well i took a nice long trip down to quebec city, 8 hour drive, and whole heap of problems. hesitation in fifth...having to drop it down to 4th to avoid hesitation. car shut off as soon as i got off the highway. and car did not start up the next morning. i suspected ignition problem, because i bought the car and engine with the ecu chipped with a spoon chip. i took out the chip, put the stock one back in. brand new distributor, i was running 94 octane gas at the time, and the car barely ran. i drove it till empty 87 octane went in, car ran a lot better with less hesitation....please someone help..hyundai accents are passing me

 

What do your plugs look like? White,brown,black?

 

plugs are dark brown or black, couldnt really tell, dark outside

 

clogged fuel filter? or bad dizzy?

 

well, its running really really rich, and the ecu was flashing code 15. which is the ignition timing. and its a brand new distributor

 

my car had a b16 in it and it had alot of hesitation with it. i changed the plugs,plug wires, and dizzy. the car died on me on my way home from jersey. check engine light was flashing a code 3 wihch was map sensor. i had a problem with my vacuum lines and it totaly fixed the hesitation problem. the car dying was the map sensor though. i tried using 4 dif map sensors and it still kept doing the same thing. turns out there was a short in the engine harness somwhere in the map sensor wires. ran 3 new ones and tapped them into the ecu harness and it fixed the problem. get a shop manual and try testing the pires to the dizzy. it might be tedious but it might fix your problem. if your running a jdm motor this might help.http://www.honda.co.uk/car/owner/workshop.html its the uk workshop manuals. as for the different gas choices, ur supposed to run 93 or better i think. i dont see how that could be your problem. it should run like crap with reg gas in it.