fuel injector on a 240

Heres the basics,
After putting cheap gas in it I have very rough idle in all gears at about 700-
2000 rpms.Low power on the freeway (I have to drive it)
I have put an injection cleaner in the tank as well as a full tank of 92
octane, hoping it would clear but after driving about 15 miles on the freeway,
it didn't.
Three questions:
Is it a fuel injectior ?
Can I look at the spark plugs and determine which one is bad?
Something else?
Thank you Rojo

 

Could be a lot of things, first thing I'd try is replace the fuel filter,
where that is depends on the year of the car, next check the injectors, if
it's LH-Jet you can remove the whole fuel rail, unplug 3 of the injectors
and point the connected one into a jar while someone cranks the engine.
Check all 4 and look at the spray pattern.

 

Bad gas usually won't hurt the injectors. If its truly bad gas, then there
is probably water in it and you need to remove it with some
non-alcohol-based product.

 

Cheapest and easiest thing to do is to first follow Fred Flinstone's
suggestion and use some "Redline Water Remover and Antifreeze."

Removing ALL the gas by hand from the tank could be next if first
suggestion doesn't work.

Next stop might be to replace the fuel filter. But it wasn't
necessary in my case.

 

Sounds like the timing belt may have jumped a tooth. One tooth off willl
make a drastic diffirence on a B230. Have the timing checked. If it is not
withen specs, the bellt jumped. Replace the belt.