Hi guys,
I installed a set of ITR cams in my GSR motor this weekend. The car barely starts and when it does the ignition timing is about 40 degrees advanced. When the car is at operating temperature the timing is 30 degrees advanced. The mechanical timing is all spot on as i have checked and rechecked that. With a jumper wire in the CEL plug under the dash, and the distributor at full retard I am still getting 30 degrees of timing. Nothing to my knowledge has changed with the car other than the cams and valvesprings. Any ideas?
Thanks in advance,
Micah

 

Did you check the valve lash adjustment after installing them?

 

I'm not sure that would affect the timing but yes, they are all in spec

 

Alright, I found the problem. Apparently, the pin holes in the ITR cams are not meant to line up with the holes in the GSR cam covers. Thus, the intake came was off by one tooth.

 

was just going to say this, you had to be a tooth off

 

It's probably easier to use the GSR gears on the ITR cams to line up as before...what intake and exhaust valve lash did you use with the ITR cams assuming you have a P72 head? You were lucky, a bit more off and you could have gotten bent valves.

 

gears are the same, both pr3

which is actually why i was wondering how the op was off unless he didn't tension the belt right and double check to the crank

 

I was a tooth off because I used the holes in the top of the cams to line up with the hole in the cam cover. According to this method, everything was correct. I also had Skunk two cam gears on the cams. While the cams were in the car and everything was set to TDC, I took the bolt out of the cam that holds the gear on. I matched the position of the keyway hole up to the keyway hole in my stock cam gear and it was a tooth advanced from what it SHOULD have been according to the stock gear. I loosened the timing belt, and mover the intake came back a tooth. The car started and ran perfect. This leads me to believe that the holes in the cam covers are in a different position in the ITR motor than the are in the GSR motors.

As for valve lash, I did .006" on the intake and .007" on the exhaust. (per Hayne's manual and other internet sources.)

 

Sometimes they look aligned and when you tighten things around they shift one tooth...

 

Maybe... but that is not what happened. After everything was tightened the holes in the cams still lined up with the holes in the cam covers.