West said:
If the cam position sensor is acting up, you should see if the tach moves while cranking. Do you have a spare CPS to swap in and test?
I have a spare that’s good, but the current one was recently replaced. I’m really down to only the HPOP and main wiring harness as the only original parts.
@Noor
I’ve had similar issues due to a partially disconnected under-valve cover harness or even a bad accelerator pedal. When the harness disconnects, the engine can misfire; a failing pedal can cause it to idle only.
West said:
If the cam position sensor is acting up, you should see if the tach moves while cranking. Do you have a spare CPS to swap in and test?
That advice doesn’t apply to 2002/2003 models of the 7.3.
I had a similar issue on my old 6.0. Turned out to be a small break in the ICP wire about a foot down. It took ages to find!
Following… Same issue on my 2002 7.3. Replaced the pedal and IPR but still happens when it’s warm.
Could be a bad ICP or wiring. Also, low oil levels can cause rough idle on a 7.3. Glow plug or injector harness might be worn out too.
Bryce said:
Could be a bad ICP or wiring. Also, low oil levels can cause rough idle on a 7.3. Glow plug or injector harness might be worn out too.
It also sounds like an injector issue. I replaced mine recently My rough idle fixed
@Bryce
That’s all new for me.
Check your cam or crank sensor, especially if it’s covered in oil. Also, any valve cover gasket issues?
Ridley said:
Check your cam or crank sensor, especially if it’s covered in oil. Also, any valve cover gasket issues?
Everything is clean, including the valve cover gaskets. All replaced recently.
@Noor
If you’re sure about that, it could be the HPOP. It’s not common, but stiction could also be an issue.
Ridley said:
@Noor
If you’re sure about that, it could be the HPOP. It’s not common, but stiction could also be an issue.
Just took it out and pushed it hard. Holding at 2800 PSI on the ICP at full throttle.
@Noor
Did you check fuel pressure at idle and while driving? Might want to try some stiction additives if you suspect that.
I have the same issue. Replaced sensors and oil, but I get idle surges sometimes. Could it be stiction?
Keaton said:
I have the same issue. Replaced sensors and oil, but I get idle surges sometimes. Could it be stiction?
Doubt it. Everything on mine is practically new.
Maybe a slight boost leak from a CAC hose?
Steele said:
Maybe a slight boost leak from a CAC hose?
No boost at idle, so that shouldn’t affect anything.
Had this issue after installing new injectors. Turned out one injector had a minor flaw causing idle issues.
Fraser said:
Had this issue after installing new injectors. Turned out one injector had a minor flaw causing idle issues.
Just replaced my injectors too. Hope that’s not the case.
Sounds like a fuel delivery issue. Try checking your fuel pressure—it should be around 60 psi at idle.