Interesting Problem

lincolnlocker · Jun 4, 2012

kyle43335 said:
i ran into that as well.

ive also had a truck run weird when,and only when it rained.

turned out the female cavities were loose in the cps plugs.

i used a awl,to squeeze them tight for a good solid connection. straightened the truck right out.

come to think of it i had this exact problem with the icp sensor.. truck would run funny, even die... started back up and started wiggling conections, wiggled the icp sensor pig tail and the truck died.... did the same as you. never had a prob sence.

bluedge8 · Jun 4, 2012

did you see beans thread on rotella? just posted today. I'd change the oil and see what happens.

Hotrodtractor · Jun 4, 2012

bluedge8 said:
did you see beans thread on rotella? just posted today. I'd change the oil and see what happens.

I promise - I have refused to run Rotella in these trucks back in 2004 when I realized it was crap. LOL This truck has quality oil - but I'm going to change it because although there isn't a lot of time on the oil - it was put in at the end of last season.

ford_trck · Jun 4, 2012

Jason what is the battery voltage? I had 1 dead battery on my truck and it was causing some interesting issues. If your pressure's are looking good maybe the issue is elsewhere.

Hotrodtractor · Jun 4, 2012

ford_trck said:
Jason what is the battery voltage? I had 1 dead battery on my truck and it was causing some interesting issues. If your pressure's are looking good maybe the issue is elsewhere.

Its been running a little low, but not bad - cranking is something like 11.6-11.9 - running seems to be 12.9 to 13.9 depending on how dead the batteries are. We have been cranking on it a lot trying to get it started and keep it running - we had a tuning issue with the ICP that was a hold over from some other modifications - so the truck was dying when the ICP would drop because of the reaction setup in the tuning for the ICR - I went out there to put this new tuning on the truck - took it out, tested it, everything was fine - then BAM - died while it was sitting there idling while we were BSing.

907DAVE · Jun 4, 2012

Any AC voltage in the charging system?

Getting a 605 or 603 code?

TARM · Jun 5, 2012

Have you actually checked the HPOP itself? The shaft?

Dieselboy. · Jun 5, 2012

Did you ask it nicely ?

Maybe it just doesnt like you LOL.

CPS with a combo of HPOP somewhere ? Head rail O ring ?

DZL JIM · Jun 5, 2012

Correct me if I'm wrong, but the truck should start and run with ICP unplugged, so if it's not I'd start there.
?

TurboM700 · Jun 5, 2012

Had a truck in the shop last week that was doing something very similar to this and I ended up replacing the valve cover gaskets and it fixed the proplem. The left bank wiring was going bad causing injectors to turn off and stay off enough to slow the RPM down and the HPO would rise.

Just something to check.

Hotrodtractor · Jun 5, 2012

DZL JIM said:
Correct me if I'm wrong, but the truck should start and run with ICP unplugged, so if it's not I'd start there.
?

I already tried to unplug the ICP sensor - it then uses the default ICP tables and attempts to fire the truck - similar result to before - its hit or miss - but it is very obvious that the ICP sensor is working and working correctly.

Also - harnesses are fine - when it runs it runs great - always passes a buzz test and you can here all the injectors firing very promptly and sharply - nothing lazy or dull sounding. I even ran a buzz test, started the truck, and immediately ran a buzz test the moment it died. Its worth noting that it would not start after it passed the second buzz test - so I know its not the harnesses - and even if one of the wires were bad - it would still start and run and run rough on at least one bank of cylinders.

Big Bore · Jun 5, 2012

Hotrodtractor said:
Sometimes - it just doesn't build ICP pressure turning over - it only gets up to 350-400psi - but other times it cranks the ICP right up through the roof and starts right up.

We had this same problem when doing a motor swap last year. We swapped IPR's and it went away. I've had this problem other times and I've given it a shot of ether and it would fire and run fine, and restart later. We both know if ICP is down it's the IPR either sticking or getting bad signal. Sometimes I think it may be a transient signal thing.

A thought I just had, does EOT affect the IPR at all during cranking and starting?

lincolnlocker · Jun 5, 2012

think he mentioned earlier that it starts in the morn and idles til it warms up, then dies. i would think eot does have a roll in it. thats if in fact the ipr is the culprit.

Big Bore · Jun 5, 2012

I think a hot IPR can stick also. I wish someone would figure out a way to completely disassemble and recondition an IPR back to spec. $200 a pop can get pretty spendy. I'm still trying to figure out a way to put a filter on my dual IPR block.

lincolnlocker · Jun 5, 2012

HRT, any progress today?

Hotrodtractor · Jun 5, 2012

lincolnlocker said:
HRT, any progress today?

Nope - I got home from work about 30 minutes ago - and the truck isn't at my shop its at another. Tomorrow night is the plan.

lincolnlocker · Jun 5, 2012

got ya!

TARM · Jun 5, 2012

Ok so a run down

ICP sensor has been ruled out
Wiring has all been checked out OK
Buzz tests comes back fine
LPOP pressure is good?
HPOP Res level good?
Have you swapped out the IPR or broekn it down?
Have you swapped out the CPS yet?

If all of the above are checked as good this is the only issue I have come by that fits:

I know of situation where the HPOP shaft would slip or not otherwise turn properly and that cuased the EXACT situation you have described.