Alright, 1st time posting here so be gentle please.

1995 f150 5.0 4x4 with 240k miles

symptoms;
. 1. Slight miss at idle.
. 2. Will not accelerate unless throttle is darn near floored, and maybe 1 out of 10 times it will seem to function as it should.
. 3. CEL comes on but only intermittently, never at idle.
. 4. Exhaust seems to blow out much harder than my 92 with the 300 and my friends 2006 with the 5.4L.
. 5. Catalytic converter seems too hot to me.

checked;
. 1. Plugs (all good and getting spark)
. 2. All vac lines look good, no hissing.
. 3. Timing is perfect.
. 4. Spray carb cleaner all around vac lines, egr, intake and even the plugs with no change in running.
. 5. Fuel pressure (34 key on and about 37 psi running)
. 6. Compression in tolerance of Haynes manual, I forget what they all were but we're withing 10% of each other.
. * tried to pull codes btw, will not show codes at idle and I think the diagnostic port for the obd 1 is messed up, have tried with and without obd 1 scan tool

The following are all things that have been replaced (for give my part swapping, as I couldn't pull codes it was kind of a best guess scenario).

Replaced:
. 1. EGR
. 2. FP Regulator (old one was bent where vac. Hooked up anyways.)
. 3. TPS
. 4. IAC
. 5. Fuel Filter
. 6. Throttle body gasket
. 7. Air filter
. 8. MAF
. 9. Battery (kind of unrelated as old one was shot anyways)

the next things on my list to try (unless you fine folks here can help) is to try a new coil and I may hollow out the catalytic converter since it seems to me like it gets much hotter than it should. After this I am at a complete loss (more than before). I've tried not to just throw parts at it but nothing is seeming to workout right. Its a truck I bought from a friend and he is at a loss too. Any help would be greatly appreciated.

 

Your first mistake was ignoring the obvious. Until you can fix the reason why you cannot pull any codes you are wasting time and your money.

At the very least you should clean the contacts on the data link connector, then try running the KOEO tests and stored code display. If that does not work, pull out the computer then inspect for signs or swollen/leaking capacitors.

 

My 89' F-350 will pull codes with the Innova scanner in the conventional way.

My 89' F-250 won't work with the Innova at the data link connection, but I can read the fault codes with an analog meter under the hood with the prescribed jumper wires, or count dash "check engine" light flashes.

 

I live 2 hours away from where truck is, I will try a different code reader on it when I head there again today. And I'll try a meter and test light too HOWEVER the CEL will not come on at idle, I've tried and tried but it is only intermittently on while riding and never at a stop

 

If the light came on under any circumstances there will be a code stored in memory. Just because the CEL is off does not mean there are no stored codes.

Clean the pins on the connector before throwing any more parts. A good dose of contact cleaner and/or fingernail file will make those pins shiny. As previously stated if the pin cleaning does not work, pull the computer for an inspection.

 

I have contact cleaner, small files and some dielectric grease, I'll give it a shot. The computer is fairly new (sometime in the past 3 years). In the mean time any suggestions on anything else to check while I'm there would be great. I'm tired of making the 2 hour trip lol but I need to get this truck home soon as I can.

 

Also if anyone knows the voltage each pins on the ecc port is supposed to have or if they are supposed to be ground I will check and see what I have on each.