turbos10

Most likely you had a piston at TDC exhaust stroke and had some valve overlap allowing bypass.....or an exhaust valve leaking at the seat, but I would bet on the first.

GAmes

The springs are the same for intake and exhaust. I got mine from Cummins. $100 for a set sounds like a good price if it was all 12, and may be for only 6. It has been quite awhile since I bought mine.

Racing_Joe66

i will have to check on getting some, before i have problems. i will call up the place i got the GSK kit from and see what they have to say. maybe they will cut me a little deal since he thought it was only the EX that was needed.

i have checked and i have no boost leak. the cruising boost is like it always has been when pulling loads.

its just very very odd that in OD i can't get it past 23-26. before i did the GSK and IC and ELEC FANS i could always and i mean at any given time get it maxed out at 35 psi. now the only way i can get close to that is turn the OD off and i can get it to 30 maybe 32.

i just don't get it. and i can notice the power loss when the boost level just stops. once i get home i will have to do some serious testing.

Racing_Joe66

nobody has any ideas?? ok this is what i have noticed:

I TURN THE OD OFF---
and have a ton of power
gain boost like i should MAX 32/33 psi
increase speed VERY quick
exhaust temp keeps climbing to the 1500* mark

I TURN THE OD ON---
and loss power
alot less boost 22-24 psi max maybe 26 if i am very lucky
barely gets up and goes
exhaust temp won't go past 1,150* no matter what.

i am just wondering could it be that the tranny is locking into OD too soon and not unlocking out when it should at higher speeds?? could that be causeing this?? i think i am going to take it to DAVE GEORAND tomm and have them change the tranny fluid and take it for a spin with his computer hooked up and see what he can tell me. i want to say that might be my problem. but i am no expert on that field. but it sounds like it could be the cause.

thanks

turbos10

I just noticed the GSK thing. Sounds to me like it has changed the fuel curve as opposed to what you are used to. It may not be fueling as hard in the lower RPM range. This would make it more sluggish and less boost with converter locked in OD since you can not get RPM up as quickly.

Just a thought.....

Racing_Joe66

ok. thats another thing i was thinking too.

the fuel plate is all the way forward. but the AFC housing is all the way back. if i move the housing all the way forward should that help?? and should i maybe adjust the starwheel??

thanks

turbos10

Star wheel should not effect fueling at that boost level. As mentioned earlier in the thread, the AFC all the way back can keep the gov arm from contacting the plate if it is full forward. I would move the AFC at least to the stock position.

Racing_Joe66

weres stock position?

turbos10

Somewhere in the middle....if not marked, I would start in the center. Someone else will have to chime in if there is some set way to find the stock location....

GAmes

First of all, the GSK will not change your fueling curve, it's only function is to allow the engine to rev higher than the stock governor springs would allow. AFC cover could change the RPM of initial fueling. With the fuel plate full forward it would make sense to push it full forward as well. Star wheel settings will give you initial fuel burst off the line. All the way forward will give you lots of smoke (wasted fuel) at low RPM. At what RPM is overdrive locking at? If it is below 2000 or so and you are loaded you are just bogging down the engine and it is operating normally. If you are above 2000 and accelerating then you have maxed out how much fuel that can be delivered.

turbos10

If the GSK can not change fueling, then why is it that everyone reports a GSK to fuel harder than shimmed stock springs? If they only limit max RPM, why can it change low idle by changing the other springs. Considering there are multiple springs with different rates and there is a transition between them, it sure seems to me for an opportunity for some defueling....but, I am no pump expert.

BigErksG2

i would put the afc housing all the way to the front of the truck.... with it all the way towards the cab you most likely arn't even getting near your fuel plate.

GAmes

Everyone??? The GSK allows the engine to get fuel at a higher rpm than stock, period. Perhaps that is what they mean by fueling harder. Idle changes because the spring rate is different than stock so the flyweights change the position of the fuel arm slightly. When I installed my GSK my idle rpm dropped about 100 from stock. The only other difference is that I can now power all the way up to 3300 before defueling, opposed to the 2700 that was stock. The fuel curve is a function of the plate, I didn't change it and of course there was no change.

turbos10

Okay, if it is simply a top end fuel limiter, why are there three springs? Again, if it only changes high idle defueling, then why did it change the fuel arm position at idle? Not saying it is not that so simple, but it is not how it has been explained to me. I believe there is some involvement through the RPM range particularly if spring rates are off or out of adjustment. Possibly this is the function when properly adjusted, but when out of adjustment it interferes further.....

I bring this up because I really would like to know the total possible involvement in fueling and I believe it to be less simple than high end defueling. My truck has some strange fueling tendencies with shimmed springs such as higher fueling at part throttle and a surge of fuel (asssumed by smoke) when lifting from full throttle. It could be a combination of plate position and AFC adjustment, but other internet experts(I qualify this because there are some not so expert experts) have told me it is the shimmed springs causing irratic fueling. I dont want to buy a GSK and find it is not my problem.

BigErksG2

the reason your idle can change slightly is because if you are even a hair off from where the stock springs are your idle will change accordingly. a hair loose = lower idle, a hair tight = higher idle. some people go tighter in order to get a few more rpms up top but they also have to deal with a high idle. one thing that may cause your fuel curve to change is if you to the washer on top of stock springs deal instead of getting new springs.... gsks are precisely researched and machined, washers, not so much.