97 Jimmy, no start in cold

[Dr_No]

Originally Posted By: clinebarger
IAT nor CTS sensors go bad on GM vehicles very often.

CPI Injection is very sensitive to fuel pressure, Below 58 psi & the Poppet Valves will not open on a cold start.

Next time it "no starts" Try priming it with carb cleaner through the PCV hose. If it now starts....Fuel System issue.


I appreciate your comment. Now I have to ask how plugging the block heater in for 45 minutes will affect fuel pressure to that degree?

 

[clinebarger]

It could effect Poppet temp, Raising it to the point they un stick.

If you really think it is a IAT or CTS sensor issue....Unplug both next time it No Starts on you, Infinite resistance will read -40F on IAT & CTS.

The CPI/spider injection are notorious for sticky poppets & low fuel pressure can cause cold start issues.

 

[Dr_No]

Thanks, I'll give that a try!

 

[Dr_No]

So it appears the no start condition is getting worse. -14C ambient temperatures today, the jimmy did not start. Upon hearing about the fuel system injectors commonly getting stuck I filled up with a bottle of Gumout Regane High Mileage and the tank is 1/2 done.

Turning over with lots of juice from the battery, first inital few cranks it sounded like maybe 2 or 3 cylinders firing but then nothing but crank, key off one last pop and thats that. I did unplug the coolant temp sensor first under the thermostat and no change, and also the IAT sensor.

The block heater is now plugged in, so in 45 minutes i'm sure ill be able to start it.

 

[Dr_No]

So roughly 40 minutes after plugging in the block heater the engine fired up, still unsure what is causing this.. I really don't think fuel pressure is the issue as a few minutes with the block heater fixed the issue?