I drove out to Rhode Island with some friends on Friday night (got bored in Queens lol) and before I left my brother put gas in my car and he decided to put 89 octane in it instead of 93 like I told him because I have an JWT ECU upgrade. Anyway on the way there I hear this knocking sound coming from the engine and this it starts this slow hesitation like an engine was acting up or something. I wait till the tank gets a quarter full and I put about 15 dollars of 93 octane in it. It goes away for a while and then comes back. It drove fine on the way back until I got back to The Bronx area and then it started again a lil bit so I drove it around till it hit E last night and then put in 15 dollars 93 octane. It ran fine this morning and then it started the knocking thing again. Anybody knows if I really screwed up something or is it just because there probably is 89 octane in the system and I have to fully burn it out? I was thinking the ECU probably would have to adjust the A/F ratio again from the o2 sensor being that it had 89 octane in it for a while and have NEVER ran 89 with that JWT ECU. I'm hoping I don't need a new o2 sensor or a new ECU

 

Nah.. check your timing and dial it back a couple degrees if it's past 15.

do you guys still use that oxygenated gas up there? If so, that may be causing some of the probelms.

 

The JWT ECU brings up the timing about 4-5 degrees and I never messed with the timing since I've gotten the car (jan. 02). The only way I can set the timing back is if I unplug it and just run my original ECU for a few hours until I burn out all of the lower grade gas. As for the gas Matt, I honestly don't know. I have to find out. All I know is that we run 10 % ethanol in our gas up here.

 

Yeah, oxygenated gas is around......depends on the brand and/or specific station. I don't think the VE likes it. MTBE is the most common oxygenator I've seen. Mmmmmm....carcinogenic watershed ruiner.