It doesn't idle bad. Slowly take the rpms up to 1,500 and the engine shakes very bad, you can feel it in the seat, and you hear a miss when you listen to the stacks. Once in a while the truck won't start it will just crank and crank and doesn't start, no service engine light or smoke out the stacks. Let off cranking, turn the key to off, then turn the key to start, and it will start every time. Whats my problem?

 

Hmmm... The only thing that I can think of is a bad injector, although the idle would be funny. Maybe a UVCH starting to come loose? If you have nothing else to do, take the valve covers off and check the oil discharge from each injector both at idle and at 1500rpm. Does it make a woofing noise at idle? Maybe a valve problem. If you can check the pushrods to see if they are all straight that might be another point. As far as the cranking, maybe the computer isn't seeing the minimum pressure to start and won't fire the injectors. Is your HPOP full when this happens?

 

All the injectors are new, maybe 1,300 miles on them. No not really any woofing noise at idle. Pushrods are fine, HPOP is full.

 

X2....This would be worthwhile.If neither is loose you can get the .50 cent mod done while you are in there if you haven't already

 

When the truck is running, and I unplug the icp the truck runs the same, doesn't sound any different at all. Is that normal?

 

I thought it was supposed to smooth it out if something was wrong with it.I get confused when reading so much about all this stuff.
Others with more knowledge will chime in though.

 

From the tech manual for "Runs rough- Acceleration"

Perform the following preliminary checks:
Confirm brakes are not dragging.
Confirm transmission and axle fluid levels.
Confirm transmission and axle tube are not "cooked".
Check for oil in coolant.
Check engine oil level.
Confirm oil change within 8,046.5 km (5,000 miles).
Check air intake system: Air Filter Minder.
Check MAP sensor hose for holes, blockage, or disconnection.
Check intake manifold system for leaks.
Confirm acceptable SAE oil viscosity and API rating of oil.
Check for sufficient clean fuel.
Check for intake restriction.
Compare loaded weight of vehicle with performance expectations.

Perform KOEO On-Demand Self Test- get trouble codes
Perform KOEO Injector Electrical Self Test- buzz test

Check For Biased ICP Sensor

Check Fuel Pump Pressure

Check Fuel Regulator INSTALL a new regulator valve if there is evidence of sticking or foreign material.

Check Pump Inlet Restriction

Check For Aerated Oil

PERFORM Injection Control Pressure Test

Check For Low IDM Power

Check Lubrication Pressure

PERFORM KOER On-Demand Self Test

MONITOR ICP while cranking

RECORD IPR at specified rpm.

Check For Biased EBP Sensor

Check For Exhaust Restriction

PERFORM Crankcase Pressure Test

Check For Piston Or Valve Leaks

Check Fuel Injector Oil Discharge REMOVE valve covers. OBSERVE oil flow out of fuel injector spill spouts with engine at idle. If there is high oil flow, INSTALL new fuel injectors.

Check For Biased EOT Sensor

Check Charge Air Cooler for Restrictions

CHECK operation of: intake air temperature (IAT) sensor, manifold air
temperature (MAT) sensor, engine oil temperature (EOT) sensor.

WOOOOOO!

 

I might be crazy but what about the CPS?

 

replace it with the gray one, idle and sounds much better, but still shaking at 1200-1800 rpms

 

hows the blow by look if you pull the oil fill cap off while engine is running?

does it shake above 1800 RPM? does it have the shakes in park or only when driving?

 

blow by is normal, yes it shakes above 1800, but not as bad. doesn't seem to do it as much if i'm driving

 

sounds like you really need to get a scanner on it and do a CCT.

Is this truck an auto or 6 speed?

 

auto, 91k on the truck. Just ordered a scan gauge, once that gets here I can give you guys some numbers to work with

 

will the scan gauge perform diagnostic tests (CCT?) or just give you DTC's and current parameters?

 

Not sure, if it doesn't I know my buddy has one that will. I just always wanted a scan gauge, thought this would be a good time to get one.


talked to a guy at swamps about this problem, and they said it very weird. If it was a sensor or something like that the check engine light would be on. Like I said before injectors have 1,300 miles on them, always clean fuel and oil. Tried a different chip, same problem. Anyone think its something in the motor?