S10 Won't Start

[JWhitcomb]

I have a '92 S10 Blazer that won't start most of the time. Sometimes after it sits for a few day it starts right up. However most of the time I have to spray starting fluid into the air cleaner. Once it starts it runs fine. Most of the time if I shut it off it will restart as long as it is right away. Wait five minutes and no go. Sounds like a fuel delivery plus computer problem. Any suggestions?

 

[Gizmo 007]

sounds like a fuel problem to me. Like maybe there is a leak in a fuel system somewhere allowing fuel to drain back to the tank? Not sure if there is a drainback valve on those or not. If so, it may be stuck open. Maybe your fuel pump could be losing prime?

 

[Will24]

Try a new fuel pump relay first, but get one from the dealer! I have seen more than a few NEW bad aftermarket relays

 

[JWhitcomb]

About the relay, can someone tell me where it is located and what it looks like? I assume the tank has to be dropped to change the pump. Thanks

 

[HoleshotHolset]

What is the 8th digit of your VIN?



If it's a "W"... you have the CPI (Central Port Injection)... . or the REAL Vortec engine.



If it's a "Z"... you have the TBI (Throttle Body Injection) engine. Interestingly enough... the "Z" designation also represents the Syclone/Typhoon turbocharged/intercooled version of the 4. 3L... . which is batch-fire, direct multi-port injection.



You might want to check fuel pressure... . The Vortec CPI needs at least 35 or 40psi... . the TBI needs about 13psi. If you're WAY off... then you have issues.



The CPI is notorious for injection issues... . I actually have an entire Vortec intake with injection system in my basement... collecting dust. They have one big injector with 6 separate poppet valves to deliver the fuel. The setup in my basement has about 70k miles on it..... if you need it, let me know.



I have a lot of experience with the TBI, CPI and turbo versions of these engines... . and obviously the trucks themselves too.



Scan-tools are next to useless for these trucks... but with any luck we can get you going.



The fuel pump relay is on the firewall - right by the brake booster... . there will probably be two of them there - side by each. And for the life of me, I can't remember which one is which.

If there's only one... . you found your beast.



If you cycle the key to the ON position... without cranking it over... . the pump should cycle... then shut off. If it doesn't... you have issues.



The tank has to be dropped to do the pump. The good news is that both pumps are readily available just about anywhere... . and both part #'s fit a LOT of cars (they're not expensive). The TBI pump fits pretty much EVERY TBI engine... . from the 2. 2L... all the way up to the 7. 4L and the CPI pump will fit a lot of TPI 5. 7L's and some of the other multi-port injection cars/trucks.



Don't overlook the fuel pressure regulator..... a lot of fuel pumps are replaced when the regulator itself is the culprit.



Give us as much info as you have... . email or PM me if you have to.



Matt

 

[HoleshotHolset]

Any update on this issue?



I hope you got it going...



Matt

 

[illflem]

I have a 4. 3 Vortec with 1200 miles on rebuild, '92 Jimmy it's in was totaled last week. That will fix you right up. Cheap.

 

[JWhitcomb]

Update

I found the relays and haven't had time to do anything yet. For the record, it started right off after sitting overnight. Drove it twenty miles, turned it off and it would not start without spraying. Later it started two times in a row after being off for less than five minutes. The battery voltage registers about nine volts when I turn the key on and as soon as it is running registers about fourteen as you would expect. I have pulled the battery and charged it but still says low when the key is first turned on.