Engine/Transmission (1994 - 1998) 12 Valve Rough running

[MM800]

I have a 98 12 valve with 300000 miles. I've installed a #10 plate. m Every thing seemed good. Then I instaled a 3000 GSK kit. It seams to stumble when you mash on the throtle. I tried ajusting the springs according to PDR spec. after orginaly setting springs to micrometer. One light click and then two more after. It acts like the engine is cold at operating temp, (150). It's that kind of stumble. Timming is at 15. 5. I instaled a B-1 turbo with a 4" down pipe. Now my temps have gone through the roof and lots of black smoke. Moved plate back to get rid of some of the smoke. Power is down now, not as good with stock turbo. Turbo seams to not be comming up quick enough to match fuel. Really have to get into the throtle to get high boost. By then temps are too high. Found turbo leak but still is not right. At 75 mph 2100 rpm 7- 10 pounds of boost. some times boost comes up, stumbles then takes off. Replaced fuel pump. No difference. Exaust temps are getting too hot before boost is achieved. Any sugestions would be greatly appreciated.



Thanks

 

[Rams-n-Hogs]

Did you try moving the AFC housing forward, and adjusting the starwheel?



Jim

 

[MM800]

would this cause the rough exceleration even when it is not under a load?

 

[Rams-n-Hogs]

It will cause mine to hesitate when I pull it back. You might want to also check the adjustment on the governor lever. I helped a friend put a set of springs in his truck a couple years ago, with a #10 plate, and that's what the problem turned out to be on his truck.



Jim

 

[MM800]

I tried moving the afc housing forward. It was all the forward already. Next I tried moving the star wheel. more smoke , better on the low end. When I nail the throtle it still stumbles. Like the timming is retarded and I 've got bad fuel. Seams to come up on rpm if I don't nail it



Thanks

 

[MAleksandrowicz]

how old is your fuel filter?

 

[MM800]

New!



Thanks

 

[Signal73]

Ever clean your fuel heater strainer?

 

[MM800]

No, good idea, thanks , if it works , frankly the beer is in the mail!

 

[Vaughn MacKenzie]

When did you set the timing? Was it already at 15. 5 or did you do it with the GSK upgrade? It almost sounds to me like it slipped.

 

[Matthug]

I'm with ramsnhogs, governer lever.

 

[Signal73]

Here is the instructions to adjust the Lever if nothing else checks out. Be careful not to back the adjustment screw too much it will fall off and drop into the pump.

 

[MM800]

Thanks guys , I'm going to try the fuel heater strainer and then the govenor lever. When his thing is right I will be sending out one of the finest bottles of Scotch I can find to the Winner of "Why Does My Truck Run Rough".



Thanks

 

[Smokin_Monster]

governor lever? What was the problem? I just installed my 4k gsk today and I have the same stumble at high rpm.

 

[Matthug]

Smokin monster your problem is probably because of valve float since you installed the 4K springs. The stock springs can only handle 3400 RPM or so, you need 60# springs to go higher.

 

[Smokin_Monster]

Sorry I forgot to mention I did the #60 springs too. I also changed to fuel filter. That only helped a little. It still stumbles a little as I approach 4k rpm.