The Diesel Stop banner
1 - 12 of 12 Posts

·
Registered
Joined
·
54 Posts
Discussion Starter · #1 ·
If been having this stumbling issue with my truck for a while. When it shifts into O/D it stumbles and it only does it in O/D. I have a dp tuner and it does it in every setting. Most noticeable in stock. Fuel pressure is good, icp is new I changed my Hpop to a 17 because I had a 15. And now it does it even more? I got the code P1211 randomly with my 15. Now when I start it the truck runs for a fewsecs and instantly sounds different and I get the code. It runs more rough with the 17 pump as well, I'm assuming that's because its moving more oil faster and the issue is more noticeable now. Any ideas on what to look for?
 

·
Premium Member
Joined
·
3,754 Posts
Where did you get the new ICP from?
My guess is the ICP is a failure and or the pig tail needs replacing.
Also check the coil on the IPR or tin nut.

unplug the DP chip and try .
 

·
Premium Member
Joined
·
2,197 Posts
do you have something to monitor your ICP?
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #4 ·
Icp from Riffraff diesel. IPR is good. From what I've read the ohms are good on IPR. Just tore it apart and cleaned it as well. How do I measure and see if I need a new pigtail?
 

·
Premium Member
Joined
·
2,197 Posts
any oil in the pigtail?
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #6 ·
Icp 790psi.
Icp duty cycle 11.33%
Icp volts 1.13v - at idle

Icp 1900psi
Icp duty cycle 22.28%
Icp volts 2.58 -at half throttle (roads are icy out here, kind of hard to do WOT without my a$$ end coming around)
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #7 ·
No oil in pigtail.
 

·
Registered
Joined
·
2,846 Posts
Remove the dp tuner. Just to rule it out.

Did you try changing the cps? They will fail and cause random issues.

Also in rate cases low fuel pressure will throw a p1211. Check fuel pressure under load
 

·
Super Moderator
Joined
·
26,503 Posts
Also in rate cases low fuel pressure will throw a p1211. Check fuel pressure under load
Good idea. (I think spell check got him - probably meant rare)

The IPR duty cycle numbers don't look out of line, although ICP it pretty high at idle. Should be in the 450-550 range. Maybe there's a high resistance connection that's biasing the ICP signal.

Also check the wiring harness for chafing/shorting against something.

Does the SES light come on when it stumbles? Kind of hard to notice if it's momentary.
 

·
Premium Member
Joined
·
4,341 Posts
Icp 790psi.
Icp duty cycle 11.33%
Icp volts 1.13v - at idle
Was your idle after the engine had warmed up?

My ICP looks like that at idle when cold.
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #11 ·
No the SES doesn't come on when it stumbles, it just always stays on. Those numbers are when the engine is warm. What should my voltage be at the icp harness if I'm testing it? Fuel pressure at idle is 62psi.
 

·
Registered
Joined
·
54 Posts
Discussion Starter · #12 ·
So update. I looked at my IPR and the tin nut was gone. It was there this weekend! I had a spare IPR that I tore apart and cleaned up and put that one in. Also for the hell of it I changed my cps. I had the blue one in so I took it out and put the gray one in. Ses light isn't on anymore and truck runs a lot better. But...driving home I was going down this big hill because my turn was at the bottom, just before my turn the ses light came on for about 5 seconds then went away. At the head of my icp plug I can see on all three wires a little insulation is missing (I can see the copper on all three wires). So maybe change the harness and hope for the best?
 
1 - 12 of 12 Posts
Top