Hey all,

I have an 03 s10 Blazer LS 2WD with 97k miles, for the last 3 months it has been having a rough start. If i were to try to start it like normal it will either: Crank until it starts (4-10 seconds) or just keep cranking to where i give up. However, if I put the key in ON (get the fuel pump running) then crank, it will start after cranking for (4-6 secs). And then sometimes it just starts up fine. The problem is intermittent.

Today while looking under the hood, I noticed the Breather hose that connects to the air intake was disconnected, so I reconnected it. It still is having a rough start but could that have been the problem? Does the computer need to cycle through a tank of gas to re calibrate a proper fuel mixture? Or is the effect of it being disconnected irrelevant? Any information will help!

FYI, I replaced the cap and rotor 4k miles ago


Thanks in advanced!

 

You should do a fuel pressure and leak down test. Pressure should be 60-66 psi and hold at 55 psi or above for 10 minutes after the pump shuts off. This test is done with the key on engine off.

96+ Fuel System Diagnosis

 

I agree with burned "fuel pressure and leak down test"

Curious though... Did you use ACDelco when replacing the cap and rotor? If you used any other brand other than ACDelco then that's where ya need to start. These trucks don't like after market parts.