Miss, same as many but not resolved

L

Livnbreathdsl

New member
Joined
Aug 15, 2012
Messages
41
I'll start off by listing the truck first:
1998 R2500 4X4 12 Valve
215 injectors from lee at contagious
Racked the barrels
Timing at 16.5*
Head gasket with studs done 5k ago
Boost elbow on stock hx 35
Guages(trans temp,egt and boost)
S&B intake
4" straight pipe
Amateur "tuned" afc
Trans just rebuilt

My problem is a low rpm miss, I have searched and searched and have found a few people with the same issue but noone ever posted a fix that I can find. It's there at idle, and most noticeable at 12-1400 rpm and seems to either disappear or be hidden at higher than 1500. I can't pinpoint it to a certain cylinder by cracking lines. Its not a completely dead cylinder. it's worse hot.

It's really bothering me when at idle and I think it's causing a vibration when locked up in OD and cruising. I am limiting driving it due to this. I need to get it figured out and I don't want to end up taking out my torque out because of the misfire.

Any input is appreciated, the racking the barrels and injectors did not change a thing except for a noticeable boost in power.
 
Thanks guys, I had thought about changing dv's but looking at pictures of them I didn't think they were really something that went bad. Guess I'll have to dig up the "how dv's work" thread and do some learning.

I racked the barrels myself. Been debating it for a while and it was a convenient time to do it when I swapped injectors last night. Egts never went up and all cylinder temps are within 5-10* of eachother.

I'll order up some dv's today, if they are local ill be able to have them overnight otherwise I'll call up Weston and get his 100cc he has posted up right now

Thanks again guys.
 
Well delivery valves should be in my hands late Saturday or so, I'll let you guys know how it pans out. Thanks again
 
Well got up this morning and worked on the old girl. its getting old so hopefully im done for a while now.

First thing I did this morning was swap out the delivery valves, didnt change a thing. So i moved on to double check my valve clearances and found a couple exhaust valves to tight, hoped this was the issue and carried on and started it and guess what! still there. so at this point im convinced its not fuel and has to be something mechanically wrong. pulled all my pushrods out, all straight as an arrow. checked my fuel pressure, was at 25 but i bumped it up to 30 just for good measure, still same old annoying miss.

I knew it was a balance issue somewhere, just wasnt sure where. I couldnt recall when the issue started, so I couldnt use that to solve anything. Finally i decided to do something to make the truck more fun to drive if its going to run like crap. So i dug out my new governer springs and went to work. Installed them and started the truck and BINGO miss is nearly gone! I couldnt believe it. I measured the pertrusion of the stud and it was at 0.040 on one side and 0.048 on the other and i didnt think much of it at the time. I installed and just went the usually 4 clicks and the studs were now 0.044 and 0.046.

there is still a very slight shake at idle which i dont think will ever disapear but now going off idle is 100 times smoother than ever.

So i guess the stock governer spring with only 200000 kilometers(125000 miles) worn and causing this? very odd imo but I am glad the mystery is solved and hope this helps others in the future from wasting time/money on nothing. Sorry if I dont make alot of sense. I am typing really quick right now and havent actually been on here on a computer for a long time.
 
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