I have done a little bit of searching on here but not finding anything. I have a 1998 4x4 blazer, when it hasn't been running for over like five hours, or overnight it usually starts up with little to no hesitation, but when it is still warm after like a 1/2 an hour it will have to crank for a couple of seconds before it starts. Or if I start it up after it sits there for 10 minutes tip start fine also. I would think it is the fuel pump losing pressure, but it starts fine after it sits overnight. What should I look into? Any help would be greatly appreciated. Thanks

 

Whatever it is you need to start with the fuel leakdown test.


Something going on after the heat soak, engine off and hot but no coolant running, block heats up so something may be leaking under the plenum.


The test is all over the board, you need a fuel pressure gage, $40 bucks.


Buy one, if you keep this truck you will need it. You will spend more in gas to get the loaners.






Could have something to do with air intake temp sensor.......Long shot, check the leak down, when hot and when cold, come back with results.

 

I haven't had the time to do the test, I am working full time and going to school, so I was at a friends house for a couple hours, when I went to leave it started after a few cranks, then it went up to 2500 rpms, then settled down to 500 for a couple seconds, then it died. It did this a couple of times. I did not want to give it any gas to try to keep it running, let me know your thoughts, thanks.

 

Fuel pump. Do a fuel pressure leakdown test to be sure though.

 

after letting the vehicle sit for a few minutes, remove the intake snorkel at the throttle body, open the throttle plate and take a sniff. if you have a heavy fuel smell then you more than likely have a fuel pressure regulator leak. the high rpm is from the excess fuel. overnite the fuel can vaporize and not cause an issue. Regulator is under the manifold in these beauties