Engine/Transmission (1994 - 1998) 3k gsk / afc spring - no mid power

[guldam]

I installed a set of 3k GSK springs yesterday, and while I was at it, I installed, an AFC spring. Everything went back together easily and painlessly. GSK stud to nut clearance is . 045" on each side.



Starwheel all the way forward.



Truck starts easily but idles at 900-1050rpms. My idle adjustment bolt is already bottomed out, so I suppose I'm going to have to change the length of the throttle rod.



The thing that has me confused is that at low/light throttle the truck moves forward effortlessly, but as I keep pushing the go pedal down the truck just kind of sits. No middle rpm power. It will rev to 3k and beyond whereas it never wanted to do that before. So I'm losing the big torque jump at 1700 rpms. Is this characteristic of the 3k GSK ?



Thanks,



GulDam

 

[guldam]

I guess I'll just answer my own question.

Found on another site that has a bit more traffic these days:

Some people will have problems after installing a GSK. 95% of problems can be tracked down to installer error. Common errors that we get phone calls about are :

Taking the large spring out of the pump and removing idle shims. This will mix up the pumps ability to idle correctly and lower total fueling rpm's. Instructions say to remove stock bases and any shims on each side of the gov. without removing the largest spring. At no time should you take the largest stock spring out for any reason. Instructions clearly say "Do not take out largest spring", but 50% of the calls I deal with, customers do just that. [duhhh]

Another common error is not putting the AFC back in the original spot or moving it back towards the fire wall, which will hurt bottom end. If anything, the installer should push the AFC full forward (towards the front of the pump) and adjust star wheel accordingly.

Another is the installer doesn't take stock measurement before install. Measure from top of stud to top of the retainer nut and do so at the same position, whether that is at 3 o'clock or what have you for both sides of gov. Lower hp pumps tend to need more distance between stud and nut, in some cases . 080" but most are set at approx . 050". Each click is approx . 017"
If someone has been in to the pump prior to you, this could be a problem. Best to investigate to see what may or may not have been done. ( something missing, something added or just adjusted from stock).

Another is just poor measuring and one side gets more clicks than the other, which affects idle and the pumps ability to rev smoothly and freely.

The other 5% of problems are the need to adjust the gov. lever depending on the pump and plate. PDR likes the #10 plate, as it has the best overall profile and we haven't run into a pump needing a gov lever adjustment on a non molested pump.

 

[Missouri Mule]

Very good info.

Did you try doing a search on TDR, there should been quite a few threads.

 

[guldam]

P7100 tuning - TDR Roundtable

This is good:

3K GSK = soft pedal? - TDR Roundtable

I will pass on what Al with Piers said to me on the GSK. As a general rule he finds two clicks is about right or less rarely more. When you first start tightning you will reach a point that the "dogs" make contact and click each time you pass over one.

I had to loosen mine to try clear up a slight bounce at idle. I never checked how many clicks but when JohnE did mine we did not have to adjust the idle. When I loosen the retainer one click it dropped my idle. Becareful to drive the truck a little to decide on the idle. Mine idle faster the second I started it after loosening. After a short drive the idle settled down to about 600 (to low!).

I would guess if one has to lower the idle after install, the install is on the tight side (3 - 4 clicks), if one has to increase the idle one might be on the light side (1 to 2 clicks) but closer to perfect.

I still have a slight bouce (when letting the engine return to idle it drops slight lower the the idle setting and the quickly "bounces" up the correct setting) when the engine is cold.

Eric;
Lowered the idle?
Is the pedal slow to add fueling and then when you hit the sweet spot the fueling grabs and rpm jump quickly? Is that how you describe "soft"?
I had that throttle action (and despised it) when I reset my spring tension 2 clicks past snug. My idle also jumped to 1,100 or so. The flutter (idle bounce) also hit 1,700 rpm and I was trying to eliminate it by tightening the springs. I loosened the springs a click each and the flutter dropped to 1,100 PM, idle dropped to normal and throttle action is very even from idle to 2,200 rpm. The flutter only shows if I accelerate and then partial drop off throttle. It will flutter or bounce around 1,100 rpm, sometimes.

