engine computer problems?
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engine computer problems?
hey guys im new here I needed help on figuring out why my truck is running only on 4 cylinders.... its a 95 f150 I rebuilt my entire engine with my dad, knowing that he used to be a mechanic i decided to rebuild it. (more of a learning experience) all internals parts are fine. Up with torque measurements ect. i bought a new distributor, wires, spark plugs, but numbers 5,7,3,4 are not firing. we've tried everything with the distributor plugs and wires. there is fuel getting to each cylinder because iv taken the plugs out and have seen and smelled gas on them. the only thing we could think of is something electronically/ electrically. so we plugged in the OBD1 tester and alot of codes came up. mostly to do with the electronics. one of which was #15 eca failure. there was #87 and also #81. i went to buy a new computer because of what it said, still no change in firing order. 
so my question is, does anyone have a clue on what it could be or have any of you has a similar problem, remember its a new engine.
so my question is, does anyone have a clue on what it could be or have any of you has a similar problem, remember its a new engine.
Fleet Owner
Joined: Oct 2005
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From: Kentucky
You should be getting three digit codes, not two.
The computer fires the plugs based on the stator trigger. There is a tooth that is narrower than the others. This signature pulse tells the computer where cylinder #1 is. Weird things can happen when the distributor is not stabbed correctly. This usually manifests itself with driveability issues, not missing spark. Worth a shot to verify.....
The computer fires the plugs based on the stator trigger. There is a tooth that is narrower than the others. This signature pulse tells the computer where cylinder #1 is. Weird things can happen when the distributor is not stabbed correctly. This usually manifests itself with driveability issues, not missing spark. Worth a shot to verify.....
Fleet Owner
Joined: Aug 2005
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From: Easton,Ks
Sounds like the VSS wave train to the PCM Computer is bad and the PCM Computer thinks the truck is going to fast and is trying to slow it down.
I would guess maybe you have a bad PSOM.
I would guess maybe you have a bad PSOM.
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Fleet Owner
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From: Kentucky
As previously stated also verify all the connectors are plugged in and there are no bent pins.
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Fleet Owner
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From: Kentucky
Ford started the transition to 3 digit codes around 1991. Subford has stated some went to three digit as soon as 1989.
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I bought a new computer the pcm one because that's what we thought it was too, but there was no change in the firing order
Fleet Owner
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From: Kentucky
Disconnect the SPOUT then check your spark. Even better disconnect the computer completely. This will make the spark control revert to basic mode. The ICM will trigger off the raw PIP signal.
Cargo Master
Joined: Mar 2007
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From: Arcadia, Fla
Recheck the ignition order of that 302, it could be the H.O.302 ignition order instead of the standard 302. I read a thread few days ago about that.
Just removing the SPOUT will allow no ECU timing functions and engine will run on base timing. If you remove the ECU then the injectors will not be working and engine will not run unless you use starting juice to give fuel to engine.
Just removing the SPOUT will allow no ECU timing functions and engine will run on base timing. If you remove the ECU then the injectors will not be working and engine will not run unless you use starting juice to give fuel to engine.
Fleet Owner
Joined: Oct 2005
Posts: 20,789
Likes: 1,753
From: Kentucky
Recheck the ignition order of that 302, it could be the H.O.302 ignition order instead of the standard 302. I read a thread few days ago about that.
Just removing the SPOUT will allow no ECU timing functions and engine will run on base timing. If you remove the ECU then the injectors will not be working and engine will not run unless you use starting juice to give fuel to engine.
Just removing the SPOUT will allow no ECU timing functions and engine will run on base timing. If you remove the ECU then the injectors will not be working and engine will not run unless you use starting juice to give fuel to engine.
Wrong firing order would not cause a no spark on certain cylinders condition.
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