Bad gas suspected...

I suspect I may have filled up with bad gas. I only use Shell and generally 93 octane (possibly a waste but I figured it couldn't hurt). There is a new Shell station that opened down the road that I thought I'd try out. Now every time I go to start my truck after it's been off for at least a few hours, it has a rough start and seems to hesitate. Truck has less than 25,000 miles on it and is push-button start. After a few seconds of it acting up, it seems to correct itself and the truck performs seemingly fine. My theory is that I got bad gas and the truck re-calibrates itself to compensate. I was thinking about running down to Walmart and picking up a bottle Royal Purple fule treatment (http://www.royalpurpleconsumer.com/products/max-clean-fuel-system-cleaner/) but thought I'd get someone else's opinion. I considered taking the truck to a mechanic and having all the fuel drained but geez that would be expensive.

Thoughts?

 

Go to Walmart and buy a bottle of Heet gas treatment in a yellow bottle. Sounds like you got some water in your gas.

 

Thanks for the input. Could water cause the engine to exhibit this behavior but then seem to be fine after the truck has had a chance to run for a few seconds?

 

Have you changed the fuel filter?

 

Nah. I did add Heet like you suggested and it did seem to help quite a bit though. Thanks!

 

For anyone curious, Toyota claims it was my K&N air filter...more specifically the oil used on it. Seems it is sucking it into the intake and causing issues.

 

i had the same issue , i filled up at a new gas station and it would not exceed 2k rpm and get no power. took it to toyota they blamed the K&N but i had installed it after the problem started to see if it would help . they swapped out the MAF sensor , i ran the tank to empty and filled up ...problem went away

 

Interesting...I'm probably going to purchase a cheap filter and run through another tank to see what happens. Might also use Seafoam to clean the intake. If it continues to act up, I'll at least be able to force them to rule out the K&N. I also have a ticket open with K&N to see what they think.

 

Sounds nothing like a bad gas problem. If it was bad gas then it would be constant and not disappear when warm. Sounds like Toyotas diagnosis is correct. The oil from your kn filter is coating the hot wire on the maf sensor causing driveability concerns. Once the hot wire is at operating temps it can smooth things out a little better but is still not operating 100%. Clean the maf sensor hot wire and then get rid of the kn filter

 

Getting rid of the KN is a good idea. Never really saw much of an improvement from it anyhow...sadly a waste of money. As for cleaning the MAF sensor, how would I go about doing that? Last night I did a treatment of Sea Foam intake cleaner which did seem to help this morning. Before running the treatment, I took a look at the intake tube that connects to the throttle body and it looked super clean. I also removed the sensor and it too looked super clean however I have always heard that they are very sensitive.

One other thing that puzzles me is how enough oil was sucked up through the intake when the filter box lid that sits right above the filter that connects to the intake tube has that secondary filter built into it.

 

It's just need to be a very small amount of oil that lands on the maf hot wire and coats it. Take the maf out and spray it down with some electronics cleaner, basically brakleen that just dries super fast. If you don't have any regular old brakleen should work.