I bought a 2000 Chevy blazer from my mother in law that had been sitting for 10 years (had a leaking fuel line when it was parked) got the fuel line fixed, replaced gas tank, new fuel pump, and plugs and wires. When I first got it started the only issue it needed was a throttle position sensor, got that fixed and ran like a top for a couple days… now it’s starting to idle rough, when I give it gas the rough idle goes away, if i drive it like normal there are no issues. If I come up to a light it idles rough. I have not done a fuel filter, not sure if that’s what is causing it, however I did notice when I was doing the spark plugs that the distributor cap housing was stripped there for it was able to move around; got a zip tie around and it to keep it down but still idles like crap. Anyone know where I should start next,

ps. Also noticed that the lower the gas gets passed half tank, the worse the idle is, thanks.

 

Start with the fuel pressure leak down test in the sticky and get a proper AC Delco distr cap on that thing.


George

 

Mine used to idle rough, needed just a few more RPMs to be smooth. Then, either it fixed itself or I got used to it. Or maybe it improved after I replaced the vacuum hoses under the drivers side hood hinge, IDK.