Cummins Diesel Forum banner

Cuts out comes right back

2697 Views 26 Replies 6 Participants Last post by  bigbluedodge11
Went down to the dyno on saturday at the fall fuel fest. When it was on there it get to about 38 psi and fall on its face and then take right back off. Seems to me its losing fuel or shutting off the fuel. I have a edge that i can turn the back down off. I dont know if this does anything having the XRT on there too. But if i turn the back down off on the edge it on the street it wont due it.

Trucks got the old H&S 225 tune with TSMP8 Air dog 2 and a quadzilla boost fooler. Still got third place on the dynos but seems like my numbers where really low.
1 - 20 of 27 Posts
Is your fuel rail plugged or shimmed? fprv?
It's shimmed I got the MP8. Anyone know if the edge back down would matter if it I was on?

Sent from Free App
Can almost gaurantee you are draining your rail.
I Thought that could be happening. So how do I fix this? CP3?
I Thought that could be happening. So how do I fix this? CP3?
For the money for an aftermarket cp3, I'd just buy a dual cp3 kit...

Also, make sure your stock FCA isn't acting up (Fuel Control Actuator) in your stock cp3.
Is the bag of parts not worth doing? How do i check it out to see if it is acting up? Dont some guys have a fuel rail pressure gauge? Should i get one of those before i start putting parts on.
Not worth doing. First thing I would do is take the MP8 off.
Why is that? For just having the H&S tune i dont think it should be draining the rail
Not worth doing. First thing I would do is take the MP8 off.
I'd snatch that MP8 off and go with EFI Live custom tuning.
I have a feeling that MP8 may be causing the cut out. Give it a shot.
Its worth a shot. think i need to remove it or just turn it down
I personally battled this same thing with my truck, I believe you are overboosting. My map read something stupid like 36.4 boost and would cut out and come right back. I was running an original XRT with boost fooler, I switched to efibyryan and all is well now! cheers

draining the rail is more of a sluggish drop in rpm (correct me if im wrong)
I was gonna try to trade up to a XRT PRO with some new tunes. The edge I have says its hitting 38 psi sometimes even 40. This is not a sluggish drop it dies throws you into the dash and then takes right back off.
That bucking sounds like the FCA (Fuel Control Actuator) on the back of your cp3 pump...I don't know how to check it, about the only way I know how is to replace it with a new one...

I've popped my FPRV (Fuel Pressure Relief Valve) on my rail alot, and it does drop off fast, but mine has never picked right back up and took off immediately following the pop-off.
I took it out tonight and it wouldn't do it? I could wait till it locked in fourth and took off and ran like a champ so idk what to do.

Sent from Free App
This problem was still happening, ordered a ne MAP sensor from genos and that fixed it also think I had my edge set to shut off at 40 psi boost cranked that baby up too and seems to be running good.
I'm glad I ran across this thread I'm having a similar issue with my truck. My truck has a shudder to it and not constant. I was thinking FCA but don't know how to check it or the rail sensor and if there's a way to check that. Was your map sensor running ok just when you fueled hard it have you problems
Ok so that didn't fix it. It's really starting to tick me off. My map sensor was bad for sure. But tonight on the way home a 6.4 wanted to mess around. I took off from about 30 mph and it fell right on its face then took right back off. I've watched rail pressure on a scan tool and it doesn't drop much. Could it be in my tuning? It's only at higher boost it seems like.

Sent from Free App
1 - 20 of 27 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.