bogging down when warm

95 rs · Post by **95 rs** » February 4th, 2007, 10:42 pm

my buddies car is a 94 with a 1.6 dohc and when he accelerates when the engine is warm it bogs down bad. i mean it barely goes and it backfires. when its cold it doesnt do this and its an intermitent problem. i have no clue what it could be, i was thinking that maybe his timing was out but we made sure that it was right when we had it at work. i really have no clue on what it could be and neither does he. he needs to know what the problem is so he wont do any damage to the engine since he is going to school soon. so if any of you guys could help that would be great. thanks

Bumpysbro · Post by **Bumpysbro** » February 5th, 2007, 2:31 am

a couple things it could be is a coolant temperature sensor or maybe if he has the stock intake tubing and hoses expand when they are hot and maybe creating a small vacuum leak.

95 rs · Post by **95 rs** » February 5th, 2007, 1:43 pm

but would that make it backfire? like when your in second and you punch the gas it starts backfiring and well it has no power. from about 2000 rpms to 2500 rpms it will do this but anything higher it wont bog down. i donno what it could be its messed up. but when we put some injector cleaner into the gas tank it went away. but when he fills it up it does it again about 100 kms later. anyhelp would be great. ill look for a vacuum leak and the coolant temp sensor also. thanks

ariesdude · Post by **ariesdude** » February 5th, 2007, 2:33 pm

Bad Coolant temp sensor and/or O2 sensor can mess with the timing and produce loss of power and even misfire when warm.

m0rpheus666 · Post by **m0rpheus666** » February 6th, 2007, 6:02 pm

could the coolant sensor or 02 sensor going produce the same affect when cold? My car when it gets really cold out, will start up fine, when i take off in 1st runs fine, go into second and kinda get on it about 1/2 WOT, it will sputter and act like its gunna die, but only does it when cold.

95 rs · Post by **95 rs** » February 6th, 2007, 7:32 pm

pretty much exactly what mine does but only when it is warming up.... when its at normal temp its fine i donno im gonna try those parts and if not i donno where else to go

mab · Post by **mab** » February 11th, 2007, 1:34 am

sounds like a bad o2 sensor after the car wrms up it goes into closed loop then the 02 sensor take over of the fuel control