Ever since I put in some gas at a station in Alabama my car has been backing off on the timing big time, especially when pushed, getting worse as the rpms rise. It feels as if I am pushing against something, or the car is running lean.

I began to think it was bad gas, but since then I have filled up 3 times, and the problem keeps returning. I notice it also when I push the gas at lower rpms, it feels as if you are pushing against a blockage, like when I had a flex pipe collapse on a Maxima I had years back. My car has no flex pipes though, and the mods are listed in my sig.

Tomorrow I will put it up on a lift and make sure there are no problems with the exhaust, but I am doubting that's the problem. There is NO SES light.

I wondered if the knock sensor went bad, or sensitive, after, hitting a rough spot in the pavement, accelerating up the on ramp, as it started acting up shortly after the bumps. That was also just after I put fuel in, so who knows.

I confirmed the issue at the drag strip, where I was headed shortly after, as my traps were down by 2-3 mph. After letting the car cool down, I ran a new best 1/8th trap of 82.98, only to feel the car back off again in 3rd and 4th.

Has anyone experienced a problem like this, without a SES light?

 

have knocking when I dont use 91 only noticeable at low rpm

 

I only use 93 octane. When it acts up, it feels as if it is running very lean.

After checking the car on the lift, the next step will be to get the fuel line recall done, and have them check the tank and filter while it is down. It doesn't sputter though, and a SES light should come on if the fuel system has an issue.

The next step after that will be to check the O2 sensors for build up, and possibly replace the knock sensor.

I hope I find it before that though.

 

Did you figure out whats going on... I am running into the SAME EXACT Thing!! please fill me in!!


Chad

 

Do you have any intake leak?

Don't test pipes set the SES light?

 

Dont think so.. I have been having this problem for a little while now. No test pipes either.
I may have an exhaust leak....

 

An exhaust leak wouldn't case the engine to run lean/rich or missfire.

 

I havent dynoed the car yet so i dont know for sure if its running lean.

I did start noticing weird things after i wacked my exhaust while driving on the highway, it was right after i lowered it!!

Do you guys think the best thing would be to buy UTEC?

I can reset the ECU but how long will that last??

THanks

Chad

 

The lean spot has been slowly fading away with each tank of gas, so I am pretty sure it was bad gas, slow to work it's way totally out of the system. I still notice it on occasion, but not for long, and not very often. I had this happen once when the car was stock. It's much more pronounced with the current mods.

Everything else checked out ok.

 

Hope thats all it was Warren. Isn't three tanks a long time for bad gas to last?

 

The fuel filter is in the gas tank, it might still be glogged by what was in the bad gas.

 

I am going to have it checked when the fuel line recall is performed.