95zguy

So im driving down the road and my car starts acting like its running out of gas,which was not the case. its a 95 z28 auto all factory minus cai and deleted emissions hvac,cat, smog punp, a/c, and tbb. so now when i give it a little gas it misses, stunbles, cuts out, give it a little more gas and it back fires bad. it does it in every gear. its got 118000 on it but only 18000 on the rebuild. dosent do it as bad when its cold or if i start out in low gear and run it up to 3 or 4000 rpms and manually shift it. ive checked and cleaned the maf, both o2s all fuses injectors and ive changed the fuel filter plugs coolant temp sensor and air filter. had fuel pressure checked the guy said it was pumping 45 lbs at idle with the vac line off the reg. 2 weeks like this and i havent got an ses light. i was thinking opti but shouldnt i get a light if that was it? all help would be app. thanks

Anthony Williams

iTrader: (3)

Opti Spark is going bad.

Formula.Fx

Opti. Good luck.

95zguy

Thats what i was thinking but shouldnt i be tripping the ses light with it missing that bad? Also the car is running way rich when i first start it puffs out black smoke and i can smell it when its idling.

wrd1972

iTrader: (12)

Before we throw the opti under the bus, check the plug wires and plugs. If the wires are old, worn or cheap, they can cause misfires. Get a multimeter and to a continuity check through the wire and look for high resistance. I recently had an issue with this and repaired the wires and fixed my misfires. Ensure the plugs look good too and are not excessively gapped.

All that fails, your down to the opti cap being the likely culprit.