Hey All,

Just installed my 4kGSK tonight and just have a few issues with it. Took it out for a test drive and the throttle touchy but the thing that is frustrating me is up around 2700 RPM or so it starts to stumble and miss.

Thats all for now.

Thanks.

 

Sounds like your running out of fuel.

 

Is my pump just too small then? Shouldn't i have enough fuel with the mods that i have done? The truck will still rev past 2700 rpm but i dont know what this sound is so i havn't really taken it past that point. It doesn't feel like it looses much power like it would before when i would start to hit the govener with the stock gov springs in it.

Could this be cause by timing?

 

I m wondering about the valve springs? Its a 94, so I guessing they are oem still and maybe pretty well used?

Since doing my 4000gsk I could easily run to 3300(oem 98 springs) then when I did the 60 ib valve springs for the E brake, I have run it to 4000 no noises, no problems.

 

Thats another thing i've thought of, the truck only has 113k on it so its not like its a high mileager. Planning on installing the 60lb springs next pay check

 

my '97 with just shy of 230k on the stock valve springs revs to 3400+ often

go to your local parts store and get a cheap double throttle return spring set from the "HELP" section... made a HUGE difference in pedal pressure/throttle response... not so "touchy" anymore!!

not sure about the stumbling/sputtering

 

I can deal with the touchy throttle only thing thats making me worry is the stumble/sputtering.


Another thought, could it be the wastegate? I've never been in a truck thats hit the wastegate before so i'm not sure what it sounds like.

 

I don t think your waste gate is the problem, but you might want to try blocking it anyway. I ran mine for awhile with no waste gate, just disconnect the line from the afc and put a pipe plug in the afc. You don t need to do anything to the line going to the waste gate, it will no longer get a boost signal so the gate stays shut. You could see 30-40 psi but I never did cause Im at the worst place on the planet for air.

113k isn' t much....I wonder if the valve springs were changed from early years?

When you do the springs, do 6 first....then 5, cause after you ***** and swear at them for awhile the rest will seem real easy.

 

Alright, suppose the only way i'm going to figure this out is to throw parts at it

Its starting to sound like its the valves from everyone else here so i'll go and buy some of those Tuesday and get them installed eventually, anyone have a good link that explains in detail how to do it?