I have a 93 S10 with 4.3 CPI, that won't start when it is cold out and if the motor has been running. It acts like it isn't getting fuel. If the temp outside is 35 or warmer, it starts fine. Also if the engine has been running a while, it does the same thing. It has a new fuel pump and filter. New wireset and distributor cap. I checkedand it is getting spark. The fuel pump turns on with the key, runs 2-3 seconds and runs while cranking. Could this be a relay problem? Or something else. I have called every mechanic in my little town and nobody knows. PLEASE HELP ME, I need it for work.

 

How have you determined that it isn't getting fuel? Did you put a gauge on it and experience the problem while watching the gauge?

 

Also check your ICM. It controls spark timing.

 

I haven't had a chance to put a pressure gauge on it yet because the first day I had to work on it happened to be Sunday and nobody was open to get one. Hopefully tomorrow though. I forgot to write that it also hesitates from a stop and bogs down when accelerator is pressed hard while driving.

*Combining Double Post*

I posted earlier with the "not getting fuel . . . " and I guess I worded it wrong. It is not starting when the engine is hot or cold. If the outside temp is around 35 or above it starts first turn of the key, anything below and no luck (although the other day it was 18 degrees and just ona whimI tried it and it started right up. Drove it a while, let it warm up and shut it off, andI was back in the same boat, no starty upy). But if I have driven it for a while and shut it off, it won't start either. It seem to be not getting any gas. There seems to be abundant pressure at the schrader valve, but haven't been able to put a gauge on it yet. The pump is new, filter is new, dist cap and wireset are new. There seems to be sufficient spark. Also when running, it hesitates or stutters from a stop or when revving engine in park, and bogs down bad when accelerating. Could this be the fuel pressure regulator, or perhaps the relay? Fuel pump operates correctly, so that makes me think the relay can be ruled out.

 

what about the coolant temp sensor?

 

Finally had a chance to put a fuel pump pressure tester on and it only would make it to 45 lbs, and then the relay would kick it off. So I think tomorrow i may change the relay and see what that does, unless anyone else has a better idea. A light spray of starting fluiddid manage to get it going today though, ran fine once it started too. Couldn't believe it didn't start on it's own, it was 45 degrees today.