PSYCHOFAB

I have about 170,000 miles. no tuners or boxes. the truck will rev up to about 2500 rpm between *****. If i leave the clutch in it will rev up and come down like I raped the throdle. what could cause this? maybe injectors?

cbrahs

sounds like a leaky injector.



off topic- what part of cali are you in? I will be in San Diego area next week.

PSYCHOFAB

High desert Lucerne Valley.

Also My truck wont start if its below 50*F. not sure if its related or my heat grids broken.

Do you think I need new injectors or just new tips? there still the originals.

Hummin Cummins

Do you have the recent PCM/ECM flash?
...there is a 'low power' flash available and in that is a fix for a #6 (and #4) injector phasing (lean condition?) as well as remodulating the throttle pedal (although not advertised in the DC flash description section); my rig had a 'fluttering' idle as well which seemed like an out of phase injector pulse.

My rig had a floating idle around the same mileage; the flash fixed it (after I was at 3-garages trying to get it fixed, one tech noticed the new flash and asked if I wanted to try it, I said "why not"). Whether the floating idle is milage related or not OR that it will fix yours...I dont know.

Ron

RTillery

Sounds similar to mine. It would hang the idle up at 1000-1100 rpm and began to have starting problems as the weather cooled down. New set of injectors fixed everything. I would try something fairly simple first though. Check the torque on the nuts that hold the crossover tubes to the injectors in place. Good luck and let us know what fixes it!

Hummin Cummins

I would check the cross over tubes for leaks ("dont" try to tighten as sometimes they break, and I'm guessing you dont want to be part of the 'sometimes' group) and check into getting the PCM/ECM flash updated (if it's not already).

Injectors are expensive.
When replacing injectors, it's best to replace the tips, and also best to replace the set for consistency in fuel delivery and quality of drivability (what I did).

Hummin Cummins

A new set of injectors didnt fix mine as I thought it was an injector issue that stayed behind after the new injectors were installed.
However the flash did.

Was your rig ECM/PCM re-flashed at the same time injectors were installed (if not definitely check as I hear from other Private Messages about the misfiring #6 causing 'major' engine damage to #6 piston and cylinder when hauling....and not that this is positive 'proof' information, just a thought from others experiences I figure I would pass along)?

BR1

I was having something similar to that happening also. ran some seafoam through the filter housing, and starting running 2 cycle more consistantly, and have not had a problem in 20K miles

Hummin Cummins

Shouldnt have to add any elixors or make majic potions to run the engine properly.

Check to see if you have the flash.

bemhoff

Hummin Cummins what flash are you talking about. I have an 03 with only 35k miles on it. got it in Janruary and I noticed mine will almost stall between shifts. If I accellerate, let off the throttle quick and hold the clutch in it will almost stall. It actually has dropped as low as 400 RPM. To the best of my knowlege the ECM has never had any flash updates.