91 sunbird 2.0L with engine backfire

[djmherrera]

so i've taken my car to get smogged. good on emissions. but on the dyno "uphill" test it acts up when trying to do 25mph "uphill". she usually only acts up when inbetween first mark and middle on temp gauge. i changed the ignition coil. found a vacuum leak and changed that hose. cleaned carburetor. tuned up. also after he tested it while still warm i stepped on the gas in park and heard almost like a rattle and pop. then the car died out. really would appreciate some help getting an idea of the cause. only have a couple more weeks to smog and just want tina(my sunbird) to pass and run well =)

 

[melsg5]

how about the distributor cap, rotor, and plug wires and egr valve? how many miles on the engine? have you done a compression test?

 

[djmherrera]

i did have the wires changed about two months ago. but i will check the distributor and egr valve. where is the valve located? my guy did check the compression and said it was good. she has about 172k miles on her.

 

[92 Sunbird LE]

No Check Engine Light ?

Water in the fuel?

What spark plugs? Some other people had problems when using other than AC Delco plugs on these motors.

The cam and or rockers are also known to get flat spots on them. (causing backfire)

It may be the tempature sensor is bad and telling the computor to send too much fuel. (like in the morning or when the motor is cold when it really needs more)


Probally needs to go on a OBD1 scanner or laptop with the correct cord and program that will show reatime what the car is doing while driving.

Some shops should still have them if they do alot of emission work.

Hard to find anymore for the general public ( auto parts stores) OBD2 is the norm now.

Doug in P.R.