Car has all the symptoms of the opti going out, hard start, poor throttle response, down on power, but no SES light. New fuel pump, new FPR, good pressure all around, new coil and ICM; sometimes it will fire right up, other times it won't start at all. Checked the connections, had one frayed wire that was taken care of; don't want to deal with another opti change if I don't have to.

 

No it won't. I've replaced more opti's that never set an ses light or code than what I have ones that did. Good luck.

 

check the Engine coolant temp sensor. It's in the water pump

 

The ECT sensor can be a problem but it really controls fuel tables.. if its real cold the car will add fuel and if its warm take away ( things like that) but have nothing to do with throttle and power that much.

 

Ive had several bad optis and not one of them through a code....for what its worth

 

no, not always
i opened one up on a firends '94 z last week that never once threw a code and was a total bitch to tune.
1. the rotor was 1 plastic rivet from being sent into oblivion (litterally wobbled around)
2. the cap electrodes were worn almost completely down
3. rust all over the inside
optical encoder-wise, there was not enough of a "miss" detected on the high and low pulses to fire of the SES light but the failing water pump bearing we discovered would have guaranteed one had we not addressed it when we did.

 

I had no codes with my first opti failure, just down on a ton of power, lots of backfiring, wouldn't accelerate smoothly or rev past 3k or so.

 

Thank you for the information gentlemen.