VegasRomeo

My 1995 Z28 Camaro is misfiring and shaking. Was told it was the o2 sensors so replaced them and still having the problem. The car will also hesitation while accelerating or shaking during engine idle. Could this possibly be a bad crank position sensor or throttle position sensor? the car also turns over for awhile before starting. Can anyone please help. Just got the car and don't know all that knowledgeable. Thanks

Joe Bellman

I would start off by checking the plugs, wires and opti..

Injuneer

Have you scanned it for codes? Have you checked the fuel pressure? Scanning the 95 is a problem, because it has an OBD-I PCM and an OBD-II style 16-pin ALDL connector. You have to use an OBD-I scanner, with an adapter plug, or use jumper wires from the 12-pin OBD-I scanner cable to the 16-pin ALDL connector.

It's not the crank position sensor because it doesn't have one. They added a CKP sensor in 96 as part of the OBD-II changeover, but it's only to detect misfires. Does not control the engine in any way.

It does have an optical cam position sensor that is part of the Optispark distributor. But a problem with the cam position sensor will set a code.

VegasRomeo

when it was checked out they said they ran engine scan- no codes, pressure test- passed, engine block test and pressure block test - both passed. was told one o2 sensor needed replaced and engine was leaning out the right side. They said this was causing the problem but replaced both o2 sensors and still is the same.
Today I called a friend and told him what it was doing and right away he said that the Opti spark needs to be replaced and the water pump should be done at the same time This is costing me more and more money and just want it finally fixed.
What are your thoughts on thinking its the opti spark that needs to be replaced?

shoebox

If it has not had a tune up in a while, I would start with plugs and wires. I would not consider the opti before that.

DoctorPopcorn

I recently just had similar symptoms on my '97 V6 Firebird (recently sold). One day after work I walked out and put it in reverse and it started shaking violently, acting like it wanted to kill (never did), and there was great power loss and hesitation. I had no idea what it could be, scanned it and read a cylinder 5 misfire. Took it to my godfather and turns out it was the cylinder 5 coil pack. $50 fix and ran perfect again after that. Just another thing to check

omega552003

LT1s only had one coil for all cylinders. It does sound like an
optispark.

DoctorPopcorn

This just shows how much more time I should be fraternizing with my new LT1

VegasRomeo

thanks for all your suggestions. Had a mechanic come look at it for some reason the car isnt throwing up any codes even when he disconnected stuff that should of turned check engine light on. But he told me to take it in to the dealership and get a full car scan to find out exactly everything that is bad before he replaces anything that might not even be the problem.