well this morning i started up my truck and it had a wierd vibration to it at idle, it almost seemed as if it it had a slight miss to it...i reved it up to about 2200rpms to see if it would level out and it did after a minute or so but i was wondering if it has to do with the fuel/rail pressure guage i recently installed or is it somthing expensive like signs of a leaky injector,... i checked the blow by after it had finished shaking and there was nothing, i had washed the truck the night the night before and it was fairly cold out prob about oh i guess it would be around 33'F, but my old man thinks it was just from my truck being so cold which i hope it is somthing so simple

 

Mine is doing that during warm up,if I start the truck it idles fine ,when i drive to work the engine is getting a little warmed up after 5 -7 minets ,then if the traffic lights are red,I have a strange imbalance/vibration in the engine when idling ,just like it misses 1 cilinder ,if i rev it a little to 800-900 rpm its gone ,and after 5 minets more it is completely gone ....

sterling

 

mine sometimes does that too when i first start it up. Goes away by the time i get to the end of my street tho.

 

has it been doing this on your guys trucks for awhile because it just started doing this on mine and its kinda got me worried...also after installing the fuel/rail pressure guage i have seen a high of 12psi for fuel pressure..with my bullydog on extreme it can fall down to about 4, 5, or 6 what is safe for pressures to be runnig at i also think the highest rail pressure ive seen is 25

 

Sounds like everyone might have injector issues!

Not positive, but mine also developed a similar rough idle when the injector(s) went out. Is anyone seeing white smoke at startup?

 

I have just installed flux injectors 5000 miles ago,and it is doing this the last 2000 mile,when it also start to get colder here.
Mine had hard start issues before my flux injectors ,and according to Don (F1 injectors) I had 2 leaking injectors that were so bad he could barely test them,but when the engine was running it was perfect ,I mean I couldn,t tell the difference with the old injectors and the fluxes when idling.
I send the injectors to F1 only because I couldn,t start the engine anymore.

Anyway the vibrating ,could it be a damper issue ?

sterling

 

I have tried more pressure boxes on my '03 than I care to count...

One common thing I noticed, at least on my truck (and I've heard confirming reports from others) is that sometimes you get erratic performance/idle if there is not a good connection at the MAP and rail plugs.

Go to your local auto parts store and get some dielectric grease. Apply to the plugs and reinstall. You may be surprised. I was.

I carried a tube in my truck, as I swapped pressure boxes out depending on what I was doing. If my truck ever had a hiccup, my first thing to do was to reapply some grease.

 

no i havent seen any white smoke at start up and i have nothing coming out of my blow by , i really hope its not an injector issue, as i would think that an injector issue would be a constant vibration and not just when its cold

 

well ive been checkin for white smoke and i have been seeing a little bit hazing out but i keep trying to tell my self its because its fairly cool outside but im starting to think it may be an injector, my oil has not been rising though?

 

That's exactly how mine started off. It hazed all the time for a couple months. Then while towing a trailer on the highway for about 30min it got worse. When I exited the highway it started idling rough but still ran fine otherwise. A couple days later it poured out white smoke and had a REALLY rough idle when first started up. The rough idle would still clear up after a few minutes of revving and it drove fine afterwards. My oil level also never changed.