LLY: breaking up at 4k

[duratothemax]

I have LLY's and LB7's with 250% injectors that regularly turn 5000+ rpms

Yes tony, but at what pulsewidth....

pat is saying that, regardless of injector size, a duration longer than 3000us, with the crank spinning at 4,000rpm, you'll get overlap.

I know you're not going to tell us what secret magic pulse width you use, but I guarantee its not 3000us with 250% injectors.

 

[Dan@PPE]

I have LLY's and LB7's with 250% injectors that regularly turn 5000+ rpms

Yes tony, but at what pulsewidth....

pat is saying that, regardless of injector size, a duration longer than 3000us, with the crank spinning at 4,000rpm, you'll get overlap.

I know you're not going to tell us what secret magic pulse width you use, but I guarantee its not 3000us with 250% injectors.

The size of the injector is not the issue, the pulse width at RPM is...

 

[juddski88]

Is it something that happens over time to fatigue the ficm? Say for guys not running motorsport nozzles who runs longer pulsewidths?

 

[Dan@PPE]

No i dont feel it has anything to do with time. The truck I posted in the video has less than 3500 miles on it.

High RPM and High pulse width (over 3000us) will cause this.

 

[duratothemax]

The size of the injector is not the issue, the pulse width at RPM is...

Dan thats what I just said.

 

[Dan@PPE]

That was ment for Tony.

I know, that is why I quoted you...:hug:

 

[juddski88]

No i dont feel it has anything to do with time. The truck I posted in the video has less than 3500 miles on it.

High RPM and High pulse width (over 3000us) will cause this.

I asked because the OP hasnt had this issue forever...which is why it is most likely a crank signal issue like Ben said. But those of you who suggest it is pw and rpm related keep going. Maybe a new thread in the tuning section?

 

[jdlover1]

yea this issue just started in may. So its not in the tune. Thanks for all the advance tho guys

 

[GMC_2002_Dmax]

I always recommend to my customers when they are running too much PW for what is needed to increase injector size to keep PW low and timing lower.

It was a few years ago that I tuned the truck and it has just acted up which probably means after two years it's not tuning related and is most likely sensor related.

I don't have magic, anyone can log what I do.........it's just not that easy to duplicate with a log what is actually done in the tune......:rofl:.......those add on tables and multiplier tables and limit tables all have to be right.

:thumb:

 

[jdlover1]

http://youtu.be/qWSQ30gK1mk

I found out what the problem was. Crank sensor bolt had worked its way out. Put new bolt in and replaced sensor just to be safe. Thanks for the help guys

 

[Dan@PPE]

Good to hear!:thumb:

 

[chevyburnout1]

Love it when its something simple!