This isn't really a problem with the engine. It is doing everything that it is supposed to do. Defueling is a condition that the governor creates to prevent over reving as determined by the governor spring. A 3200 rpm governor spring is a cheap fix for getting up to speed. If you want more than that you will need to replace the valve springs to prevent the valves from hitting the pistons.

 

Kind of an old post, but I have been busy, Just verified that fuel pressure is ok on my truck, so I'm a little less concerned about having a possible faulty pump. It's high idle screw time, gonna do some research and hopefully do something about it this weekend.

 

Crossy's son- got a pic of the throttle limiter screw location? Sounds lke I need to check on that one. Much appreciated
And, to stay on topic, I, too have the same 4:10 gearing and howling at anything over 75 mph. Have the 3200 spring in, too.

 

Matter a fact i do !

EVERYONE NEEDS TO DO THIS SIMPLE ADJUSTMENT! if you own a 3spd auto truck with 3.07 rear and you're tired of going 80mph max and want to go 95+...take out this screw.

With tamper proof cap-



After some tampering is done to the tamper proof cap-







With the screw backed out and the front of the throttle linkage hitting the fuel line (i ground off that useless little knib on the front of the throttle linkage that will hit your fuel input line)



location-

 

Whats with all the red? don't wanna show your custom throttle settings?

 

I had that picture edited to show that my little heim join end had broke a long time ago, different use for the picture now so i decided to cross it out so it didn't grab attention.

 

Crossy Jr.-Thanks. When I get home I will look into it. What tools/methods did you use to remove the tamper resistance device? When it is all said and done, is it still possible to put it back to oem, other than the the tamper device?

 

Yes you can simply run the screw back in for the OEM appearence and function.

As for the tamper proof cap, i put some channel locks on it and used force to rip it off, its really on there. its just thing alum. though so it'll usually pop right off if you just put the pliers on it and shake it back and forth vigourously.

 

Crossy Jr., do you think this is the reason why even with a 3200 spring, power pin adjustments, aftermarket afc pin, injectors, etc,(see sig) that my isspro tach only shows 2300 max at WOT? Is this the missing link? Seems that everyone in my area w/st gens that did the 3200 spring hit way higher rpm's than I do.

 

Something is not right. Are you sure your tach is correct? Are you getting full throttle on your linkage? Is your throttle lever indexed correctly? I can turn over 3 k with both of my trucks with a stock spring.

 

GV core swap/rebuild is $800. The design life is 250k mi. So depending on what's wrong with the rear, it will certainly end up costing more to get the rear rebuilt, or maybe about the same if you do the work yourself. GV r&r is an easy hour's job under the truck, no special tools required.

 

"After some tampering is done to the tamper proof cap" --->
I LOVE that statement, made me chuckle. It's raining outside right now, but Im hoping it'll let up so i can go back out my screw and see what that does to my freeway cruising speed, Words could not describe the happiness I will have If i can get my truck to comfortably drive at 80mph ( flow of traffic)

 

The rain slowed down a bit so i took an umbrella outside to look at the truck. The screw pictured here appears to only control how far the throttle cable can be pulled, so I don't think It will affect my truck. I have plenty of more "throw" in my throttle, its just that pushing the throttle down farther doesnt actually produce any more power, just more noise. ( only in fifth gear) I seem to gain power with more throttle until the rev limiter in every other gear.

To clarify, this screw ( the stop with the anti-tampering device) is not the same thing as the high idle screw that was mentioned earlier, is it? I was hoping the high idle screw adjustment might give me someresults.

 

The screw pictured is the high RPM adjustment. ASSUMING you are getting full travel of the throttle lever backing the high speed screw out WILL increase RPM at full throttle.

Sounds like you may need to adjust the throttle a bit to get full travel.

 

yeah you probably don't have full throttle, i need 1/16 more my self, i have to adjust it after i get a return spring for the pedal.