swapping 181's for SDX comp 7mm DV's = Headache

Kronic_187

Kronic_187

Mekanical injection junky
Joined
Sep 27, 2009
Messages
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swapped out the 181's in my buddies truck for my set of SDX 7mm comp cuts. His truck now has a choppy idle below 1000 rpm and when is neutral will take off to 2000rpm and hang there.

it's n a 98 12v auto, 215 pumped truck that has racked barrels and .120 lines.

with the 181's it did lope a bit when it was cold but nothing major, and it went away after a few minutes of run time.

Now it's got "rail hang" like a smartied CR in neutral and in gear... and it's never consistent... sometimes it'l hang @ 1200rpm and up to about 2000, other times it'l come right back down. it never takes off any higher then 2000 rpm though... or tries to run away.

we tried taking a click out of the gov springs, which mellowed out the rpm jump quite a bit... but its still happening.

ive heard of stuff like this while trying to set up a GSK.... not from swapping DV's.... any help would be sweet
 
who turned the barrels? how many clicks are on what springs?

all i had to do was turn my idle up. my truck was all stock at that point.
 
I have yet to see a delivery valve swap cause a rack hanging issue, are you sure all the valves/seats are installed appropriately? It could possibly be something binding with the compression spring/holder, but again I have never seen the symptoms you describe. I will be out of the Country for the next week, but feel free to message me and I will do my best to help.
 
when i put'm n my truck, all i had to do was raise the idle.
They ran, idled and drove perfectly in my truck... I pulled them due to them fueling too hard for the hwy etc. with my setup.

Friends truck used to be owned by Calgary Diesel Performance and is supposed to have 5k springs. CDP did the pump work. I've never dealt with setting up a set of 5k's, but awhile ago he said they free-rev'd it to over 4k so im assuming it's got 5k's in it.

when taking a click out of the gov springs we noticed that they only seemed to give 2 clicks then got tight.. we couldn't go any tighter, so we set them @ 1 click per side and fired it, nothing changed other then it didnt jump to 2000rpm and stay there anymore... it hung a bit then slowly came down to about 1200 then dropped down to 750 like normal.

Im not trying to point figures as they ran fine n my truck... i just want to help him getm dialed in.
 
I understand, but I have never seen a delivery valve change cause your symptoms, nor can I think of a reaon that it would if everything went properly. I would go through the process again making sure everything is installed correctly, if it checks out I would suggest looking into the governor as the cause.
 
My truck would lope when it was cold with two clicks on a set of 4k so I put two more clicks and it wouldn't start w out throttle and brought my idle from 850 to 1100 and it would die going into gear. No hang ups though
 
Maybe when you torqued down the delivery valve holder, it put weird pressure on one barrel and somehow distorted it enough to cause a plunger to slightly hang.

Try loosening the DV holders and following the proper torque sequence of: Pre-torque the holder to 40 NM (29 lb. ft.). Next, in one motion, torque the holder to 115 NM (85 LB. FT.)
 
Yea DV wont cause that issue unless there was already an issue there and these DV magnified the issue. Sounds like a gov issue. Who's gov springs?
 
I had a set of 5ks that did that. No matter what they were set at they would hang at 2k or they would barely idle. Swapped them for a set of CDS 5k and was good to go. I have some videos of it somewhere.

Garrett

probably getting paid at work to post this from my bionic
 
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