Engine/Transmission (1994 - 1998) Idle issues with GOv Springs

[HOTRODDER]

Hi folks



Just installed a set of PDR 3k gov springs in a friends 160hp pump (94) and took her for a rip. As we approach 2500 to 2800 the engine seems to pulse and I see a faint hint of smoke out the pipe. THe Springs are what I would call tight ( set at 80 thou or so) but the truck starts and runs great and the longer we drove it the less this seemed to happen.

BUT... ... .

He took the truck for a drive home and gave her a shot up to 24-2500rpm and it started chattering ( as he described it) now with the truck in park it idles lopey ( up down etc) What went wrong? Are the springs to tight? I have heard some talk of only using 30 thou but I set them to the same spec as the ones that came out of the pump. (yes they are both set the same)



Any ideas?



Fuel pressure?



THanks

 

[Jim Fulmer]

You said it idles fine but did you have to adjust the idle setting and if so how much, I have yet to have any issue with Gov springs that was no self induced.



Jim

 

[Howard Durand]

80 thousandths seems pretty tight based on what mine were. (about 0. 040 and 0. 046 stock)

Yes, they were different but I installed them both at 0. 036 and they really made a difference in the way the truck runs.



I followed the instructions posted by Relentless Diesel Performance.

Found here, http://www.flex.net/~triplem/new/govspring.htm



They are well written and provide good information.

A good supplement to what you get from Piers.

 

[Jim Fulmer]

How about inital click plus 2 and try that (check idle from before springs) if it needs one more click then do it... . some do but not all.



Jim

 

[RHARVEY]

Did you measure the distance that the stud stuck thru the nut before you took it apart???? Every set of springs that I have done. . I measure first then I set the new springs up with the same measurement. Also I have always had to reset the idle up some. I do believe that anywhere from 40-52k is about right...



Rick

 

[JGheen]

I agree with RHARVEY,



I measured mine before install and after. I ended up with about . 040" on one and . 055" on the other and ended up having to back off on the tighter nut and it ran a lot better. Just idled kinda high before I backed the nut of one click. According to the professionals, one click is worth about . 015"-. 017".

 

[JohnE]

A 160 hp pump. These need the 2 click adjustment and sometimes 4k springs work better.



I'm thinking you need the timing upped to around 15° to get rid of the problems at 2,500 rpm.

 

[JBlackwell]

I got the 4K installed last night and before I pulled the nut off both sides of the governor springs were . 012, so that is how the new springs are now. Are those too loose?



JD

 

[HOTRODDER]

hi folks,



Thanks for the replys, I did measure the springsbefore and I set them a little looser than the stock ones ( dealer pump repair so it was kind of hard to start)



Set them down to the 0. 036 or there abouts ( close as i could get them was 0. 041 and it worked great at an idle and no poping near the top, But the problem I have now is its got no go in the mid range ( I am going to try 0. 055 or a little higher to hold the lever down in the mid range of the cam plate for a bit longer) beacause this thing is now a dog,

Max boost in current setup ( PDR HX40, 215 injectors, #4, and 3K ) is 17 psi and no more than 1000 on the egt's! By the way the intercooler and all connections are fine ( I pressure tested them to 45 psi and no leaks)



any ideas



THanks

 

[JohnE]

I wouldn't mess with the governor spring setting.



You hit the current problem; plate profile versus governor lever position.

Try adjusting the governor lever and see if you get some midrange back.

The better option is a plate profile that compliments governor springs.



Timing?

 

[blacksheepdiesel]

rampuller,



Installed 4kGSK in my friend's '95 with 160 pump, works GREAT!



Are you still getting the pulsing? Two thoughts;

1. Check fuel filter and strainer for blockage.

2. Could be beginning to defuel. Just because they are 3kGSK does not mean it will rev that high, rather that it raises the point at which defueling begins. The 4kGSK in this '95 will not rev to 4000 rpm but it did substantially raise the rpm before defueling begins. This truck also got 370's at the same time and already had a #8 plate and 13. 5* timing. Yesterday I bumped the timing to 16*, have yet to test it.



Trent

 

[HOTRODDER]

Hi folks



Timming is at 15. 5 and I am sure this thing is not defueling ( it just doesn't have the get up and go it did when the springs where tighter, Its got lots of fuel comming in ( and it does reach about 2800 rpm under load) it just doesn't have the same kick in the pants it had before i loosened the springs, Maybe I will do the valve springs and add the extra sping for the 4 k kit.



Thanks

 

[DBCooper]

rampuller, have you checked the gov. arm to plate? Mine did the same thing yours is and that was the problem. It made a huge difference.

 

[HOTRODDER]

HI there



I will take a look at that arm and see what its doing, But its not like the thing suddenly turns on at any rpm ( level jumping by the nose) it just doesn't want to go, Like I said, All I did was loosen the springs and my boost went from 30psi to 17 with a heat drop of 1350 to 1000 degrees, I did nothing else, The plate has been in the same position all along and worked great before we started with the springs. I'll give it a try and lwt you know.