91 Chevy Tracker runs good cold

[gj68]

I have a 91 Chevy Tracker 4WD. It has a 1.6L with a 5 speed trans. It runs good when it is cold but when it warms up it is hard to maintain a steady speed without it bucking like a horse. If you are going faster than you want and let off the accellerator it slows down very fast and then if you step on the gas again it throws you back in the seat. It doesn't do it until the temp starts to rise. Any Ideas would be appreciated.

[jtgh]

sell me your car, I just got to have a Kick that throws me back in my seat , heheheheh

This must be an 8 valve , TBI , kick. (runs off a map sensor, not a MAF)

first off, did you try tuning up the car?
cap,rotor, wire, plugs, and all filters? (every 50k if you want to save gas, or money)

does car start at 1200 rpm then after 5 min. it drops quickly to 800 rpm.
this is the moment the car tries to enter close loop.

still would like to know what engine you have. tell us that first.



good day, happy holidays

[gj68]

Originally Posted by jtgh

sell me your car, I just got to have a Kick that throws me back in my seat , heheheheh

This must be an 8 valve , TBI , kick. (runs off a map sensor, not a MAF)

first off, did you try tuning up the car?
cap,rotor, wire, plugs, and all filters? (every 50k if you want to save gas, or money)

does car start at 1200 rpm then after 5 min. it drops quickly to 800 rpm.
this is the moment the car tries to enter close loop.

still would like to know what engine you have. tell us that first.



good day, happy holidays

I think it is an 8v (I see nothing that says that it is 16)with EFI. I have changed the spark plugs and wires only. It does idle fast when cold then drops to about 700-800 rpm when it warms up

[jtgh]

if car bucks real hard, then that is caused by spark. (bad ignition)
spark loves to fail when cylinder pressure are high.
accel, hills, passing, lugging, etc.
tune up is only way to prove it is not. ( or shop with sunpro ignition analyser scope )



bogging is a condition that feels like car is pulling a Winnebego.
some call it a huge long flat spot.

good news ,car is trying or is entering closed loop. Cheers.
it is trying its best to get the OXY sensor , to swing at 14.7 :1 air /Fuel ratio.
with this happening you can get up to 30 mpg on a 2 door.

ymmv.
it could be a bad igntion switch , a bad ECU , bad wiring , a marginal CAS sender, bad coil , bad ignitor but all those things
cost 2 to three times the cost of a tune up.

[gj68]

Thanks for the speedy reply. I will try the tune up first and hope that fixes the problem.