intermittent cold start problem.....now what??
 

Did a search and did the usual tests before asking........

93 Blazer, 4.3 CPI........no codes set

Truck wouldn't start one morning a few weeks ago........cranked fine, checked spark at coil and one plug.....let it set an hour and it finally started.

Week or so later, same thing, wouldn't start in the morning, but started later in the day.

Last Friday, would not start in the morning......tried again Saturday afternoon and it started.

After it starts, it runs fine and will restart without issue.

Finally had a chance to work on it yesterday......truck started without issue........rented a fuel pressure gauge and pressure was 59 psi, key on, engine off.......53 psi engine running......held pressure for over 10 minutes with key off.

Left gauge hooked up overnight to see what happened on cold start.......this morning, gauge showed 0 pressure with key on, engine off.......but truck started and ran fine. Turns out, the gauge stopped working for some reason.......I returned it and swapped it for another gauge. New gauge shows 61 psi key on, engine off.......holds pressure for over 10 minutes.......53 psi with engine running.

So, I still don't have a pressure reading with a completely cold engine, but it looks like the pump and regulator are working correctly??

Any other ideas???

Thanks

You need to figure out what isnt working when it decides not to start. Ensure fuel pressure is present at the time of no start. Then check for spark at the time of no start. If you have both of those then the injector may not be firing at the time of no start. I belive the injector is triggered by the pick-up coil.