GSK is an art not simply an install. I use those words after talking with both Piers and Al at PDR.

 

[guldam]

The problem with any kind of modification and the associated advice is that very often the advice is contradictory. And then the kits you get, for example the 3k/4k GSK kits give the basic installation instructions but then fail to give information on fine tuning, and trouble shooting. A simple, "if your idle is higher than 50rpms over stock, then backing off on the spring tension one or two clicks might be indicated. "

The AFC spring kit I got was a "DDP" kit, that came with One Spring, no screws, and no installation instructions. Makes me wonder if it was actually a left over spring from a TST kit that the company had laying under the counter.

And so it goes. In the end I look at all the posts, decide which advice is good, and which is contradictory, and re-examine my installation. A 2hour install becomes another 2hours to tune or to double check myself, and another four hours of going back through postings on the subject. And I learn, sometimes the hard way.

And then when it's all over and things are working I try to come back and report my findings so the next person who runs into these issues has a more complete answer.

GulDam

 

[guldam]

Update, rechecked throttle linkage measurement I was off by 1/8" of an inch. It took two more adjustments before I got it exactly 5" from bracket to ball. I think there is perhaps a tiny bit lower idle.



Busy building a chicken coop so it will be next weekend before I get a chance to pull everything apart again and turn GSK out one click.



GulDam

 

[guldam]

PDR governor spring installation



3k today!!!!WOW!!!! - TDR Roundtable



https://www.turbodieselregister.com...n-1994-1998/35935-install-3k-gov-springs.html



https://www.turbodieselregister.com...-installed-there-own-geverner-spring-kit.html



need imediate help, GSK idle shim/washer question - Dodge Cummins Diesel Forum



I did not see these shims (that you are NOT supposed to take out. )

#ad




Good explanation of Washer Hack...

Gov. washer mod - TheDieselGarage.com



BD Instructions:

http://www.jegs.com/InstallationInstructions/100/151/151-1040185.pdf



PacBrake Instructions:

http://www.pacbrake.com/PDF/L5658.PDF



Stock Springs as they came out of one side. Large spring went back in.

 

[Mhannink]

welli would agree the idle is too high from the spring being too tight. back them off a click on both sides. as for the middle range power i might be wrong but afc spring full forward is more tension less fuel. i might have that backwards though. however make sure the housing is slide full forward. i know one indication your going the right way on the star wheel is it gets easier to turn as the spring load comes off so make sure that what you did. if that doesnt solve it then maybe you should get inside the pump and regrind the plate.

 

[guldam]

I'm getting closer.



Removed AFC Spring, and backed off the Governor Springs one click.



Idle is better, but still gets a bit high at 1k sometimes, low end torque is good. Mid torque at 1700-2000 rpms is quite a bit less than before. Truck will rev to 3k if I turn off overdrive, but it just isn't pulling like others have described.



AFC is full forward. #6 plate is perhaps 1/8" forward from stock. Starwheel is most of the way forward, or loosened.



I think all the fine tuning is an art.



GulDam

welli would agree the idle is too high from the spring being too tight. back them off a click on both sides. as for the middle range power i might be wrong but afc spring full forward is more tension less fuel. i might have that backwards though. however make sure the housing is slide full forward. i know one indication your going the right way on the star wheel is it gets easier to turn as the spring load comes off so make sure that what you did. if that doesnt solve it then maybe you should get inside the pump and regrind the plate.

 

[guldam]

Now this is interesting...

#6 plate not a good choice with a 180hp pump and 3k springs?

Hmmmmm... .

#4 plate? - TDR Roundtable

Same symptoms as mine, but they didn't post the Answer. DingDangDurnit. I hate that, which is why I keep on posting the info, and when I figure out the problem I will post the answer.

Reckon I need to check the lever adjustment.

