plz help 97 gmc sonoma p/u wont start

[ads8613]

I have a 97 gmc Sonoma pick up with 4.3 it has good blue spark 65lbs of fuel psi but wont fire ive put new cap, rotor, plugs, control mod, pickup coil , crank sensor, new timing chain and gears because thought it might of jumped time but didn't but put new chain and gears on while I had it tore down im lost plz help I don't know what else it could be

[Jsdirt]

Well, you've got spark, and fuel .... so the only other elements needed for the pistons to party is air, and compression.

 

As a betting man, I'd recheck your cam timing on that new timing set ....

[ads8613]

all timing marks line up at 6oclock and 12 oclock made sure was on right stroke top dead center have 160lbs comp give or take on all 6 cyl no air or exhaust restrictions

[Jsdirt]

How about ignition timing? Rotor 180° out of phase?

 

If not, check the crank and cam position sensors.

[aflesch]

IIRC that engine has the spider injector setup. The capillary tubes get plugged up on them and it won't run. (remember: just because you have pressure doesn't mean you have flow) Does it do anything when you crank it? (sputter, backfire out the intake, etc)

[ads8613]

no it don't do anything not even with starting fluid timing is dead on ive already checked to make sure im not 180 off

[aflesch]

I think it might be time for some advanced computer diagnostics. You could have a wiring issue or a PCM issue. Have you checked all the fuses?

[Jsdirt]

If it don't fire on ether, then you have no spark or no compression - no 2 ways about it. Check those aforementioned sensors.

[ads8613]

fuses are all good comp wont tell me anything already tried bout ready to take a stick of dynamite to it lol im lost ive been a mechanic for 15 years and have never had this much prob fig something out

[Jsdirt]

Oh I hear ya brother. This is why my next "new" truck will be built before 1973.

 

Good luck on your diagnosis.

[ads8613]

fuses are all good comp wont tell me anything already tried bout ready to take a stick of dynamite to it lol im lost ive been a mechanic for 15 years and have never had this much prob fig something out

[ads8613]

oh the days before the screwed everything up with computers lol wish they would do away with them

[aflesch]

"Crank no-start"s are always the hardest to figure out. Could be CKP or CMP like JSdirt suggested. It could be a MAF problem, plugged air filter, plugged CATs, fuel injectors plugged, or like I said earlier a wiring or PCM issue.

 

How fast does the fuel pressure come up when the pump primes? Does the needle creep up slowly or shoot up?

 

Try dropping the exhaust before the cats and starting it.

 

What kind of scanner do you have?

[Gone Again]

Is your "good blue spark" at the plugs or at the coil. You didn't mention plug wires at all. Coil wire OK?