I have been trying to solve the hesitation problem below 3k. I have monitored the data ,all looks good checked the plugs and wires good. Next I decided to replace the coil w/ msd coil it ran a lil' bit better, so next I try my 30#ers lil' better a higher rpms. Then I mess with the radio ( buzzing noise) fixed. On my way home and I punch it once it hit 5000 or so rpm it back fires through the intake.

Does this sound like spark scatter in the opti because of the better coil, or a broken valve spring???

 

it does sound like a bad opti. I chased mine for about 2 years or so. replaced the opti all of my problems were fixed. opti's fail in a number of ways. cap and rotor fail, the bearing can fail, the rotor can come apart(no run condition), and opti's can have water or oil enter the housing. just to name a few...

 

ttt

 

I would look at the springs as it's RPM related.
Maybe not broken but to weak to do the job.

 

I think I will go ahead and do them reguardless (182,000 miles) I did find the ground strap and pcm groud wires weren't tighted down after replacing the coil and ICM spacer mod.
I fixed that and tried it again same problem. I did realized that the gear change (2.73 to 3.42 ) with no recalibration to the speedo may be a factor (rev limiter?).

Its weird that it happens just before it shifts into the next gear and was only a 24hour difference between original bolt-on config. vs. bolt-ons ,ICM mod, coil and 30#er's.

So the next question is ,does the trans shift by mph, rpm, or both??


thx

 

ttt