7.3 help???

[Bent Bolt]

Does it shake alot and sound like a lopey idle ?? What happens when you floor the accelerator pedal in neutral ??

 

[bigblak250]

Does it shake alot and sound like a lopey idle ?? What happens when you floor the accelerator pedal in neutral ??

yeah, kinda, shakes really bad at low rpms when im takin off, when u mash on it in neutral it smoke really bad

 

[Roadkill]

Won't be a UVC (Under Valve Cover) harness if it smokes AND is rough. If one of the connections goes then that injector CANNOT cycle at all. These are hydraulic/electronic injectors. I had 3 connections go on one side of my PSD. Shook like an earthquake but DID NOT smoke.

Since you are FL, your EBP valve most likely won't be on most of the time. It could have cycled and stuck closed since it is never used. The soot buildup could cause that.

Like it was said you are warm enough that the glow plugs probably don't come on much if at all most times.

Has ANYONE checked the CPS (Crank Position Sensor)? There is a recall on them for our engines right now. You can get a cheap replacement from an International Truck Parts counter. International makes our engines and the parts from them are A LOT cheaper and also are the proper updated versions.

 

[bigblak250]

Won't be a UVC (Under Valve Cover) harness if it smokes AND is rough. If one of the connections goes then that injector CANNOT cycle at all. These are hydraulic/electronic injectors. I had 3 connections go on one side of my PSD. Shook like an earthquake but DID NOT smoke.

Since you are FL, your EBP valve most likely won't be on most of the time. It could have cycled and stuck closed since it is never used. The soot buildup could cause that.

Like it was said you are warm enough that the glow plugs probably don't come on much if at all most times.

Has ANYONE checked the CPS (Crank Position Sensor)? There is a recall on them for our engines right now. You can get a cheap replacement from an International Truck Parts counter. International makes our engines and the parts from them are A LOT cheaper and also are the proper updated versions.

the cps will cause this? where is it located on the motor?

 

[ItsA5Spd]

sounds like the CPS. could be the problem, but may be injectors as well. The CPS is on the passenger side of the block beside the crankshaft pulley. When lookin at it, it has a 10mm bolt. Take the blot out and lightly pry with a screwdriver and it should pop out. As for forums, check out http://www.superdutydiesel.com/. Great site!

 

[Roadkill]

The CPS is pretty easy to take out and put a new one in. It is a cheap way to check things since on our PS 7.3's those little $20 parts can cause a whole load of issues. That unit determines when to tell the solenoids on the injectors to fire allowing fuel to be injected. If it is off, It will run rough as well as smoke since fuel is injected at the wrong point.

A bad injector could still be another issue but that is an expensive repair. The electro/hydraulic injectors in our trucks are very pricey. They tend not to fail too often though but are costly when they do.

Unless you have the software to run diagnostics and buzz tests on the injectors I'd start with a new CPS from International. Just go in to the parts counter at an International truck dealer and tell them you need a crank position sensor for a Navistar 7.3l turbo. If they ask for cubic inches it's 444.

 

[Bent Bolt]

The Crank position sensor ( CKP ) and Cam position sensor ( CMP )will cause stalling and/or no starts. Won't cause smoking.

Sounds like bad O-rings on the injectors or the injectors themselves. Especially if you mash the throttle in neutral and the engine smokes and farts at about 2000 to 3000 rpms and then revs to redline.

 

[Roadkill]

3000 rpm on a PS diesel is pretty much 500 rpm short of redline.

My CPS was bad and caused loads of issues, INCLUDING excessive smoke with no codes what so ever.

 

[bobbywalter]

cps can cause smoke. generally they just fail though.

a bad connection thru the gasket connectors can cause issues as well if its intermittent.


unless the idm is starting to lay down. orings are a possibilty for sure.


how does it run when plugged in overnight or a few hours before first start? did you try that yet?

did you check all the plugs?

 

[DieselTech07]

http://www.thedieselstop.com/

 

[bigblak250]

now its makin a loud ticking/tapping noise