shutter???

[redseal119]

so here is the deal 6.0 with a shutter at 50 to 60 mph in overdrive with rpm's at 1500. it does not do it in any other gear at any other time. I have balloon tested and buzz tested both showed no problems with injectors could this be a trans issue?? if so how should i test the trans?? if not how do I figure out which injector it could be. also give me some feed back on this rev-x stuff?? thanks

[MarkBart]

on some modded trucks the automatic tranny cant keep up witht the demands so ( on a friends cummins this happened) it would shudder goin into lock up at specific rpm and speed. to try and solve it he had a local technician crank up the line pressure (adjusted in the tranny) and it solved the issue

[redseal119]

the only mod I have is a delete kit with up pipe. everythis else is stock ???

[ClaytonG]

I have also had this problem in my '03 6.0l Overdrive only, but it will do it from 1500 rpm to about 2100 rpm. I had a bad ficm and #8 injector and read somewhere on here that it could be caused by that. I put in Swamps 58v hot ficm and though the trucks starts, and runs worlds better i still have this issue. I did change the #8 injector with a used from ebay and it just did it worse. All new injectors are going in. I will post if it makes it any better

[redseal119]

let me know how it turns out for sure!!!!! also I had a contribution test and buzz test ran on my truck. it passed the buzz test but cyl 4 had no contribution so I pulled the glow plug and seemed to have good compression??? I ordered a new injector for this cyl today and will let you know what happens... fyi I also tested the ficm it was ok..

[rdodger]

i also have the same shutter just for a sec if i am @ 60 -65 . one of the guys above said it can be line pressure . i was wondering if i could up the prssure on my sct , would that work ?

[Deagle44]

I have the same issue, My injectors test out fine as far as a scanner is concerned, but I know I have a miss. I can sit in park or neutral and rev the truck up to 1500-2100 and you can watch the RPM bounce a little and feel the truck shake a tad. Just going to put a whole new set of injectors in. Replaced FICM not to long ago and it is fine. I think it is just a sticky spool valve on one of the injectors, sounds like you may have the same issue.

[ClaytonG]

I was also thinking the sticky spool valve at first so I switched from 15w40 rotella to 10w30 rotella (with rev-x) then to 5w40 t-6. IMO the rev-x did nothing but lighten my wallet. The used injector i bought was worse than what i had in to begin with. I am not a transmission guy so I can't comment on line pressure or anything (my cousin does all my trans work for me). But I have read posts on the .org and nation before about this and nobody ever seems to get it figured out. Maybe one of the techs could chime in?

[redseal119]

ok mine is fixed!!!! so here is the deal I ran a contribution test and found a cyl that was not contributing. I then checked compression and it was ok so???? prepared for a injector took valve cover off and oh boy bent pushrod!!!!! also with closer inspection I found a cracked rocker arm so I replaced and everything seems to be good now!! so if you get the valve cover off look real close at push rods and rockers as I had this problem on the other side also.... thanks for everyones help

[Deagle44]

glad to hear you got it fixed but now you have me worried!!! haha. how do you run a contribution test?