Ok - going out on a limb here but if you've got 246K miles on the engine and haven't changed the timing chain, that's where I would start. If the chain hasn't jumped time, then it's floppy enough that the valve & ignition timing are being thrown off. From what you say about the erratic timing with SPOUT in, it may have jumped or is getting ready to.

Just a thought - take it for what it's worth.

 

We thought about that, but with the timing staying steady as a rock with the SPOUT out, we kind of eliminated that possibility.

My uncle had a thought and I think he's on the right track. He thinks that when we pressed the gear back on the distributor, there's a chance the shaft got bent ever so slightly, which would skew the PIP signal and in turn have the ECM constantly changing to the radically different timing settings.

So, I guess I'm gonna try a new distributor and report back.

 

The damper may have slipped some also so when it says 10* BTDC it may not be.
You may need to set the timing with a vacuum gauge.
Pull the SPOUT and set the timing to the highest vacuum reading.

 

That may be a possibility that we can look at after this initial problem is resolved. I don't see how a slipped balancer could have the ECM changing the timing every 1-2 seconds and from 8-50°. I'm not throwing out the idea at all and appreciate every bit of input you have given, but I would think if the balancer had slipped it would still be somewhat steady at idle even if it was off a few degrees, not to mention none of this was happening until we rebuilt the distributor.

 

I think what he means is that it would read steady, but it might be off far enough advanced, that when the computer advances it things go too far. The computer the attempts to adjust back which causes the erratic timing you are seeing.

Granted the same is true if there are problems within the distributor throwing the signal to the computer off. Since that's less labor intensive than figuring out the balancer I say it's as good a place to start as any.

 

Makes sense in either case. I'm just relieved that we're finally getting somewhere. I do think we'll try the distributor first since none of this was going on before we replaced the PIP. If that doesn't do it the balancer will be next on the list. Using his scan tool and verifying it with the light made both of us have an ah ha moment. I'll be working the next few days, but we're gonna try for Tuesday or Thursday to replace the distributor and I'll report back.

 

From what you say, it sounds as though you're on the right track. I've never changed just the PIP but usually change the whole distributor. I'm too ham-handed to get it in without messing something else up.

 

Forgot to mention, I've ran the timing all the way down to 0° BTDC on the tape with no change at all in how the truck reacts with the SPOUT in and naturally a very noticeable difference in power. I would think if the balancer had spun that much, or more, taking 10° out of it would at least take some of the detonation away and make the symptoms somewhat better.

Like I said earlier, I'm not looking over your suggestion by any means and do appreciate your input because you've brought a lot to the table in this thread. Bouncing ideas back and forth has gotten me waaay closer than I was before I started this thread. Before I pull the trigger on the distributor, I will try more troubleshooting to eliminate the possibility of the balancer.

 

Right. We both realize with the SPOUT removed that the computer no longer controls timing. I was just stating that whatever signal the computer was getting, it was showing on the scanner that it was attempting those corrections so far as we could see on the live feed from his scanner.

I've tried both the original ICM and the replacement ICM, both provide the same results, so I'm leaning toward it not being an ICM issue.

Both scanners showed the same or similar results although his is waaay more capable than mine. Again, I don't think both scanners are lying to us.

Wiring problem is a possibility I suppose, but I would find it highly coincidental that shielding, insulation or a ground issue would surface right after we rebuilt the distributor. The truck was 100% before the PIP went out.

Which brings us to the PIP and this is where personally I think the problem lies now. Of course, my track record this far in trying to find the problem has been less than successful.

 

The whole reason I decided to replace the PIP instead of the whole distributor was that my choices were either a Cardone unit which I've seen and heard countless negative reviews on or a performance distributor such as MSD, Accel etc. Ford no longer makes replacements. I figured as long as the bushings and everything were good, replacing the PIP in the OEM housing was the best bet. It's not terribly difficult, but a press is a must for the gear along with patience in order to get the roll pin aligned correctly. Knowing what I know now, I probably would have been better off replacing it with a lifetime warranty unit from a parts store and just replacing it as the need arose.

 

No argument about the Cardone rebuilds here - I try to avoid the brand unless I have no other choice. The last one I did I was able to find a new one (not rebuilt) from Spectre Performance. It's still Chinese, but hasn't given me a moment's grief.

 

I had almost the exact same problem as you with my 95 f250 5.8l: Truck ran fine, then one day cranked and didn't start until third try. Couple days later it stalled going from reverse to drive. It started right back up and drove fine 30 miles home in stop and go heavy traffic. It was 102 outside in San Antonio and it ran a little warm, with the needle about 2/3 towards hot. But once we got moving again it cooled back to normal and it ran fine the whole trip.

Next day it quit on me 3 miles after I left the house. 85 degrees and engine just reaching normal operating temp. Engine died all of a sudden but all accessories still worked. Crank but no start. Got it towed home. After much research and help from the forum I figured it was a bad PIP sensor.

I got the old sensor out of the distributor but the teeth in the circular plate that's pressed to the shaft looked pretty boogered up like previous owner just smashed it back on. I went ahead and bought a new Spectra distributor with cap, rotor, and new pip already mounted from O'Reilly's for $90. I didn't want to worry about the old plate coming off, plus by the time I bought a new cap and rotor it would have been almost as much as the whole new unit.

Put in new distributor just now using old cap, wires, and plugs and it fired right up. No CEL. YES! Don't have a timing light so I used a vacuum gauge to get a good smooth idle at about 21." I got new wires and plugs, so I'll swap those later but I was curious to see how it would do with the old stuff.

Thanks again to subford and everyone else who contributed.

Todd

 

Glad to see you got it resolved.

 

I'll update again as soon as we can get back in the garage and work on it some more.

 

It's between the Spectre and a Duralast Gold. In all honesty, I can't believe I'm considering either one, but when your choices are this limited you don't have much choice. I know the AZ distributor has a limited lifetime so that may be the route I take. Looked up the Napa distributors and guess what? Right on the warranty card you can look up on their site, its painfully obvious that they are Cardone units because it says so right on the warranty. They list them as Napa rebuilds when it clearly says otherwise on the card. What a shame. Napa used to be the higher end stuff when it came to box store parts. I did find an Autoline brand from Rockauto, but I've never heard of them.