Hard start after truck is warm

[04yellowjimmy]

Hello, im new to this forum and have been having this problem for the past few months. truck starts good cold after sitting overnight. If i go for a drive for a half hour then shut the truck off for 20 mins and go to start it, it takes a few seconds longer to start then runs good. if i run the key to on and do that three times it starts good too. its a normal crank every time never slugish.

work thats been done the past year:

regular oil changes
plugs cap rotor
brand new spider
fuel pressure tested for the pimp and regulator and both were good
new engine coolant sensor map sensor
fuel filter
cleaned maf sensor
check for vaccum leaks
new o2 sensors
battery
starter

im stumped sorry for the long post

 

[Jason6937]

What year is your Jimmy and how many miles

 

[04yellowjimmy]

Its a 2004 and has about 265000 kms

 

[Jason6937]

Maybe check the distributor for excessive play in the gears and replace it. Possibly needs the timing tightened up a bit

 

[Kess]

I'm having same problem on a 2000 Jimmy 4.3 Vortec,,,but. have not changed the Spider,,,don't believe it is bad, have good pressure and holds pressure for over a hour. Starting to think what Jason said, timing could be a little off..
Sure is frustrating.....

 

[Kess]

On my 2000 Jimmy wih hard start after warm problem,,,mechanic has tried spraying cool on the PCM, (computer), and it starts right up afer warm,,when cold, if you apply heat to PCM, it is hard starting...Have sent PCM to A-1, and got it back, same problem...Wondering if they checked it when hot? or warm? Think will send back to them.