Same issue, often kicks when waiting at red light and engine is hot. Then slight hesitation on acceleration. Any update on the fix please?

 

Because vehicles with the same year and model can have different features , it is very important to get as much info as possible.

Please provide info as to what was done and changed ,if it applies.
It is VERY COMMON to install parts that are defective right out of the box.
If possible before purchasing any parts ,ask where the parts were made, and save yourself a LOT of trouble..

Cheap and defective parts are sold today . We pretty much have a good idea of where they come from online parts included,

 

So far, the parts that have been replaced are the idle air control, egr, spark plugs, wires, cap, rotor, ignition coil, fuel pump, fuel pressure regulator, fuel filter and a smoke test has been performed. I try to get oem or parts not made in China but difficult. I was going to try leaving a fuel pressure guage on, and maybe try replacing the pcm. Still slight bucking at times when hot while fully stopped and in gear. Slight hesitation from full stop like out of gas feel. Runs perfect above 1000rpm.

 

A PCM from 96 and later will need to be programmed before installation is complete.

If problem goes away when throttle is increased, your vehicle either has unmeasured air coming into engine. (vacuum leak or leak between engine and throttle body) or possible intake gasket/bolt washer seal problem.

When removed the intake gaskets can look good but STILL leak..

 

good morning and thank you for your suggestion. I sprayed starter fluid in the area already to see if that was the case and noticed no idle change. Also cleaned the throttle body already. I will have the pcm programmed first if I try a new pcm.

 

Is there any way you can post the data stream info which would include the fuel trim and oxygen sensor info ?

Should be able to verify suspicions with that info..

 

yes, I did sets of 3 screens starting cold in n. Then in D. Then in n higher rpm. Then back in d. Finally I found a fuel flow setting. Noticed it sometimes jumps to 0 for 1 second when I quickly tap on the gas.

Cold n

Cold n

Cold n

Cold d

Cold d

Cold d

Cold n higher rpm

Cold n higher rpm

Cold n higher rpm

Warm d inital tap of throttle. Fuel flow shows 0 at times for 1 second

Warm d

Warm d

Warm d

 

Today I tried new sensor settings. I'm noticing rapidly fluctuating voltages on both 02 sensors while warm from .1 to .7v constantly. Is this normal? Also the live data pict showing first higher rpm, then idle, then in d.

 

Talk about information overload,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Many things caught my eye , that Vref should be 5 volts. Something is pulling that down. One way to find that cause requires removing plugs from the various sensors and watch which sensor is shorted pulling that voltage down.

 

You can try one other thing to verify if the intake gaskets are leaking air.

Shoot a little propane or starting fluid into the oil fill hole. If the idle stabilizes., you verified the intake gaskets are leaking air.