'79 280zx

[TheNuisance]

My 280 has an almost flawless origanal body and paint, but the motor could use some help. When i bought the car it had an awful backfire through the Intake.(especially when first started) I touble shot and replaced the Mass airflow sensor. This made a big difference. now it only does it when its really cold out and first started. Another thing is the rpm's dont drop off between gears. Can any one help?

[evildky]

there were some variations on the l28 injection systems, I'd take a god look at the cost start injector, maybe try disconnecting it, the problem i see is if you have a backfire into the intake that would imply you are igniting with the intake valves open, that means either the ignition timing, is way off, the cam timing is off, of you have a bent leaking or otherwise messed up intake valve

[minnesotazcar]

i was kind of thinking the cold start injector myself the revs imbetween gears might be a sticky idle air control motor (valve) i would suggest maybe picking up a can of throttle body cleaner, take the air tube of your intake and going to town theres probably alot of varnish built up in there.