PDR Diesel Inc. The turbo diesel performance specialists! - Lever Adj

GulDam

 

[Mhannink]

idk if the plate would be good or bad with the springs. they are doing different jobs but are related a little. i know there are some shims that are in the pump and if i remember they can easily fall out while doing the springs maybe you missing a shim.



something to consider is take it all apart and basically start over and just be more careful. not that you wherent before but ive done that before and it seems easier to start over and do it a second time

 

[guldam]

I was super careful taking the springs and shims out and putting the new ones in. Don't think I lost any shims. But I will go back in and back off the nut and re-measure everything. Some folks talk about screwing in the nut until the first soft click, and then tightening 1-2 tight clicks. I think that's pretty much where I am, but it won't hurt to triple check.



Interesting thing, one side was pretty loose when I first took it apart, and I think had all of one soft click, and the nut and stud were flush. I measured and remeasured a dozen times and came up flush each time.



More good stuff: The Governor





GulDam

idk if the plate would be good or bad with the springs. they are doing different jobs but are related a little. i know there are some shims that are in the pump and if i remember they can easily fall out while doing the springs maybe you missing a shim.



something to consider is take it all apart and basically start over and just be more careful. not that you wherent before but ive done that before and it seems easier to start over and do it a second time

 

[Mhannink]

maybe the other thing to do is if one was loose and one was tight set it the way it was before though they should be even. i dont like having the springs unbalanced its not suppose to work correctly that way.

 

[guldam]

Update

Haven't had much time to fiddle with the truck.

I was able to take five minutes to back off the starwheel yesterday about five complete revolutions, and much of my mid power is back. I did not realize that the starwheel could make such a difference.

Now that I think about it, when I installed the 3k springs I did move my torque plate forward a little bit, and also moved the starwheel forward. All these changes were too much, and as a result I have been getting too much fuel (I think). And "I think", I'm still getting too much fuel for the amount of boost I can make. The mid power is much better but not back to where it was prior to the 3k spring install. This is all about Tuning at this point, and learning that sometimes less is more, rather than just cranking everything up.

And so in hindsight, I should have only made one modification at a time, and to get that right before willy nilly adjusting everything. Will report back once I get everything sorted out.

I sure wish Joe Donnelly would write that book.

GulDam

 

[guldam]

I've been stupid busy at work and at home. But finally this afternoon I was able to take an hour to fiddle with the truck.

First I had in my mind that my lack of power was due to the AFC arm getting hung up. I wasn't making boost more than about 25psi, and what was the sweet spot at about 1700 rpms was doggish. Pyro never got beyond 1100 degrees. Sure seems like I'm not getting fuel, and thus no boost, no heat, no power... .

I had a #6 plate in, and I decided to take a #10 plate I had and to file it down to a #100. And so I did. It was easy, and here it is next to the #6 and the original Cummins plate.

Put the plate in, and moved it a bit to the front of the engine... Buttoned it back up together, and headed out for test drive.

SNORT!!!!

Hmmmm, what's that stuff behind the truck?

SNORRRRRRRT!!!!!.

whoa the truck is hauling butt... I'm getting on the freeway and there's a cloud following me, and I suddenly have boost climbing quickly... 20, 30, 35, whoa nelly !!! approaching 40psi, glance at the Pyro, and oh, oh beyond 1200, 1300... I took my foot off the gas a tiny bit and everything, including myself calms down.

Mechanical hang up of the AFC arm. Gotta be. That ski ramp of a fuel plate must have let the arm just do what it was supposed to do.

I've been babying the original transmission since it's stock and has almost 190k miles on it. But I can see this thing is history if I don't behave.

Gotta back off the plate a bit and get rid of that smoke. I don't want to be attracting any attention.

Life is mighty good.

GulDam

 

[CBlack]

Since I bought my new truck I haven't paid much attention to the 2nd Gen forums.

guldam,

I see you've been searching through other sites/forums for info.

Another site with TONS of info on 12V performance is Competition Diesel Forums.

They have a lot of stickies regarding plates, timing, injectors, etc. Information overload really.

 

[guldam]

I have been searching the web high and low to find the answers to my questions. Some sites have good, seemingly reliable information and others, well, not so much.



