Again with the grounds. You rarely can tell just by looking at them and making sure they are tight. These trucks are famous for the gound wire rotting out under the insulation where unless you peel it back and/or do a resistance check you can't tell if they are bad.

My 5.4 wouldn't idle/start and it turned out to be my IAC. Just for grins have you ruled out the IAC? (No code will be thrown with a bad IAC)

 

When I checked the grounds, I didn't remove them, they looked fine, no signs of rust or corrosion. I will further check them today, I will clean them and such. I would like to ohm them out, any ideas what kinda of resistance numbers would be too high?

 

As far as the IAC goes, I replaced that already. The head service tech at the local ford suggested that when I was describing my problems.

 

I do not know how the Snapon Scanner works but I have the diagtec scanner. It is palm pilot based. The tranny problem codes are in the GEM test not in the PCM. I would suggest unpluging the tranny harness and checking for corrosion or dirt.

JMC

 

Well, I can't say that i have investigated the battery cables/grounds yet, but I did stumble over something else. I was playing with the scanner today and pulled some more codes.

P0500- Vehicle Speed Sensor fault<--I blame that on the wheels

B1318- low battery voltage at module<---this one I could use some help on. What module is this in reference to, and what could be the problem/ fix.

 

As others have stated here the first thing I would check before replacing any parts would be all the ground connections & also the positive connections as well, at the junction box on the firewall & power distribution box . A loose and/or a corroded connection can cause a low voltage condition, causing DTC & driveability problems.

 

I checked all of the connections and grounds and everything seems to check out. I do think that i may have finally stumbled across a fault code that seems to consistently come up when the truck is acting up.

U1262 SCP data fault for J1850 BUS

What does that mean?

Two more that I pulled but haven't came up since are:

B1681- Pats tranciever mod sig not recd
U1147- Scp data fault for veh security

I have a feeling the last two are related to the remote start, I am in the process with making an appointment to have that removed at Tweeter.

 

ttt

 

Hmm, no help on the codes..., allright I did have the remote start removed, and to know suprise the truck still isn't running correct. It is so hard to pinpoint a problem when the truck doesn't do the same thing all the time. And even when it is running bad, sometimes is seems as though they are different symptoms. Right now, it sort of surges in low rpms, and then you can feel it kick in once it revs up to about 4grand. I've just about pulled all of my hair out. The funny thing is is that it is probably something soo simple.

 

This may or may not be relevant, but I had an 88 F-150 that nearly got me killed a couple of times because like you said it would die just like the key was turned off. Turns out after lots of trouble shooting I finally got a code that was similar to that (water temp sensor something or other). And I thought... what could that have to do with this?? Well after studying the wiring diagram there was a direct conection to the distributor module and in fact if that 3 dollar sensor goes bad the truck would not run or would shut off randomly usually about the time the engine was just about warmed up on a cold winter morning. I wouldn't disregaurd that code just yet.

Hope that helps

 

I was out dredging for information on an unrelated stalling issue that I'm having with my 94' when I stumbled (pun intended) onto your post.

I lived for years with the identical problem on my 85 1/2 (first year for EECIV in the F150). The problem eventually evolved from random dropping out at high speeds to random no starts, that on several occasions left me temporarily dead in the water. I say temporarily because the truck would eventually start and for no "apparent" reason. Sometimes it would start hot, sometimes cold. Sometimes it would start on the second attempted crank - sometimes it would be an hour later after 30 attempted cranks.... there was just no consistency to the problem.

Like you I replaced several sensors, pulled the codes, ran both koeo and koer, but while I was running the truck daily was never able to cure the problem. I finally got tired of dealing with the issue so I demoted it to my yard truck and replaced it with a 94’. Of course using it less frequently to do yard work didn’t solve the problem either, seems like any time I went to use it after that I would always struggle with it starting.

One of those days that I was fuming over this problem I realized that the engine had started after I had been poking around under the hood. It suddenly dawned on me that I had spent a lot of time scrutinizing sensors but had never really given much thought to the harness. After purposely wiggling the harness in the correct location I was able to repeatably make it stumble or start/no start.

In my case Ford had designed an unprotected (electrical tape only) Ground splice into the harness on the front of the engine, right under the distributor. My recollection is that there were 4 or 5 wires crimp welded together in this location. Over the years moisture had crept through the tape and severely corroded the copper wire at the splice. One wire in particular, a gnd. return to the EEC module, was much worse than the others. It in fact was only making contact to the ground because it was touching the other grounds; the mechanical connection had completely rotted out.

So if you haven’t already tried this, work your way around the engine harness while the engine is running. If you’re able to make the engine stumble you just may have found root cause of your problem.

Wiggling the harness is a fairly basic troubleshooting technique that I neglected for years. It’s a lot easier to believe a module or sensor has died than to believe that a copper wire or connection has failed. Since I cut back the rotten copper, replaced it, soldered the splice, and protected the whole mess with adhesive shrink, I have not had a single stumble or no start problem.

Hope this helps. paul