High Idle Problem

[Allmarine]

I have an issue with the idle on my 2013 F150 Raptor.
Symptoms:
Cold start idle is 1800rpm then after about 20 sec will drop to 1200rpm
In gear idle is about 800rpm
Deceleration sometimes the idle drops almost to stall then back to 800rpm
When hot after driving return to park and idle about 1200rpm then jumps to 1800rpm then slowly comes back to about 1200rpm
If you blip the throttle then it stays up momentarily before dropping back to about 1000rpm
The issue is not with the tune or parts as only recently occurred.
Engine:
6.6L Powerstorm, long tube headers, straight pipes, Roush supercharger, Cobra jet throttle body, 69mm pulley and JDM tune.
Diagnostics:
Technician has done a smoke test for vacuum leaks, none found though I do not know where he connected the smoke and whether it would have gotten past the blower rotors.
In gear, idle,
956 RPM
MAF 30.30 g/s
MAF 3021.00Hz
STFT 1 0.78%
STFT 2 -1.56%
O2 1 1.51%
O2 2 1.51%

Am I missing something here, I have ordered a new OEM MAF and PCV valve as they are cheap to replace. Going to do another more thorough smoke test though I have done the naughty and sprayed propane all around the intake manifold and valley of the engine and there was no change to the idle at all.

What else should I be looking at?

 

[Canuck714]

your in-gear idle seems high to me. My JDM SC tune was not quite that high on cold start or in gear.
I would call Jim at JDM to ask what it may be.
I cant remember which throttle-body it was that had surge issues, but that may be the issue.

 

[Allmarine]

your in-gear idle seems high to me. My JDM SC tune was not quite that high on cold start or in gear.
I would call Jim at JDM to ask what it may be.
I cant remember which throttle-body it was that had surge issues, but that may be the issue.

You are correct, the in gear idle should be about 725rpm. I recently fitted the 69mm pulley, JDM tune and Cobrajet throttle body however the problem was pre-existing. I have been emailing Jim for advise and he has been very helpful. I suspect I have a vacuum leak below the blower. I had a tech do a smoke test however I don't believe he got the smoke below the blower blades only above and out the intake. I am going to do a more thorough smoke test but cannot get use of the machine for a couple of weeks.
Removing the blower and resealing the gaskets is not that big of a deal, I was just opting for the easy checks first.
I had a timing cover oil leak which was repaired in Jan 22 which required the removal of the blower and some other bits for access. I suspect that the components may not have been sealed properly but I cannot recall noticing if the idle was high when I got the truck back or not.
It is likely I will just pull the blower off and seal all the gaskets anyway this weekend, I am hoping that is the issue otherwise it's going to be a lot harder to diagnose.

 

[Canuck714]

Ya probably a great place to start. Considering the blower was off to repair the cover it probably is an air leak.
Good luck, let us know what you find.

How many Raptors are in Straya??

 

[Allmarine]

So anyone interested in an update on this issue. The previous owner had installed a catch can to the passenger side of the engine (between the PCV valve and the blower) however he also T this into the vacuum line on the drivers side (between the rocker cover and intake tube) resulting in the boost pressure going into the intake between the MAF and the throttle body. Once I reconfigured the vacuum lines, problem solved.
Before all those experts start saying this should have been obviously visible, please remember this is Australia and steering is on the other side and a lot of vacuum lines and other components are reconfigured to fit into the engine bay because of the steering column being opposite. It doesn't look the same in a lot of respects.

 

[1BAD454SSv2]

Do you have any pics? like to see a right hand drive Raptor .

 

[Allmarine]

Do you have any pics? like to see a right hand drive Raptor .

 

[Irregular F150]

Thats sweet. I want one lol

 

[1BAD454SSv2]

Wow very cool , but that would screw me up driving on wrong side . LOL just kidding . Was it converted or built that way ? If converted looks very well done .

 

[Allmarine]

Wow very cool , but that would screw me up driving on wrong side . LOL just kidding . Was it converted or built that way ? If converted looks very well done .

These vehicles are converted here in Australia. Several companies do this however like everything some do a great job and some don't. This is one of the good ones.