I bought a 96 Z28 I have replaced the fuel pump the filter the battery the plugs the plug wires the opti spark. Also replaced the crank position sensor on the bottom of the timing chain cover on the bottom of the motor I have replaced the coil and the ignition control mod. I have replaced the o ring in all the injectors as well as the small filters in the injectors. And the fuel pressure regulator on the back of the engine now the problem is this car turns over and over sometime it starts sometime it does not. it just sounds terrible it jerks and jumps. I don't know what to do next .when I bought the car it was sitting parked for about 3 or 4 years .since I don't work on it every day it seems to be worse now then when I bought it . Any help would be great


Buddy902

 

have you scanned for trouble codes? may give you something to follow. how old is the opti?

 

Hello yes I have scanned for codes none showing. I forgot to mention I also replaced all O2 sensors and one cat converter the opti is not that old I bought it new less then a year ago maybe 5 to 6 months old

 

what scanner did you use? whats the fuel pressure look like? did you lock tight the screws on the rotor, some opti's have had the rotor screws come lose letting the rotor bounce around and cause strange problems. also what brand of opti? cheap china stuff can fail in short order or not.

 

also check your plug wire routing to make sure none are damaged and that they are in the proper order. easy to cross wires and if certain wires are crossed it is hard to tell what it is.

 

Hello the opti was not a name brand but I did check it well before I installed it if I suspect the fuel pressure can i mount an inline fuel pump to see if that helps the pump in the tank is less then a year old I am going to borrow a pressure tester to compare to mine as I am getting different readings every time I check it

 

you know the harness to the opti has also been an issue that has come up often but it almost always has a code.

 

Hello I hope that harness is good it two was replaced with the opti

 

woh,,, im running outa things,,, do a good pressure test on the fuel. 4th Gen LT1 F-body Tech Articles pressure regulator may be acting up. took me 3 to get a good one, not sure why, havent heard of anyone else really having the same issue.

 

maybe test the engine temp sensor. if its showing to cold it will poor the gas to it. 4th Gen LT1 F-body Tech Articles