lt1 power

lately my 94 z28 has started to act up on me, i think the opti is going bad, but want to make sure. the car has been surging alot lately, the rpms will start jumping back and forth while driving. it also has a rough idle and poor performance once car gets warmed up ,sometimes it doesn't start right up like it should, almost seems like the injectors are cutting on and off. repaced injectors still surges and runs the same as before. it is a low 12 sec car and i took it to the track the other day, it ran a 13.4 @100. something is obviously wrong with the car, it is tuned, i am thinking it is either a bad opti or maybe computer related no codes or check engine light. please help what is wrong with my car??

Captainofiron

iTrader: (1)

You arent getting any codes?
to me sounds like a coil or wire problem,

Usually the opti throws a high resistance or low resistance timing reference code. If you arent getting one of those I would be cautious about throwing money at a new opti

purplefirehawk95

Another thing you might want to check is your fuel pump. Do you have a fuel pressure gauge? You should be some where around 41-47psi I beleave.

lt1 power

i checked the fuel pressure it was 41 with the key on and 38 started at idle.

ecniv

iTrader: (1)

A bad opti won't always throw a code. I do agree that it sounds like a weak coil - you can do resistance checks on the coil to give you an idea of it's health.
Courtesy of Shoebox:



You may also want to look into your ICM. Does it behave when the car is cold and get worse as it warms up?

Also, open the hood at night and look for arcing and sparking from the plug wires - you may just have a bad wire (as stated above) that's causing a random misfire.

lt1 power

plugs and wires are good and just replaced the coil car is still having the same problem.running rough surging through all rpms, lack of power. i also noticed when pulling the plugs the drivers side plugs were very lean and the pass side was stoich, what could cause one side to be getting more fuel than the other?

ecniv

iTrader: (1)

02 sensor

lt1 power

could a bad o2 sensor cause the car to surge and have a lack of power also? hopefully this is all that the cars problem is. i will check the o2 sensor and see if it's working.