Car stutters at 100% throttle

[srpjosh]

Here's the problem. When I stand on the throttle and it's at 100% the car stutters. I can get into throttle slowly, hit boost, then full boost no problems, at 99% throttle no issue. Did a boost leak test, no leaks. The issue only happens at 100% throttle, not at a boost level. As soon as it hits 100% it starts stuttering? No CEL. Any suggestions?

 

[black_gst]

i used to have a similar problem on my gst... i couldent figure out what it was but once i got ecmlink it disappeared.. i just figured it was a hole in the fuel map.. too much fuel too fast so the car bogs from being super rich.. do you have a wide band? or logger to see if this is whats going on

 

[iluvmy4g63]

at what RPM is this at? what PSI? do you have a good boost gauge? shutter like mis fire. or like shutter from fuel cut for lean out.? whats your spark pugs gapped at?

need more info to help out bud......

 

[rocafellafw]

Does it happen at any boost level and any rpm as long as it's 100% throttle ?

 

[Defiant]

Plugs and wires.

 

[solidviper89]

I had a similar problem!
My problem was a simple o-ring at the fuel pump. I have a walbro 255hp, finally changed it this past weekend and it made a world of a difference!

 

[srpjosh]

I have a wideband and Logger. The wideband reads normal based on rpm and boost level when i stand on the throttle. I see nothing wrong when it's happening. It happens at any psi and at any rpm. I have a Autometer Cobalt boost gauge and MSD 3-Bar MAP sensor. Plugs are new NGK BPR7ES, gapped to .32. I can run my car to 7k at full boost no problem, i just can't stand on the throttle. I can run 80%, 90% no problems.

 

[jjgrizz73]

Mine is doing the same, it stutters only at full throttle at high RPMs in 2nd-5th...its sort of pops, quick multiple hesitations. Is that kind of what you're getting?

You might want to gap your plugs down a bit to atleast 0.026-0.027

 

[solidviper89]

Mine would pop and pull the timing, I fixed boost leaks, I changed wires/plugs. The car would jerk and not do much it was really annoying

 

[srpjosh]

After checking all of he usual suspects: plugs, wires, boost leak. I checked the tune. I use the SAFC-II, and changed some settings due the atmospheric changes occurring with the season change. Did a re-tune, fixed the issue.