92 f150 shudders & misses when warmed up

[reino134]

92 f150 302 4X4 aod

I have checked through all of the forums and have yet to come up with the solution to this problem. The truck runs fine on a cold start and runs down the road the way it should. Once it warms up it starts missing and causes the truck to shutter. It will also sputter pulling away from a dead stop, once it is warmed up (does not do any of this from a cold start). I have scanned it quite a few diffferent times and get no codes. i will list what I have done so far and maybe you can help tell me what I missed!

replaced all vacuum lines (verified routing about 10 time)
replaced EGR Valve, EVP, EGR control solenoid (tested new parts all good)
replaced TPS (tested TPS and adjusted it properly)
replaced Idle Air Control Module
replaced MAP Sensor (tested good)
replaced Ignition Coil (tests good)
replaced Ignition Control Module
replaced plugs (autolite Platinum) gapped properly
replaced wires (have been routed properly to avoid cross fire)
replaced air filter
replaced fuel filter
replaced O2 Sensor
replaced Engine coolant temp sensor (tested good)
replaced cap and rotor (bronze conductor set)
ran injector cleaner through system for last 5 tanks of fuel
checked fuel pressure at rail. 38 psi engine off, 32 psi engine running, 40 psi running w/ vacuum line disconnected.
checked upper intake plenum for leaks, could not detect any
switching tanks while driving does not affect this at all


The motor is a fatory long block crate motor installed by ford about 2,000 miles ago. Just paid them $90 to put it on their machine, for them to tell me that they have no idea what the problem is. Gotta love those dealerships!!

Anyone with any suggestions, ideas, anything would be greatly appreciated
Randy

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[Scrapper]

i'm not real sure but i think that fuel pump should run around 60psi? cat converter maybe clogging up.also sometimes you may have 2 02 sensors and if your running ethanul threw it not good.try putting some sea foam in it.

good luck...

[reino134]

wouldnt the cat clogging up throw a code?

[Scrapper]

well it should but i've seen them not to either.take to thrifty or some other muffler shop they can find out..

[W-T-Katt]

I have a 96 F-250 460ci. fuel injected. I've got the same problem going on with mine. So far all I've replaced is the temp. sending unit for the computer and I'm in the process of the fuel filter. Any help here diagnosing htis problem would be greatly appreciated. I can't afford to just start replacing everything under the sun. lol
Thanks

[reino134]

replaced the distributor and ignition pickup this morning and swapped back to copper motocraft plugs. Did not help at all..........

[rhandwor]

I noticed you changed the EGR valve did you clean the inlet? If you used an aftermarket EGR valve did you install the proper washer. To much flow will cause problems. Fords have a lot of wiring problems I would get a wiring diagram and ohm wires for the pickup in the distributor. On a 1985 T-Bird I had I checked the voltage coming to the module and it was around 8 volt.
I replaced the ignition switch which brought it up to 12 volt. Check the vacuum port to intake manifold they sometimes plug solid. Make sure the shielding wire is grounded if you ever replaced without using shielded wire they will cause problems like yours. I had to replace the wires on my 1985 T-Bird to get it to run properly. I found a harness at a junk yard and removed it on both vehicles. Ohm'd all wires and inspected them making one good harness out of two.

[reino134]

thanks for the ideas, I'll check into those this week

[reino134]

Originally Posted by rhandwor

I noticed you changed the EGR valve did you clean the inlet? If you used an aftermarket EGR valve did you install the proper washer. To much flow will cause problems. Fords have a lot of wiring problems I would get a wiring diagram and ohm wires for the pickup in the distributor. On a 1985 T-Bird I had I checked the voltage coming to the module and it was around 8 volt.
I replaced the ignition switch which brought it up to 12 volt. Check the vacuum port to intake manifold they sometimes plug solid. Make sure the shielding wire is grounded if you ever replaced without using shielded wire they will cause problems like yours. I had to replace the wires on my 1985 T-Bird to get it to run properly. I found a harness at a junk yard and removed it on both vehicles. Ohm'd all wires and inspected them making one good harness out of two.

Thanks for sending me in the right direction! Replaced the EGR Valve with the proper one. Advanced Auto had the wrong part # in their computer for the valve. Amazing how they look identical, but work so different.

Thanks again

Randy

[W-T-Katt]

OMG!!! Does that mean that you finally got it running right??

[reino134]

Runs like new, checked the manufacture date in door jamb and it was 9/91, the EGR valve was different for the 91 vice the 92. How did you make out on your fuel filter?

[Rick Humerickhouse]

I have the exact same problem as reino134 on my 93 f150 5.0 L, with the shuddering, etc., after warm up, and have replaced nearly all the identical parts as reino134. I, too, replaced the EGR Valve, so probably need to re-check to make sure they gave me the right one.

One question I have, though, is the shielded wire mentioned in your post, the spark plug wires, or some other wire that must be shielded? I'm not clear on that post.

One other question. I had someone tell me that my spark plug wires might be arching, but not sure how, as I replaced them as well, and then to top it off, I put wooden clothes clips anywhere they touched, but still have the problem...

Any help would be greatly appreciated - THANK YOU for something that is very aggravating and then some!

P.S. If an post isn't possible, please call me, Rick, at 913 461 3432...THANK YOU....

[rhandwor]

The shielded wire has a wire mesh like a screen around it make sure it is grounded or not removed by someone else.

[Rick Humerickhouse]

Okay, stupid question, as I'm not sure I read the original post correctly. When you talk about the "shielded wire has a wire mesh like a screen around it", what exactly are you talking about or where can I find it. Or, are you talking about the spark plug wires, or what exactly is this shielded wire, you are talking about? I'm a little confused and must apologize, but was never clear on what this "shielded wire" is... THANK YOU!!!! Also, feel free to call me if explaining in writing might be too time consuming for you... Rick Humerickhouse, 913 461 3432... THANKS very much on either which way you respond...

Originally Posted by rhandwor

The shielded wire has a wire mesh like a screen around it make sure it is grounded or not removed by someone else.

[rhandwor]

Look at the distributor TFI module it would be around the wires leading to this plug.
Sometimes the pickup in the distributor will go bad but it acts like the key switch was turned on and off.
If you decide to replace this you need a tool.
Use yahoo search type in thexton distributor tool. A lot of them will be listed for ford.