[syclone]

I was driving my 90 blazer w/4.3 and never had any issues. I parked it monday afternoon. 1 week later on monday morning I have a crank/no start issue. Here is the thing that has me stumped. I have spark, I have good fuel pressure and the injectors are working, the timing is also there so what else can it be. I have tried a known good map sensor and oxygen sensor and will be trying a coolant sensor tommorrow but I don't beleive it is any of these. It really wants to start but then either pops thru the throttle body or every now and then thru the exhaust. It really acts like it is out of time but it isn't. Did a compression check and lowest was 130, highest being 142. I was thinking a head gasket failure but not sure now. Any help is greatly appreciated.

 

[underdog305]

Head gasket??? Check your oil. Is it milky white? Radiator fluid low?
It sounds to me like it's something goofy. An easy fix when you find it.

Could it be a bad cold start injector? Just throwing out possibiltys...

 

[Bumpstick]

Might also look under the distributor cap...? Possible cracked cap or...? (internal arcing...?)

 

[milner]

a couple of things to check, make sure there is spark at the plugs. 4.3 v6 has problems with coil towers burning through. are the injectors dumping fuel while cranking. from what you are saying about it popping when cranking, sounds to me like it's flooded. i don't know how cold it gets there, but a fuel injected engine will flood very easy if it does not start right away. hope this helps,

 

[454me]

I agree with the flooding. The newer motors with fuel injection are a bear to start when they get flooded. It could also be some water in the fuel. Try some fuel additive (heet) and see if that helps. I have my geo flood where it took 2 days to get it started.

 

[curly5759]

Is it the Vortec engine?

If it is the Vortec engine, better check the fuel psi again . Absolutely critical on that engine. Specs are 58-63 or so.

If it is the TBI engine, check out the coil wire for arcing as suggested.

 

[syclone]

I have everything where it needs to be to run so I have come to think flooding is also the issue. But why? IMO maybe a sensor like the cts is telling the ecm it is -20 outside and asking for more fuel to compensate. Does this sound logical?

 

[milner]

it could be something like the cts. was it damp out when it sat for a week. could be wires arcing caused a no start. im assuming it is tbi, try disconnecting the injectors and pore some oil down the throttle body and turn it over a few times. if it is flooded, it probably has the cyl's washed down. hold it to the floor while trying it. i don't know if this is helping or not, just grasping at straws here. good luck.