hiccuping in hotter tunes

[joe d]

So this is new to me truck never did it before.:fustrate:
Truck has 238/100
T4 billet s366
Built trans
3in intake plenums
And electric fuel.
Stock hpop

In my tow tune i can put it on the floor and it just runs smoth and strong...
If i put of in a hotter tune it acts like its cutting out or maybe running out of fuel? The hotter the tune the more it does it. Kinda like on off on off or a rev limiter but its not that. There is no boost fooler on the truck im under the impression that the obs will not defuel do to over boost im not sure if im correct on that. And ive never had a cel go on. No codes.
Im completely lost and before i dig into it to deep. I wanted to ask opinions.
Thanks joe

 

[outlawpowerstroke]

Hpop might be gettin weak and not able to handle the amount of fuel bein pushed


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[joe d]

I was thinking that but i would get a cel i would think? And ill be looking at hpo today or tmr as soon as i have time to get the ae out and datta log a few pulls.

 

[sootie]

check ICP

 

[joe d]

Thats the first thing on the list last time i logged data was in a tow file wot run held 2800 at like 46% sure as hell saprised me. Its allways ran good and pulled hard for a stock pump.

 

[joe d]

Anyone else have any opinions? Seems were all thinking hpo but i get no cel... I thought it would throw a code

 

[ghohouston]

Fuel pressure?

 

[joe d]

Never moves from 68 on the gauge thats what i thought.

 

[Garbage_Mechanic]

Different years and PCM codes are different. My 96 has the on/off/on effect with overboost you are describing. Scared the heck out of me the first time it happend, passing a 6.0! Thought I blew it up... Bolt on a boost regulator and no more problem.

 

[joe d]

Okay im going to look into hpo with ae today im hopeing. Ill see if i can make or get my hands on a boost foller.. I was under the impression the obs did not defuel at all? Thanks for the input yall.

 

[Garbage_Mechanic]

"I was under the impression the obs did not defuel at all?"

This is another one of those internet "facts" that isn't true when you get into it. Some PCM codes don't defuel. But most do. If you search the Diesel Stop for my posts back around 2004 or 5 you will see where I found out the facts.

Put a pressure regulator on the MAP line. It has been a long time but I think 27 psi is the trip point and I have mine set at 24. It has been 10 years so look it up before relying on that.

If you want the details ask Jonathan, Bill or Jody....

 

[joe d]

Thank you. I will put one in there asap to do a quick test would it work if i just took the map line off for a pull or two or would that create other issues.
Thanks

 

[Garbage_Mechanic]

No map line connected results in low fueling because no boost seen, no fuel means no boost exceeding over boost shutdown point so you can't test that way. It will not over boost because it will not get fuel. Have to put on the regulator.

 

[joe d]

Okay thank you.

 

[kip4234]

If you rule everything else out, my 96 did this with a different set of injectors that had just been purchased from one of the name brand builders here on this site. after exhausting every other option in the world they finally sent me a new set of injectors and all was fixed. they later told me that they assembled some of the injectors with B code internal springs and some with regular springs and that was what had caused this.

 

[joe d]

Ok will keep in mind

 

[superpsd]

If you rule everything else out, my 96 did this with a different set of injectors that had just been purchased from one of the name brand builders here on this site. after exhausting every other option in the world they finally sent me a new set of injectors and all was fixed. they later told me that they assembled some of the injectors with B code internal springs and some with regular springs and that was what had caused this.

How did those run and idle. Those springs are about 1000 psi difference in VOP. I imagine they would have ran like crap

 

[kip4234]

The idle was fine and in stock tunes it was fine. Every higher setting on the tunes got worse it would run like a gasser starving for fuel in higher chip settings.

 

[joe d]

Okay so did boost fooler.
Fuel psi gauge brand new psi holds solid at 68.
Installed hpop gauge hpo is at 2800 or so and holds pretty well. Any other thoughts thanks. Joe

 

[joe d]

Littel update i lowered boost fooler down two around 22 psi and it does not do it anymore. Thanks to all for the help and i wanted to make sure i finished the thread for the next guy...