My 2002 Chevy Blazer 4.3 Vortec V6 4WD is hard to start. When you turn over the engine it may crank for 10 seconds and the engire will not start. Then on the second attempt to start the engine will start but idle very rough (200 RPM or so) after 5- 10 seconds of rough idling it will idle normal (700 RPM) and everything runs fine. If you shut off engine and immeadiately restart engine, it will crank on the first attempt and run fine. If the engine is left to set for more than 30 minutes to an hour problem starts again. This did not happen until last week when I bought fuel injector cleaner and placed it in my tank. The very next day this started and also the engine would lurch when driving down the road and you would be giving constant throttle and when you let off the throttle to coast the engine would lurch very badly causing whole vehicle to shake, thought it may have been a tansmission problem trying to downshift gears when I left off of throttle. I took it by my mechanic, he hooked it up to the computer, only two trouble codes for two misfires on two different cylinders, and he even said they were old. No misfires, air fuel mixture was good and being regulated, O2 sensor good, air sensors behind both catalytic converters were showing good exhaust flow, no transmission codes??? The lurching stopped after that day but the starting issue is still here. For the past two weeks since this has happened and while it is going on, it has been very hot and humid here. Any thoughts?

The first thing you need to do is check fuel pressure with a fuel pressure gauge. The test port is on the fuel railbackby the firewall on the drivers side of the engine compartment.

I have a feeling you will nit see fuel pressure hold steady with the key off as it should. With the symptom you described, which is known as an "extended crank", I wouldn't be at all surprised if the fuel pressure regulator is leaking. The regulator is located on the backside of the CPI unit wich is located under the intake plenum.

If you any any questions about this or would like some more details about what I described above let me know and i'll be happy to help. The first thing you need to do is check fuel pressure with a fuel pressure gauge. The test port is on the fuel railbackby the firewall on the drivers side of the engine compartment. I have a feeling you will nit see fuel pressure hold steady with the key off as it should. With the symptom you described, which is known as an "extended crank", I wouldn't be at all surprised if the fuel pressure regulator is leaking. The regulator is located on the backside of the CPI unit wich is located under the intake plenum. If you any any questions about this or would like some more details about what I described above let me know and i'll be happy to help.

Thank you airjer995 I have been reading about the pressure and the regulator..I was also thinking either not getting enough pressure upon start up or too much pressure after shut down causing fuel to leak into the cylinders thus becoming dead when furst starting up?

Gas is good....have cycled through two tanks since this started....had a full tune up not more than 2 months ago, plugs, wires, cap, rotor, pcv valve and fuel filter.


Leaning more towards pressure regulartor, injectors, or possibly fuel pump itself not priming...

Thanks guys...anyone with more comments keep them coming! Thank you airjer995 I have been reading about the pressure and the regulator..I was also thinking either not getting enough pressure upon start up or too much pressure after shut down causing fuel to leak into the cylinders thus becoming dead when furst starting up? Gas is good....have cycled through two tanks since this started....had a full tune up not more than 2 months ago, plugs, wires, cap, rotor, pcv valve and fuel filter. Leaning more towards pressure regulartor, injectors, or possibly fuel pump itself not priming... Thanks guys...anyone with more comments keep them coming!