I had a horrible oil leak at the back of my HSR and finally resealed it but now I am running pretty lean, getting backfiring when I close throttle at higher rpm's and the O2 sensor shows lean at cruise. There was no sign of leaks at the runners and the oil leak appears to be gone and I was kinda expecting it run rich with a good seal. Any reason for it to run lean after resealing the intake if everything is set up correctly?

 

Find if I pull timing out it does not sputter/backfire but I am at a loss as to what is causing it. I triple checked the timing to make sure I had it sync'd to my Accel FI plus wire routing and changed out the plugs along with the ign module on my new Summit dist. I am wondering if the last tank of gas I put in before parking it in Feb and doing the reseal might be bad/watery. Running some fresh 93 oct but still getting the sputter when I try to run adv over 40 deg at cruise for fuel economy, might put a new fuel filter in it and some dry gas and see if that helps.

Any other ideas?

 

Too much base timing maybe???

 

I triple checked the timing on the balancer against the 16 deg map (all cells = 16 deg) I have for setting timing and it was dead on. I do wonder if somehow it is off but I have used the same method prolly 10 times before with no problems. When I drop the timing at idle too low (less than 8 deg) the car acts like it wants to stall so I think I have it set up correctly. It has got to be either the dist or bad gas.