old gas?

[Pete M]

after reassembling everything in Brianne's truck (88 4.0) the idle sounds rough and it stalls out if you rev too quickly, and if you do rev it up, it'll stall once it gets back down to idle.  but it will rev and sounds fine doing it.  Ive fiddled with things, checked my vacuum lines again, and swapped out the IAC with no changes.  the gas is a year old so I'm thinking of grabbing some octane boost and fresh gas tomorrow and see if anything happens. 

[eaglescout526]

I’d smell the gas and take a sample out and see if it’ll light the fumes before dropping in some octane boost. 

[gogmorgo]

Poor response to throttle input is often a throttle position sensor issue. Its also a symptom of a weak fuel pump or other fuel delivery issues although usually closing the throttle will improve things in that case.

I also did once get a distributor put in one tooth out, which was close enough the engine would idle but wouldn’t always stay running and didn’t want to change rpm. But that’s an HO, not a Renix

 

I wouldn’t expect year-old gas to be bad enough to stall the engine but it is a lot hotter down your way and fresh gas can’t hurt anything.

[Pete M]

fuel injectors are new, but I've touched nothing on the spark plug side of the engine.  maybe an injector is bad?

[Salvagedcircuit]

If the fuel was bad, maybe replace the fuel filter. It's easy to get to and cost $3 from rockauto.

[pizzaman09]

I'm not sure what you've had apart, but I'd check the intake and exhaust bolts are tight.  

[Pete M]

dumped in a booster and a couple gallons of fresh gas.  after a bit of the normal struggling (I'm assuming this was burning off the gas in the line), it no longer stalls out, but still lopes. I'll just start a new thread about the idle.