cadillac_bn

i have a 1993 s-10 with a 2.5 4 cylinder it is missing real bad i can pull the 2 middle plug wires off and it doesn't change anything so pretty much i'm only running on 2 cylinders i put new wires,plugs,cap,rotor,air filter,breather filter and pcv valve and that did not change anything but i am getting spark to all cylinders i've checked that i've also tried turning the distributer and that didn't help either it ran verry good up untill that point i just cant figure it out if anyone has any sugestions please let me know i'll try anything to get her goin again!!!!!! please help me!!!!

DAB77

first thing you need to do is a compression test on all cylinders. if you don't have a compression gauge you can rent one pretty cheap at most parts stores. if you have good compression and you have spark at all the cylinders and assuming you have 4 separate injectors, switch the injectors and see if your miss moves with them.try that and post what you have.

cadillac_bn

hey thanks for the reply i'm gonna do a compresion test on it today or tomorow but its carberated so i don't have any injectors. any other sugestions before i do a compresion test on it? thanks

Chris Stewart

It has a Throttle Body Fuel Injection...looks like a carburetor though.
I had the same motor in a 1986 Cutlass Ciera....it's the Pontiac 151cu.in.
Iron Duke motor, tough piece.
You might look at the sparkplugs on the middle cylinders to see if they're fouled or not.

cadillac_bn

i just put new plugs in it and drove it bout 3 days and the 2 inside ones are realy carboned up but the 2 outside pones are burning pretty good someone told me that he thinks my valves are bad and how do i switch my injectors?

Chris Stewart

You have 1 injector body and they're pretty reliable.
Is the air filter oily?

cadillac_bn

it was but i replaced that the breather filter and the pcv valve and the air filter was only about 8 months old