Ok I'm stumped?

bad12jr · Aug 24, 2011

OK guy my truck is about ready to become part of a bonfire .

I put in ad's , a 17* , and front cover off a motor I bought used. Truck starts and runs like a scalled dog cold. Once it gets to operating temp it seems to lose a little top end from 3/4 pedal to wot. When at full temp it will sometimes die coming to a stop at a light it is very hard to restart and seem like it will try to hit. Did it twice and would not restart. ( Please don't shoot me but I had to give it a small shot of brake part cleaner for it to hit. Was in the middle of the road in traffic). It is also hard to start hot if you shut it off. No matter if its 5 seconds or 15 min. Pulled codes and got some expected codes due to unpluging some sensors. Got a CPS intermittent code which I think is due to the long cranks? Everything else seemed to be odd codes but nothing seemed realted. Clear them and will see what returns.

The scanner I'm using is the torque app on an android phone with a bluetooth adapter. (Still testing but seems to work ok on my truck will post results in a different thread after some more testing) But I got it to pull codes and some datastream. It is a little glitchy but seems to read close to the snap on I used the other day. The numbers seem to be spot on the Snap on at idle and wot but the glitch doesnt give a good flow of data through the rpm range.

DC 14% at idle 710 icp
DC 53 to 60% wot 2400 icp

Anyway it will surge slightly at idle but still has bottom end power. When it does die the rpm will drop below 400 and lose all pedal response then die.

Here is what I've done in order.

Checked oil. (400 miles since changed)
Oil PSI on analog gauge ( 70 cruising 32 at idle)
Swapped IPR from 15* pump ( no change)
Replaced IPR orings ( no change)
Unplugged ICP ( same)
New IPR ( same)
Changed the IPR plug in the harness. (nothing)

My only other thing I can think of is HPOP problem. I think Im going to switch back in my 15* and see what happens. Will loose power but everything else should be normal.

Any other ideas or things to check. I havent checked if the hpop full when it dies because usually in the road.

Thanks guys

twelch3 · Aug 24, 2011

Maybe I'm reading it wrong,but it looks to me like you should try to change out your ICP sensor.Did you top off the oil in the rails after replacing the HPOP?Make sure all of your injectors were properly seated?Loose UVCH connection?

bad12jr · Aug 24, 2011

Have not tried ICP replacement. Unplugged it a couple times hot and cold but no change. From what I read shouldn't unplugging it default to a preset value and eliminate it from the equation?
It shouldn't have any air by now. 400 miles should be enough i would think? Checked them all when I put them in and torqued to the update specs. UVCH are good sorry forgot to put that in. Checked those before ipr change.

SPEEDDEMON31176 · Aug 24, 2011

It sounds to me like you have one or more bad o-rings on injectors. You eliminated the IPR, ICP, etc with your tests. If the HPOP was an issue it just wouldn't run period. I think you possibly damaged an o-ring on install or did you install the injectors without putting new o-rings on them? If new o-rings were they Alliant brand? If you have an oil pressure gauge for the HPO system then you could check each head and see which one has a lower psi which will narrow down the issue.

BWCbuilt · Aug 24, 2011

Did you reburn your chip to account for the hpop change?

neverkickn · Aug 24, 2011

You said you unplugged the icp sensor and it was the same. What do you mean by this? Did it run the same unplugged as it did plugged? If it ran the same then you need an icp sensor but if it ran worse unplugged then that is likely not it.

bad12jr · Aug 24, 2011

New o rings and tuning change. Im getting no smoke at idle or any fluids where they shouldn't be. I think ill try the icp sensor next. And yes it ran the same.

neverkickn · Aug 24, 2011

bad12jr said:
New o rings and tuning change. Im getting no smoke at idle or any fluids where they shouldn't be. I think ill try the icp sensor next. And yes it ran the same.

Then your sensor is bad or there is an open in the wire somewhere for the sensor. Most likely the sensor.

genuineford · Aug 24, 2011

Have you checked fuel pressure?

bad12jr · Aug 24, 2011

Electric fuel with 65 psi when trying to start.

Vengeance · Aug 24, 2011

Assuming the motor you bought is from a superduty, did you use the gaset for the hpop off the old motor or the donor motor, or did you get a new gasket, if so, for which motor.

Secondly, check the icp while cranking when hot to see what it is then.