99 Zr2 won't start .... again :(
 

Okay... none of you will remember but in the fall my 99 began having starting issues. Through lots of troubleshooting i discovered it would only start in the cold(below 10 degrees worse below zero) if i sprayed starter fluid in the tb or plugged in the block heater. Either one of those and it fired right up. What ultimately got it fixed was dumping a can of sea foam into the gas tank... that seemed to clean up the gunk that was causing the poppet nozzles in the spider assembly to stick. From that point on it started by itself except one day it was -20 without starter fluid or the block heater.

Lately it's been giving me grief again, needing the block heater to get going some mornings. This week that stopped working. It's not that cold... down to 1 or 2 overnight. Even plugged in it won't start. Starter fluid it almost fires but wont'. I've had to give it a boost the last few days to get it to fire. ONce it's running it is fine if i go into a store or something it will fire up right away again.

So i figured something was draining the battery...so i tested it before firing and it read 12.42 volts. That's pretty normal right? When i turn the key to 'run' waiting for the pump to prime the volt meter doesn't go up as far as it does when i have the booster cables on.

Could it be not enough cold cranking amps now? The battery was replaced in september.

I'm going to try to get a fuel pressure guage to confirm that's not the issue but it doesnt' seem to be. Pump sounds exactly like it always has(mine is LOUD).

Definitely check the fuel pressure. It should be 55-60 psi with key on. (and drop no more than 5 psi in 10 minutes after turning the key off). I learned from my friends 2000 48psi will NOT start the truck

99 4.3L is a CSFI system, it requires 60 to 66psi, key on engine off, pump running, and must remain above 55 psi for 3 to 5 minutes after the pump shuts off. (Straight from the GM "dealer issue" service manual.)

Well i tested the pressure..it was about 48-49 psi :(

Going to replace the filter first... you never know :D Otherwise it's decision time....replace the pump knowing i still need to replace the spider injector assembly before next winter... or get rid of the truck because it's been one headache after another :(

So...how do you get the fuel filter off without breaking that front clip? I understand there's a special tool for them?

Release the two tabs and slide the filter off.

Why do you need to replace the injector assembly?

Because in cold weather the poppet nozzles stick and if i dont' run a can of seafoam through the tank each month i won't start without either the block heater plugged in or starter fluid. :( That was my original problem that started this past fall.

Have you tried an actual injector cleaner? Or a professional cleaning?

If you get fuel pressure up where it needs to be, and run a bottle of Chevron Techron through it, I guarantee it will start better warm and cold. You might find that you don't need the injector assembly replaced. The poppets need proper pressure to squirt the fuel.

Yes I had tried proper injector cleaner(can't find the chevron with techron in canada though)... none of them worked. Seafoam worked great so i used it...but after about 4/5 weeks it would need it again. The only time it didn't start was a -20 day...needed starter fluid that day.

Recently it wasn't starting without the block heater again and eventually not at all. That's when i got the 48psi.

I got the injector assembly for 60$ and i'm going to take it to be professionaly cleaned before installing.