MCX 260 Apex hard starting??

[MRFUSION]

I have a customers 06 Apex in my shop with a MCX 260 kit that was installed by the previous owner. He brought me this unit and I went right through it repairing all sorts of connections and small issues. The aux injectors were not firing and I had to replace the MCX plug at the control box. Unit runs great and pulls hard but wont start very well at all after being outside for awhile. It will turn over well then fire up for a few seconds then will only turn over and stutter but wont start. Drag it into the heated shop and you can feather the throttle and eventually you will get it going then it runs great. Stop running it for an hour or so and it starts hard again. I have the ground for the MCX box to the engine and all wiring seems ok. The only other thing I can think is a tooth off on the cam timing when the head shim was done. Seen that before. Any suggestions before I tear the into the top end to check the timing? Thanx for any help guys.
Cheers.
Shad

 

[rxrider]

Any AFR gauge?
What Reading do you get at idle when it runs?
Could be a valve shim out of position leaving one of the valves slightly open when Cold. A compression test would detect that.

 

[MRFUSION]

Thanx for the help. I tore into it and found who ever installed the system ground the exhaust instead of the intake cam sprocket. Corrected the timing and and she purrs like a kitten now.
Shad

 

[rxrider]

Makes Perfect sence, glad you found and fixed the problem