Timing issues

[John S]

I want to apologize up front because it seems like the only posts I make anymore are asking for help. There have been so many little issues popping up and I admit I am getting very frustrated but here goes with my latest problem.

Now that I had to replace the cam in my engine and I got it all bac together there seems to be another problem.
IF I run the engine easy it has been running ok, but if I get on it even slightly hard the engine jumps timing. I plan on tearing back into it tomorrow but i am unsure what direction to start with.
As far as I know there are three things that can move, the first two mechanical the last electronic:
1) the timing chain can jump, but wouldnt this cause the possibility of significant valve damage?
2) the distributor can move, It's locked down tight, but what would cause it to move?
3) Timing control in the ECU

The timing chain is a Cloyes double roller, the ECU is a FAST XFI unit and the distributor is a FAST dual sync. I've called FAST several times but it seems like it takes at least a week to get a response from them.

Are there any other causes for this and any tests that I can perform with out disassembling too much of the motor? If I have to pull the timing cover to inspect the chain I will but I do not want to do that first if it is not necessary.

[camcojb]

what are you seeing that makes you think it's jumping time?

Jody

[John S]

When the engine is timed correctly I can check the timing with a timing light and at idle it runs about 28* and this is matched to the the timing map in the XFI software.
Yesterday I made some adjustments to the suspension & decided to take the car out for a quick run last night. A trip down the road from my house is about a mile (I live in the country) so after turning around at the end of the road about 1/2 way back I jumped on just a bit and when I did it started backfiring. It ran rough the rest of the way home and died when I got in the garage. I got the engine running and checked timing with the timing light and it was fluctuating between 0 - 1o* retarded. Since it was late I just shut it down and came inside for the night. The only thing I did not do which I probably should have was connect the laptop to check and see what the program was calling for.