engine wont start

[chevy 2500 1989]

chevy 2500 4x4 5.7L 200,000 miles

 

truck won't start,

engine turns but wont run

 

tried jumpstarting

checked wires, plugs, rotor, cap, coil per chilton manual

 

Diognostic trouble codes:32 (egr valve, I put a new one in 3 months ago),

42 (Electronic spark timing)

 

Does anyone know what the Electronic spark timing does?

 

I have a spark at the sparkpluggs

and fuel coming from injectors

have air, battery is new

 

 

i was driving the truck (use it daily 10- 25 mile drives), I turned off the truck for the night, then tried to start it the next day and it wouldnt start. havent had any problems except for the egr valve I replaced 3 months ago

 

I am wondering if this is a ECM/PCM computer problem.

 

any suggestions

[herrbreit]

have similar problem with my truck. checked everything out have 62psi pressure to fuel rail, spark to plugs , clear air intake.

truck turns over fine but wont fire. happened twice b4 and after towing to shop the mech checked all the usual issues and when he cleared codes and turned it over to check what codes reset the darned thing started and ran.

he didnt charge me anything except the tow fee and told me he was at a loss to explain why its just up and started.

its a chevy 1500 5.7L vortec. the only issues that occur b4 the wont start issue is it starts running a bit rough and gives me hessitant shifting b4 i turn it off and it wont start. its makin me nuts trying to figure this out . the only code its giving is an evap code which i dont believe will not let it start and run . HELP