Hey guys, I need some help with my truck. I’ve done some searching and can’t seem to find anything that matches my exact scenario. My truck now has almost no power, runs rough, and has a helluva time starting…

My truck started having a tough time starting in February (nothing out of the ordinary for the cold winter). It would only start when I had it plugged in. I didn’t think much of it but was annoyed since I replaced all 8 glow plugs in September (and put in the 50 cent mod). Buzz test and glow plug test are good. But once it started and warmed up, truck ran great and had all the power I would expect.

Then about 2 weeks ago the starter went on my truck. I replaced it and when I started it up and drove off, it had no power at all, acting like the turbo was seized but I could hear it whistle so I know it’s still spinning. I disconnected both batteries to replace the starter so I didn’t get showered with sparks so all I could think was that the computer needed to re-train itself. After driving a while, the problem only seemed to get worse. Now I can’t even pull out onto my street when traffic is near because it takes forever to get up to 40.

I seemed to remember that last time I pulled the IPR out and cleaned it and galled up the inside screw that holds the internals together and though it ran fine after I re-installed it, I figured it was only a matter of time that I replace it. Wasn’t sure how that would have been effected by the starter change, but it was something. So I immediately went to Ford and got an OEM Motorcraft IPR and put that in. No Difference. I also did a full oil/filter/fuel filter change before putting the new IPR in. And as an fyi I also replaced the ICP sensor back in September since the connector had oil in it.

I noticed sometimes when I’m full on it and it’s slugging away to slowly build speed the O/D light starts to flash (tranny issue?) but then stops flashing after a minute. PCM Issue? I tried to pull codes but my OBD 2 scanner didn’t show anything. I’m suspect that it’s not connecting because it won’t even show the VIN #.

So my big question since this all seemed to happen when I changed the starter is how many miles do I need to drive before the Computer is straightened out? Is it possible disconnecting and reconnecting the battery fried the PCM? Seems strange to me that a truck that ran so well (when it was warm) would then run so horrible immediately after replacing the starter?

Truck Info: 2001 F350, 7.3L, XLT, 4x4, Automatic, Bone Stock, 247k miles.

Thanks in advance!

-Jon

 

The PCM (computer) is probably ok. It does not relearn anything important to operation after losing power. Will set a P0603 KAM code but that will not cause a CEL. Do you have the CEL on now?

I'm leaning toward a sticking bendix on the starter. If it stays engaged it will be a substantial drag on the motor. Next time right after you start it get down there and whack the starter with a hammer. The goal is to jar the bendix free from the flexplate. Then take advantage of the warranty on the starter.

Few code readers work on 7.3s. But if you have an android phone you can run Torque Pro app with a Bluetooth ELM 327 obd adapter. If it's not the starter the next step is getting some sensor readings to see what she's doing.

 

Thanks, the engaged bendix makes sense but it doesn't quite feel that way. Every once in awhile when I ease into the throttle just right i'll get a momentary surge of power (like 2 seconds) and then it goes right back to being a dog. But it's rare that I can make this happen. I'll give the starter a whack just for kicks, hell maybe it'll make me feel better.

Does the Elm 327 also do the buzz test and glow plug test with an android app? I think I'll get one so I can look at the sensor readings.

 

This is a really off the wall thought, but another member here had an issue with an ever so slightly failed alternator putting out an A/C signal which affected his trans. Did your starter fail electrically? Possibly damaged a diode on the alternator and some wonky A/C signal is gumming up the works. If I can learn how search from the phone I'd find that thread. But I think it was either Y2KW57 or Pikachu...

 

It's by Y2KW57, posted a year ago "Rebuilding a Ford 6G Alternator". No clue how to link it here. And it won't help you now, but wondering if the issue he had could be your issue, just a different symptom?

 

I guess a check would be to start the truck without the alternator connected, see if it runs better. Remove the serpentine belt and run it off the batteries for a few minutes?

 

Someone who hasn't been sitting at an airport bar for the last hour waiting for a delayed plane drinking beer might pop on here soon and offer more sound advice.. hiccup.. Okay, I'm done.

 

If your starter was staying engaged to the flexplate, then it would have failed VERY quickly after driving it. I would start with reading the codes. Is your CEL light on?

I wouldn't rule out SaintTC's idea, but I'd keep it a little further down the list until you do some basic troubleshooting - i.e. get the codes read. If you have an iPhone/iPad, there's an app called forscan that you can use with an OBD-II to wifi adapter. Some people find it a little more useful for troubleshooting than Torque Pro.

 

Maybe a ground? Did you happen to change the fender mounted starter relay at the same time?

 

I did change the fender wall starter solenoid but I'm not sure anything went wrong there. The new starter cranks way faster than the old one and appears to have good connections which I would think means the 12V and Ground from the battery are making good contact to the full electrical system.

It does seem clear the more I read that this will be tough to diagnose without pulling fuel and oil pressures and other sensor readings. Researching Bluetooth OBD connectors, do I gamble and get a 12 dollar Elm 327 or spend $80+ and get a good quality scanner? I'm not trying to go into business working on 7.3Ls and not trying to tune the thing to brand new status, just trying to get my truck fixed for the time being. Thanks again guys.

 

When faced with the decision of the scanner I went with the more expensive one that would reliably read every vehicle I owned. Not to say that the POS $12 jobby won't get it done, I wanted something that I knew would be there for years to come.

But, I also shop at Harbor Freight for some BS tools too.

 

So apparently the fix for my problem is to click 'order' on a new scan tool and that's it. Just like that, truck runs great again. I can't imagine how the truck went from running so well, to running like garbage the second I started it after replacing the starter, and then all of a sudden it runs fine again. Seems like the computer needed an exact set of miles or hours to run after re-connecting the batteries to 'switch' back to normal mode, but I've never heard or seen anything to back that kind of functionality up.

Still going to checkout live data when the scanner shows up. If there's anything out of the ordinary i'm sure i'll be back. But figures, the problem always goes away right when you (or a mechanic) goes to take a serious look at it. The scariest of all situations.

 

I would definitely say your problem is not solved. You probably have a loose wire or short somewhere. Some common areas to look at are the UVCH connectors (have to pull the valve covers to inspect the inside) and where the 42-pin connector rests on the driver's side valve cover. Have you done the fifty-cent mod?