Any Ideas??

[MD Chevy]

I am not sure which forum this should go in, so if I am wrong please change it. I am not having any problems with my truck, but rather my 2006 V6 Malibu. It has 89000 miles on it and I just replaced the Shocks/Struts, Air filter, spark plugs and wires. I was running premium in it and decided to go back to 87 octane. Prior to the switch I was noticing a pulsating while accelerating under normal conditions. When I changed the air filter, plugs and wires it helped it some but was still slightly present. Now since I have switched to 87 it is even worse, but that has only been one tank. Any ideas of what could be causing this hesitation/pulsating?

 

The car has been great for the past 6 years, but man do I hate trying to find the exact problem. I know its dumb but it makes me want to go out and just have a set payment and not worry about anything for another 6 years.

[govener71]

fuel filter getting old?

[Silverado4x4]

I asume you dont have any codes? Have you cleaned the MAF sensor? Did you put AC Plugs back in? Some other brands of plugs will cause the problems your having. You may have to do a fuel pressure test as your pump may be getting weak.

[MD Chevy]

First thought was the filter, but in the malibu's the filter is self cleaning and GM doesn't even sell a part for it.

 

I did replace with AC plug, but put on NAPA wires. How would I go about doing a fuel pressure test, pump really never even crossed my mind? I will look into the MAF sensor and cleaning it. Any suggestions on how to do that?

[markw8]

It might have carbon build up from the premium fuel. Go online for a product called BG44k. Buy 2 cans. Put one in a full tank of fuel. Run that tank all the way out and see how it is. If needed do the second can or save it till sometime later. This is much better than Seafoam or anything at the parts houses.

 

Mark

[j13smiley]

First thought was the filter, but in the malibu's the filter is self cleaning and GM doesn't even sell a part for it.

 

I did replace with AC plug, but put on NAPA wires. How would I go about doing a fuel pressure test, pump really never even crossed my mind? I will look into the MAF sensor and cleaning it. Any suggestions on how to do that?

 

 

spray it with electronic cleaner. the wires are very fine so don't touch them with anything.

 

would be nice if you had access to a data logger to see how the car is really running. otherwise you're guessing unless you set a code...

[MD Chevy]

I found a website giving instruction on how to clean the MAF. Thanks for the suggestions. They said to use qtips to get all the dirt/grime out, is that not wise?

 

I will try the carbon build up idea, I would have thought it would be the other way around and 87 would cause more build up. I have ran premium for only about 8 months and then decided to go back to 87 cause gas prices are gonna get ridiculous.

 

I wish it would throw a code, then I could go get it check and fix what is really wrong, rather than shooting in the dark.

 

Any other suggestions are welcomed. Thanks to all for their thoughts on the problem.

[Morgan1986]

First thought was the filter, but in the malibu's the filter is self cleaning and GM doesn't even sell a part for it.

 

I did replace with AC plug, but put on NAPA wires. How would I go about doing a fuel pressure test, pump really never even crossed my mind? I will look into the MAF sensor and cleaning it. Any suggestions on how to do that?

 

how can a filter be self cleaning and if it is why are they not on all vehicles?

[MD Chevy]

Supposedly there is a 'sock' around the filter and it's located in the gas tank. With the gas moving around it cleans itself.

[Morgan1986]

So with the gas moving around it just washes out back into the fuel ? Sounds like not the best setup and would a little bit of gas moving around clean it that much ? Guess it would work . The only time I ever heard a fuel filter been change is on my dads 91 F250. He changed that and what ever problem my dad had went away right away. ok sorry to the OP back to his thing.

[Z71Steve]

I had this issue on my old truck, cleaned the MAF and the Throttle body which was caked in carbon buildup. fixed the problem immediately. I was a premium user with that truck to and when i switched it went haywire.

[Wolfmanjohn]

Self-cleaning socks? That's quite a concept; my wife sure wishes I wore those!