I have a 02 ZR2 blazer 5-speed. The problem im having is for one, It will not start 98 % of the time without adding some gas into the intake. The other main problem is that it really hesitates when under load ( getting on gas, up a hill), and it does this mostly all the time. I have replaced fuel pump, filter within last 6 month and changed out pcv, spark plugs, dist. recently. What could be giving me either problem ?What might i want to check first ? The truck has 155,000 and besides those few parts and some ball joints I haven't had to replace anything else.

 

I would clean the MAF sensor, throttle body, and EGR valve. Do them all and see how it runs.

 

It turned out to be a bad fuel pump. I had replaced it with a autozone pump about six months ago. We had pressure checked and was low. So we replaced pump with another autozoner because it still had warranty, and it runs great. I will however clean the T.body, EGR, mass air flow because i know they could use it. Thanks

 

Good luck with that pump. Hopefully you will not have to replace it again in 6 months.