Genesis sedan 2009>

[09 Gentleman]

How to fix or what to fix when your Genesis loose power?

 

[jmac404]

Is there a check engine light? Have you pulled codes? Is it missing/stuttering? We need more info please

 

[09 Gentleman]

Is there a check engine light? Have you pulled codes? Is it missing/stuttering? We need more info please

Hi jmac404, only thing is a engine light on dashboard. And when I sit on the side of the road for 5 min. It will return to normal driving. For a couple miles or maybe more then loose it again. And no I don't have the means to pull codes sorry. I did take it to a dealer and the clean the throttle body and map sensor? Problem still continue after leaving the dealership. The code they got was a lean or improper air mixture?

 

[jmac404]

First thing to do is pull the check engine codes. Most parts stores will do it for free. And post the codes here.

 

[09 Gentleman]

First thing to do is pull the check engine codes. Most parts stores will do it for free. And post the codes here.

Ok

 

[mikec]

Next time it happens, pull over, pop the lid off the gas cap filler, and listen. If you hear a loud electric motor whirring sound, then the fuel pump is dying, there is debris in the fuel tank clogging the fuel pickup making the pump strain to do its job, or the gas cap poppet valve is jammed shut. As you drive and suck fuel out of the tank, the valve in the gas cap opens every so often to let fresh air into the tank making up for the fuel volume. If that valve doesn't work, vacuum builds up in the tank (as fuel is removed) and the fuel pump then struggles to do its job. Open the gas cap while the engine idles in this no-power situation... if you get a big air rush sound then the tank had excessive vacuum. Try a test drive - if power is restored for a few minutes I'd get a new gas cap first. Drive with the cap not screwed down much - so air can get past it. If you can drive for more than 10 minutes/miles or whatever normally causes the problems that's proof the cap is bad. If it really is just 10 minutes or 10 miles though that is more likely the fuel pump; you are not going to burn much gas that quickly to create massive vacuum inside the tank. Fuel pumps, when dying, tend to run hot. That heat makes their guts expand, jamming the parts that are supposed to be spinning.

A "lean mix" error code means not enough gas was getting into the engine relative to the amount of air. Low fuel pressure can cause that. Big vacuum leaks in any of the rubber hoses under the hood would do that too. Some under-hood hoses are "inactive" until the engine warms up; if those hoses had leaks nothing would happen until the engine was warmed up and they were activated... the engine would suddenly loose power in this case. Few vacuum hoses are large enough though to really affect the engine if they leaked. I'd still bet on fuel pump and/or gas cap issues. The mechanism that measures air flow into the engine could also be having issues - reading lower than it should (or air is getting into the engine downstream of the sensor so the sensor doesn't measure it) and thus the computer commands too little fuel. This is what the dealer techs seemed to think was the problem based on them cleaning the MAP sensor (Manifold Absolute Pressure sensor: this reading combined with engine RPMs can be used to compute airflow) and throttle body stuff. That seems to be a common "first thing to try at fixing engine issues" at many dealerships by the way... rather than actually debugging the real problem.

mike c.

 

[09 Gentleman]

Thanks Mikec, I did manage to get it from cortland NY to Syracuse yesterday. I had to drive the back roads. Left it at a mechanic shop won't open til Monday. I will relay your message to see if that what the issue is.

 

[jmac404]

If it's running lean and throwing codes you need to quit driving it until this is figured out