g3mustang

1988 mustang 5.0 TF stage one cam... when the car is cold and under a load it backfires into the intake. thats what it sounds like... car will go full throttle and runs great. goes away after driving for a couple of minutes or motor gets to normal temp... i havent touched anything to make it do this i got it like this.

g3mustang

i have no codes

g3mustang

sorry idles fine too

zebo87

clean your maf and check your timing.

g3mustang

What do you clean it with?? The maf spray

mjr46

sounds like an open loop lean drivibility issue, and you can do as stated above for maf and timing.....but one thing I'd look into are the ect and act sensor readings when still in open loop, these are two main inputs while in open loop also make sure there are no open or flat spots in the tps.........you'll need a dvom to test such...ect and act work of resistance and tps is a potentiometer that works off a voltage ref and can be tested with the dvom set to volts and measured by back probing the signal wire = green iirc......and going from closed throttle to fully open , looking for any spots that drop off to open circuit

g3mustang

How do I check the ect and act and where are they located

g3mustang

Also why do you think these sensors could be bad when there are no codes... Also stupid question the tps is on top of the throttle body right?? How do you take it out to clean it

02WhiteGTVert

start with the simple stuff...vaccuum leaks...clean the MAF, check your timing!

g3mustang

i cleaned the maf and it didnt do anything... for $20 i just changed my ect and act and that did it... runs great when its cold now... thanks again for all your help