Bad gas - now the car has intermittent sputtering.
 

I filled up about a month ago and soon as I did, the car starting bucking and sputtering at higher rpms/medium+ load.

I used some water remover for the bad gas, but it did not work.

Finally yesterday I got around to draining the tank. Once it was done, I put 2 gallons in and some seafoam to clean out some junk.

I am still getting the sputtering problem... although less, its still there.

Whats next on the list to look at?


Fuel Filter? (was replaced last year)
Spark Plugs? (replaced 2 months ago)

Could these get fouled by bad gas?

measure fuel pressure to rail. i have never heard of " bad gas". maybe something cowinsdently went wrong when you filled up

This is the article I found from Shell.

http://www.nunatsiaq.com/archives/50.../50722_08.html

bump..........

My 400 did the same thing. I thought it might have needed a tune up so I changed plugs, cap and rotor and it still didn't make a difference. I ended up draining the tank, putting in some fresh gas and a bottle of Lucas fuel injection cleaner. Finally it went away after it got all that other crap out of the fuel system.

can never be sure with these things, and replacing all of it is a pita...
could even be the maf needing cleaned...anything Air/Fuel related. . .

I would fill it with 91 octane and take it down the interstate for about 50 miles turn around and come back. If this does not clear the problem go get your injectors cleaned

instead of seafoam, use Techron (made by chevron). More concentrated cleaner and does wonders to cleaning the fuel system. Also change out your fuel filter after using the Techron to clean out the system.

I had a car sit for 3 months and did the same thing because gas does get bad with time. I ended up getting octane boost till I filled up again

Okay Im not sure if you guys read the first post well, lol. I said I drained the tank (all bad gas) and filled it with new gas. So its no longer the gas problem.

It comes down to everything that touched the gas... Fuel Filter, Spark Plugs, or Injectors.

I did read that, but depending on how far you drove it after the change would make a difference I would think. The lines, filter rails, ect. still contain a bit of fuel. Have you looked at the plugs? Are they fouled? How about the spark coming from the coils? I even went as far as unplugging one of the coils at a time while it was running to see if it made any difference....BTW they bite with a vengeance if you accidentally bump into them with your bare hands... lol. Good luck man.

Thanks for the reply... THe new gas is about 2-3 weeks new... a few fill ups later... so its not gas anymore.. the problem spread.

I am pulling the plugs today to look.

you ever think it could be your pump wiring?

My car sat for more than a year, and i'm sure it had regular in it. When i turned it on, it ran without a stutter first try and drove to my house, where I burned off all the gas, and just filled with premium and ran seafoam through it to make sure the system was cleaned.

I also changed plugs and fuel filter. No sputtering issues. However I did replace the fuel pump for my swap, and I did hardwire it to the battery.

While you're under there, clean up the back fo the throttle body and check the intake mani for soot build-up. If you can do a fuel pressure test then do that as well.

Negative on the fuel pump and the coils/ignitors