wolf359

I just had the 3k spring on my 12v with intake/#8/4" exhaust done last night.

Everything works fine, idle adjustment was minimal, it was about 300rpm low when it was done. Idle adjustmet was made, and everthing was fine. Pulled very easily to 3000 plus.

The only thing I noticed that I didn't expect was an idle rebound when coming off the throttle.

As soon as I come off the throttle (at idle or while driving the truck), it drops and then immeditally catches at the bottom of the cycle.

Does this description make sense?

Anyone seen this before. I've not read about this on any of the other threads I could find.

TIA

Tim.

gunracer1

sounds like you need to tighten the springs a click or two.

Mcmopar

I was thinking about doing this on my Dad's truck, but he tows heavy and I heard that the 3K springs come on strong at low RPM's and then"die off" a bit and then come on again like gangbusters at the higher RPM's. Have any of the guys with the kit noticed that?

gunracer1

the 4k kit i put in mine made the throttle more tochy, as is i only drive with 1/4" of pedal now. but part of that was the the 370's, and part of it is the #100 style plate. but the 4k did make it more noticable.

MY WORLD

gunracer1,
How can you measure a click or two ? Can you illustrate or photo this movement to this novice? I have slow bottom end but big time top end. Can you measure the thread to top of nut or is this a trial & error method?
Please note the signature.
How much different is the 100 plate vs the tst #4 plate? Did you do the injectors & plate at the same time? I did a 350 hp & 1007 tq in june, not corrected for air & humidity. I'm on the right track, but some small adjustment will net some more.
How is the fuel mileage after these adjustments? I lost a couple of MPG, although I'm sure my heavy right foot has something to do with it.

wolf359

I went out and recorded it so you guys could see what I mean.

Listen to when I come off the throttle, there is a rebound or blip at the bottom of the idle before it settle's down again to a regular idle...


Idle rebound WAV file

98rammer

sounds exactly like mine did, i cured most of it by loosening my governor spring sets. i have a 370hp marine pump though, so wouldn't advise loosening them. tightening the springs and/or upping the idle will help that problem. when you tightent he governor springs, it'll raise the idle, and visa versa. so you'll need to adjust it to your liking after. one or two clicks tighter per spring pack should do it.

Tom

masonic-dodge

Mcmopar

Why don't you put a 4000GSK and valve springs in your dads truck that way if he ever wants to put an exhaust brake on his truck the valve springs will already be done. I've got the 4000s on my truck and I love them. I haven't got any problems with mine. Is his truck still stock? if not what has he done to it?

If you want to do the GSK + valve springs let me know, I've got all the tools to do it and we can bump the timing too. The good part is I only live a couple hours from you. I've got sundays free if you want to bring his truck down I'll help you and your dad out.

CRIS

dodgeman01

The problem as I see it is that the springs are too tight. I would back them off until the problem either goes away or you get to the end of the threading on the nuts. They say to measure and ut in just as far as the stock ones were but that only works for half the pumps. It took me a year of tuning my truck to get it at the sweet spot. It likes one spring a little tighter than the other which I heard not to do but it runs great that way and if I put them the same then I get the problem back again..
DM01

wolf359

So far one person has said too loose and one too tight. ??

Captain

I think mine did that 2 years ago when I put the springs in. it either dosent do it as much, has gone away completly or im just so used to it now I dont notice it.

Mcmopar

Masonic,

The truck is a 1996 4X4 3500 with the auto, I have added the AFE, 4" turbo back exhaust, guages, "mystery switch", turbo-master, #6 plate, afc spring kit, and a shift kit. The truck rocks, but when towing Dad has seen 1500*. This month I am gonna add a 14cm3 turbo housing to try to cool her down a bit. Some people have said change the plate, but Dad doesn't want to do that, he is very happy with the trucks performance. His boat on the trailer weighs about 17,000 lbs and you cannot slow this truck down even in the PA mountains. I have heard (but I don't know myself) that the 3K kit and the 4K kit make towing that heavy a problem?? Any comments?

Thanks,
MCMOPAR

dodgeman01

Actually two have said to loosen them up. call Piers he will tell you the same thing the two of us told you.
DM01

gunracer1

when i put in governer springs, if the idle is too high, they are to tight, too low they are loose. this is how i was told to set them up. you want them to have the same idle as you started with. mine has a slight romp when i let off the fuel when it is cool. once it warms up it goes away. i have not messed with them other than setting them up like i was told to do.
a # 100 plate comes on sooner than a #4, but a #4 has some serious rack travel on the top end. to keep the top end hp it would need to get as much rack travel as the deepest part of a #4.

dodgeman01

Thats works on a lot of pumps but Mine was a complete different anmial. It took a year and many calls to Piers to try to figure mine out. I put them in first the right way and never lost any rpms at idle. Thruck was so bad you could not drive it. Took them out to the last click and truck dove ok but was still a little bad. slowley clicked them in until there it was..... "the sweet spot"
DM01