Engine/Transmission (1994 - 1998) How do the governor springs control idle.

[RonA]

I installed a new pump on my truck last week. I believe it has a gsk in it set for about 3500 rpm. I have tried loosening and tightening the governor springs and i cannot get it to idle at less than about 1200 rpm. Even when I set the idle at 1200 or so, if I turn the engine off and restart, I have to push the throttle in a bit to start it. If I do not it will start and immediately die. Once I get it started and it runs for a couple of seconds it will idle. If I back off the idle adjustment till the rpm goes below 1200 or so it will stumble and die. I was told to drop down to a 3k spring kit. I will install one next week. What is the difference as far as the idle goes. I understand more spring tension will keep centrifugal force from defueling. But what is the relationship between governor springs and idle?

Ron

 

[HoleshotHolset]

The largest spring in each one of the 'packs' is the idle spring. When swapping out governor springs, that is the only spring that you reuse. With that in mind, you shouldn't see any difference between a 3k or higher rated GSK as far as the idle is concerned. After it's all said and done... a normal GSK swap shouldn't affect the idle at all. If your idle is too high, the springs are too tight...



How do you have the spring packs adjusted? I've had very good luck with this extremely simple method:

1 soft click and 2 good clicks. The first click is barely noticeable... the 2 good clicks are what you're used to feeling when adjusting.



It sounds like you have to do a combination of governor spring and idle adjustments... which is frustrating to say the least.



Matt

 

[RonA]

Tightening and loosening the governor springs changes the idle rpm. But it has no effect on being able to set the idle speed below 1200 rpm. If i back off the idle adjustment and go below about 1100-1200 rpm it dies. Tightening or loosening the springs does not change the rpm that it dies at. If the pump timing is advanced too far will that effect the ability to adjust the idle down below 1200 rpm?

 

[HoleshotHolset]

I don't think pump timing is the problem... I'm almost starting to think there's a problem in the governor section of the pump. Out of curiosity, where is your timing set?



Are you using an OEM shutdown solenoid? Have you tried running without it? The default position of the shutdown lever is the 'run' position... so, they'll run just fine with the solenoid out of the truck... just push the lever down to shut it down. Disconnect the electrical connector, remove two bolts and a cotter pin and you'll have the solenoid in your hand.



Matt

 

[RonA]

I am running the OEM solenoid. Timing is a mystery. The pin timing was set improperly and the pump has a different cam in it. It was supposed to be set at 19 deg. They think it was set at 38 deg. Didn't run too good there. I reset the timing to a point 1/2 way back which should have put it at 19 deg. I measured plunger lift, and it was at 7. 0. On my 913 19 degs was 6. 2mm. I decided to try it at 6. 6 which should be less than 19 deg with this pump. Oh well, I sent my 913 in to be rebuilt. I should have it back in about a week or so. If I can't get this one running by then I put the rebuilt stock one back in. I have heard that it is normal to take 2 or 3 trys to get one done properly.

Thanks for the info.

Ron

 

[HoleshotHolset]

Crikey... I didn't realize how many pump swaps you've been through on this thing. I sure hope the rebuilt 913 runs OK... that's your safest bet at this point.



Who's doing the pump work? Making multiple attempts at getting one to run right doesn't sound normal for something with a 12-valve head. Your situation is a bit different with a 24-valve head...



Enterprise Engine has some sort of trick to make P7100's run very well on 24-valve headed engines. Finding the right injector pop pressure is 1/2 the battle... the rest is sorta mysterious.



Matt

 

[RonA]

This is only my second pump. When the 913 comes back I think it will be ok. 3rd time is supposed to be the charm.

 

[HoleshotHolset]

Ron: I'm glad you're a patient man. This type of work would drive some people nuts... myself included to some extent.



Matt

 

[mikel]

I took a gamble on a used pump one time that did this exact thing, it turned out to be something bent/broken in the governor. It just wouldn't idle below about 1300 rpm. Sorry to say, but from what you describe it sounds like you have the same problems that I ran into. I too had to do the "pump swap shuffle", and it ain't fun. I feel your pain...



Mike

 

[RonA]

Pump number 2 idles now. Quite well actually. Doesn't buck accelerating out of slow corners either. Installed a different set of springs, I believe 3k kit. Ran the retaining nuts down to flush plus 3 clicks. Won't start without a little throttle and won't take off in first without a little throttle. Don't know why, but was told that was expected with this pump. Didn't learn why, but the springs made a big difference. Now I get to figure out why it is low on power. I'm thrilled

 

[HoleshotHolset]

Dang Ron...

I sure am glad you don't take these frustrations out on projects at the machine shop!



Matt

 

[RonA]

Matt.

Thank you for the check. My truck is going up to PDR on sunday for a look see. I decided that was my next to the last option. I have tried to talk to it with no luck . So I decided on a more firm approach. I'll have a picture in my readers rigs today called "no more screwing around". Just another shop project.

Ron

 

[HoleshotHolset]

Thanks again for your help, Ron.

I sure hope you get that thing straightened out.



Matt