You have one group of overly cautious folks, and another group who push their trucks to the maximum with their mods. I'd like my truck to remain reliable, and long lived, and so I tend to fall into the middle. I want the mods, but I am going to strive to keep things reasonable, and avoid abusing the truck.



I must admit that I like my new found power, but I am also very cognizant of the fact that I'm going to break something sooner or later with the current level of mods.



Before I had my pedal to the metal to merge onto the freeway. This morning I'm having to feather the pedal to keep my EGT no more than about 1250 degrees. It gets there and beyond in no time at all. Of course the information I read on EGT is conflicting. Some say keep no higher than 1100, and others say 1350 is fine and others say an occasional burst of 1600 won't hurt anything. I'm leaning towards always trying to keep the EGT as low as possible. 1600 seems like grenade territory and 1100 sounds like my stock temps. On subjects such as this, I sure do like it when Joe Donnelly chimes in with his great experience and wisdom.



And so I carefully watch the gauges. And my gauges tell me I have to either move this plate back or go back to the #6, and keep it positioned in the middle, and of course keep the AFC arm from hanging up.



I'm careful to ease into the go pedal now, since I fear that big shift into overdrive at heavy throttle is going to shred my transmission.



And yep, I'm back to looking for a transmission. Tain't cheap when you are looking at transmissions designed for power and towing. But I've got the bug, and you gotta pay to play, as they say. Leaning toward Goerend , or perhaps having my local Diesel Experts, LeftCoastDiesel build me a transmission. They are also installers for Goerend. Just have to find the cash.



It's such a joy to drive this truck now. Now I know why folks put on Valet Switches, and why folks who drive these trucks seem to have a Schlitz Eating Grin on their mugs much of the time. You can't help but feel just a tiny bit happy when you have all that torque at your command.



I think I might have to do my happy dance.



Thanks for the link, I'll check out their postings (and likely get overwhelmed. ).



Life is good.



GulDam

Since I bought my new truck I haven't paid much attention to the 2nd Gen forums.



guldam,



I see you've been searching through other sites/forums for info.



Another site with TONS of info on 12V performance is Competition Diesel Forums.



They have a lot of stickies regarding plates, timing, injectors, etc. Information overload really.

 

[SSage]

Once you get a good trans it will be a new truck all over again. A tight TC that can actually handle the power is a life changing event. My DTT shifts smooth under full throttle and the dual tires fight for traction the whole time.



Then throw in some injectors and a bigger turbo and then the power becomes usable... Its so much fun blasting up a steep mountain at 35 to 40 psi at 2800 plus rpm passing sports cars... Good Times



I still like driving the old loud 12 valve more than the 3rd gen...

 

[guldam]

I'm working on getting a transmission. Talking to the good folks at LeftCoastDiesel on what I should be getting with the current power, and a bit more to come. They have a good reputation, and they are official installers for Goerend.



I can feel the transmission not liking the extra power. I will move the fuel plate back this weekend a bit, and calm the truck down. EGT's climb too high, and I have to be extra smooth or kiss that transmission byebye.



I love this truck. It's really amazing what a few bucks does to the Smile Factor of it.



GulDam

Once you get a good trans it will be a new truck all over again. A tight TC that can actually handle the power is a life changing event. My DTT shifts smooth under full throttle and the dual tires fight for traction the whole time.



Then throw in some injectors and a bigger turbo and then the power becomes usable... Its so much fun blasting up a steep mountain at 35 to 40 psi at 2800 plus rpm passing sports cars... Good Times



I still like driving the old loud 12 valve more than the 3rd gen...

 

[harrisonm3]

Stepped up from a #6 to a homemade #4 plate, and put a 3k spring kit in. Now it's like driving a new completely awesome truck.



I have great throttle response at any point in the RPM range. The truck used to bog down right around 50 mph and it took a while for the torque converter to lockup and for overdrive to kick in.



The spring kit was easy. The experience shared on here and the instructions really helped. I used needle nose pliers to tighten the spring retainer. My cheapo Harbor Freight caliper was all but useless. I more or less eyeballed the measurement and error'd on the side of two tight.



My idle was high but a quick adjustment took care of that. I wish I would have done the mod sooner.