backfiring and poor running condition

[onephatz]

now I know it's not a z but it is it's close cousin.

my '82 maxima 2.4L.

 

I recently replaced the head gasket, cam shaft (with z cam),two leaky injectors, and the oxygen sensor. she ran smooth and good before the tear down. now (see below)

 

problem: idling seems ok but does not rev up well(sounds like a miss) and wants to backfire thru the intake manifold.

will not pull it's self down the road with the same problems as above

 

checked:

fuel pressure ok (32-40psi)

tps ok (idle and wot)

afm ok (proper resistances)

injectors working (checked each with a screw driver)

can't find any vacume leaks

ignition is set to stock 8 deg btdc

adjusted the valves to proper tolerances

ignition primary's and secondary's working great (checked with scope)

compression good on all cyl. ~175psi each

 

interesting point: when the injector plug on the #1 cyl is removed you can hear a small difference in the engine but not as much as with the other cylinders. I can definatly hear the injector firing but no difference when unpluged.

 

I am kinda at my wits end right now so any ideas would be very welcome

 

thanks

jesse

[onephatz]

well as it turned out the crank pully turned on the harmonic balancer and was throwing off my timing.

 

my dad(mechanic of 30+year) show me the "old way" of setting the timing with a vacume gauge. he said that at idle there should be about 20-21 inches of vacume. I was setting at ~15. cranked the distributor around and she smoothed out, and reved good.

 

jesse