Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Hi, My name is ***** ***** for the delay.
I will do my best to assist you
so,you are saying it will start for a second then doie?
tell me,does the security light stay on?
ok..so it does have a spark?
will it fore with a prime[starting fluid or if you pour a little fuel in the throttle body]?
it should run with the prime if it is in time,,have you test the compression of the engine?
and you replaced all the valves?
it should fire up with a prime...if it does have a spark
yes,,i would think it would fire,,are you sure it has a spark
ok,,if you pull off the ignition assembly..and put a plug in each boot.all have a spark?
we need to make sure,,you may have a bad crank sensor
are the spark plugs good?are they maybe gassed?
sorry i missed you,,
it must have jumped time with the new chain,,there is no reason for it not to at least fire with the prime if it is in time
does the security light stay on now?
please stand by,perhaps one of the other guys has an idea of what is going on here,
someone will be right with you
I'll see if I can give you some further advice.
It does sound like your valve timing is now wrong.
A habit I have is to not just look at the timing wheels to make sure the marks are correct, but to also look at the cam lobes. Cylinder 1 would have the lobes up, a mirror image of each other, Cylinder 4 would be facing down, mirror image.
And the second thing now is if the timing has jumped for some reason, you may have bent valves again.
That low of 120 says something has happened.
Did you torque the cam gears correctly?
"Compression to determine cam position", that would the first engine ever to have that.
Your engine has a camshaft position sensor.
Is it connected, does it show cam and crank speed in data on scan tool?
The engine should run if the valve timing is correct, fuel quality and pressure is good, injector pulse and spark.
The uneven compression is an issue, which puts the MAF value out and hence fuel quantity will be less.
You could also find valves riding (not seating) if the oil pressure is excessive.
If seen engines with 120psi while cranking that won't start.
A few more things.
Be aware that milling the cylinder head near minimum spec or more alters the valve timing marginally (retarded).
And piston to valve clearance could also be marginal.
Also ensure the valve lash adjusters go back in the same bores where they came from.
Hope you get it sorted.