 'em scan the codes, but I can't get the truck there. Is
there a way to read the codes myself without buying a crazy expensive tool
to do so?

Thanks for the advice Bob. I greatly appreciate it.

BigBob

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tom - 14 May 2005 23:22 GMT

just a thought, did you check the exhaust?? a plugged exhaust system will do
this.

> >> I have tested fuel pump, tests perfectly and rock solid.
> > How do you know this? Did you check it with a gauge?
[quoted text clipped - 33 lines]
>
> BigBob

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Bob - 15 May 2005 04:43 GMT

>>> I have tested fuel pump, tests perfectly and rock solid.
>> How do you know this? Did you check it with a gauge?
[quoted text clipped - 14 lines]
> engine
> stopped. It did not chug or anything -just halts. This is consistent.

Even at idle it should creep forward or back, looks to me like you've got a
couple of problems.

> One other thing to note, once the motor stalls like that, it will not
> crank
[quoted text clipped - 8 lines]
> idles
> with no miss or hiccups.

It's not the most likely problem but don't rule it out until you've checked
it.

> That brings up another question. I would normally take this thing to
> Autozone and have 'em scan the codes, but I can't get the truck there. Is
> there a way to read the codes myself without buying a crazy expensive tool
> to do so?

Ground the STI connector and count the flashes. Search the net if you don't
know what I'm talking about. It's been posted may times.
Bob

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