Bad fuel or something more sinister?

[the_don]

today i stopped by one of our local "budget" fuel station and put about 71/2 gallons of the regular stuff in the tank and immediately after i found that i could not get the engine above 2 1/2 tho. rpm with it in gear, with it in netural i can rap it all the way past 5 grand. being less then 500 feet from one of our shops i pull in and quick check shows TPS, fuel pressure, and ign to all 6 plugs good. so i take the Chance and drive it the 20 miles home and notice the hotter i get the engine the better it runs, instead of choking at 2 1/2 grand it will start to choke about 3 1/2 grand after pulling the canyons in third(with a very pissed off line of traffic behind me). so before i start to taring in to my only daily driver has any one experienced bad fuel and what was it like?

 

[xlt1993]

First thing I would do of it were me is pull codes from the pcm of the check engine light is on. My maf is wacky and causes this issue with the engine under a load and loses power and it jerks and bucks around when I get on it. Some days mine does that and some days it doesn't. If all checks out with the pcm then I would buy a can of dry gas and drive it around the block a time or two to get it mixed into the fuel and let it sit over night and see how it goes from there. If that doesn't work then i would look deeper into the problem. Haven't replaced the maf yet as its 77 bucks from the parts store and i don't have the money but its the next investment in making on mine.

 

[2stroke]

I have noticed this exact problem from bad gas. Good old ethanol gas. Some claim its just fine, some claim its poison to an engine. The truth is its just fine for a couple of months. Bad gas will cause all kinds of problems from not revving out, to not idling. Really bad gas can cause detonation, running lean, or even cause corrosion in fuel lines. Left long enough, ethanol gas will form a white chalk. The new carb cleaners are "eco-friendly" and wont even touch the stuff.

Just fill the tank full with the highest quality gasoline you can buy. Run the tank as low as you dare, and fill up normally. Its too late for stabil or sea foam or anything like that. They only prevent break down, not reverse it.

 

[the_don]

so i pulled the codes KOEO= 116,114,528.
please keep in mind, it is cold and ambient temp is about 10degf.

 

[2stroke]

116
(O,R)
Engine Coolant (ECT) sensor out of range - ECT

114
(O,R)
IAT sensor out of range - IAT

528
Clutch Position Switch Circuit Failure
C


114, and 116 are both very important sensors. You can unplug them and if it runs good, the sensors are bad. You can also test them with a multimeter. 528 probably just means you didn't push the clutch in when you did the test.

 

[the_don]

528, i never connected the clutch switch to the ecm when i did the auto to man trans swap

 

[the_don]

so unplugged IAT&ECT sensor before driving to work, still no change. going to reconnect fuel pressure gauge, and route through window for the drive home.

 

[Number4]

Bought gas at ARCO in California once, 15 years or so ago. Last time I've bought gas outside of Valero, Shell and Chevron (No Union 76 in Ga.)

At the time, it was my 88 S10 w/4.3. It started running like crap almost immediately. How does one make 'cheap' gas? I suppose you don't put additives in it.

It took me two tanks of premium (regular octane, just not cheap gas) and fuel system cleaner to get it to run right again.

Things tend to fail on cars whenever we do something different to them. Such as a different gas station or some type of repair. The new issue never has anything to do with what was just done, but we always want to think so.

Take your car in because the headlights went out, alternator fails while in the shop. Car owner blames the shop, but it was just a freaky coincidence.

 

[2stroke]

I'm still thinking it's just bad gas.