Looking for some help figuring out what's wrong with my truck. The truck is a 2001 F350 7.3L Powerstroke.

The current symptoms are that at low rpm it will randomly die. At mid-high rpm (for a diesel) it usually will misfire but keep running. Once it dies, it will usually restart after turning the key off and then on again. It wouldn't restart when I just tried cranking it over without turning the key off first the one time I tried that.

First time it happened I put in my spare CPS (not an OEM) and it didn't help. I've completely used the tank of fuel that was in it and refilled it since, replaced fuel filter and that didn't seem to make a difference. I've since bought the autoenginuity with ford enhancements software to read codes (Thanks to Clay @ riffraff for getting an order shipped same day even though it was submitted after hours) . When I first hooked the AE up it pulled the following codes.

B1352 Ignition Key in Circuit fault
B1458 Wiper Washer Pump Motor Relay Circuit Failure

P0500 Vehicle Speed Sensor A
P1203 Fuel sender circuit failure
P0603 Internal Control Module Keep Alive Memory (KAM) Error.


After playing around some I got a few more codes about Battery voltage but I had drained the truck batteries and so I doubt its related.


None of the above look overly related to my symptoms. So, what do I do next? Couple of thoughts...
1) Clear codes and see what gets stored next time it dies?
2) Replace CPS with an OEM one?
3) Pull, clean and inspect IPR and harness?
4) Other? I'm lost...


Other background...The truck has AIS severed duty intake, banks brake, banks big head, upgraded turbo (GTP38R I think), 4" exhaust, superchips chip, remote starter and security. I recently replaced the up-pipes, CCV mod, intake boots about 500kms ago. The banks brake hasn't worked since but there is a broken wire I need to reconnect and I haven't had a chance to research where it came from (don't think its related but figured I'd mention it just the same).



I really need to try get this running so its trustworthy again within the week as I'm supposed to be taking the truck camping next week. Might have to take it to a mechanic... :-(



Thanks in advance,
TMFS

 

So, after doing a bunch more reading and charging the batteries up I tried a few more things.
1) I cleared codes and fired it up. Within minutes the B1352 and P0500 codes were back.

2) Unplugging the ICP didn't change the misfire. While disconnected code P1280 was set (which is expected) but also P0603 - Internal Control Module Keep Alive Memory Error.

3) When the engine completely dies, sometimes turning the ignition off and on again doesn't get it to restart. Whenever this occurs, the wait to start light doesn't come on, and most of the time the check engine light flashes and I get a bunch of clicking (almost like trying to start a vehicle with a battery that is too dead to crank causing the starter solenoid to click on and off). I used a VOM to monitor battery voltage during one of these instances and though it was around 11.7V this was no different than when the it went through the startup sequence correctly.

4) It really clanks sometimes when it misfires. On a gasser I'd call it preignition.

5) I jiggled wires near the ICP, IPR but couldn't consistently correlate playing with specific wires near the to the stalling though it did seem to stall regularly while I was poking around.

6) Pushing/Pulling on the injector/glow plug harness on the passenger side changed the engine tune slightly but didn't seem to otherwise affect the misfire.

7) I monitored Injector Control Pressure, Injector control pressure duty cycle and engine RPM using AE. They all rise together and stay stable when they should. Small blips occur when it misfires, but they seem to be the result of misfires rather than the opposite. ICP Varied from 725 - 1158 and ICP% varied from 15.62 - 19.53 depending on RPM.

9) I cleaned up battery terminals and ensured good grounding at the battery. Interestingly though I didn't have too much of a problem with starting (under regular circumstances), the starter cranking speed was significantly higher after this procedure.


Would a crappy CPS cause the truck to fire the injectors prematurely causing the knocking I here? I'm tempted to replace the CPS with one of the new Ford ones I've picked up. Anything else I should be looking at? Could I have a bad ground somewhere else such as the computer?

Any help greatly appreciated!
TMFS

 

My suspicions and ideas - and they're all free:

I would pull the Superchips. When in doubt, yank it out. Stock calibrations are reliable when troubleshooting.

CPS falls under the same rule of "when in doubt", but that's assuming you have a spare CPS in the glove box (as all 7.3L owners should).

You could have a bad ground on the windshield wipers. There are many cases where turning on the wipers kills the engine.

Pre-ignition is very bad on a diesel... the forces at play are way more intense than a gasser. You want to nail this quick.

 

Your one code has to do w/ the ignition key...Theirs a wire that runs along the top of the steering column that gets chaffed and causes the truck to intermittently cut off/on. This happened on my 02', theirs a writeup somewhere on it I just forget where it is! To check you need to remove the ignition ( theirs write ups, it just requires a pin ) then remove the plastic cover and the wire runs along the top...this shorted and caused the truck to occassionally die/miss then restart. I will say it's the only time I've seen this w/ any of my 7.3's but hay..it happened!

 

Ok...We're making progress!

Thanks for the help guys. It looks like I had two problems which were only related through my actions. I like to know what I'm doing so I tried things successively one at a time.

First just tried whacking the steering column where I imagine the wire runs that 4EXTRDR mentioned. No change, so I decided to go after the other two items before pulling the steering column covers...

2nd, I replaced the CPS with an OEM ford one. That fixed the misfire/preignition problem. Truck runs much smoother, but still randomly stalled. When it stalled it seemed to trigger multiple random codes (ECM,CMP,ICM KAM, Trans fluid temp, ECM...).

Next pulled the superchips. I've been driving around now for 45mins with no stalling, no codes set, and a relieved smile on my face. I'll put a bunch of miles on the truck before the big trip just to make sure I don't get stranded in the middle of nowhere with the trailer in tow, but it looks good so far. It seems a bit odd to me as that chip has been in it for the 3 yrs I've owned the truck and several years before that with no issues. Must be a failing chip rather than an incompatibility. What do you think Tugly? Would you say its reasonable that a chip could work fine for years but start to fail and cause the engine to completely cut out?

So, I guess the misfire was a red-herring problem I created when I put in the new non-oem CPS. Grrr! Glad I bought 2 CPS's from RiffRaff when I did so I can toss the crappy one and still have a spare (plus my old one which I think is probably still good). My only complaint is the truck is much more sluggish... ;-) Might be time for a tune or four, and not the whistlin' kind if you know what I mean.

Thanks again to both of you for the help!

TMFS

 

Final update...Hopefully.

The truck seems to be running well. I haven't felt or heard it miss a beat since I pulled the chip. Just to be sure I'll put the chip back in at some point to confirm that it causes the problem.

One other thought...What are the chances that there is some other weak point (ie a weak hpop, poor PCM ground or something) that is just not up to the extra demands placed on it by the chip?

Again, a big thanks to you guys for the help and to Clay at RiffRaff for making such an effort to get the AE out to me so fast. If for not those two, the truck would be sitting in the shop as I type.

TMFS

 

It's very possible re-installing the chip will give you no problem at all. I lost track (long ago) how many electronic issues I solved just by "swiping" the cards. This is a process where you remove the suspect card and re-install it - thereby swiping the contacts and making a fresh/clean connection.

Kudos go to you for getting the right stuff to muscle through something like this, and for not being afraid to "neuter" your truck.