my 94 Z runs fine cold, when good and warm, only around 2500 or so rpms it feels like it's losing spark, if you put more gas to it then it runs fine, but when you're cruising with it it does this?

mainly when the cruise is on i notice it, but i think that's because it's at a constant rpm/speed.

if you're shifting often and never at the same rpm long you never even notice it, but it started a couple of weeks ago.

i put a new TPS on there that i had from my last car and still no change, personally it feels like an OPTI or an ignition module, i have an extra module, and i'll probably swap it out tonight after work.

any help is much appreciated.

where is a good place to buy an opti if the need were to arise?

 

Im tryin to figure out the exact same problem. Somebody told me it was the coil. But im figuring its in the fuel intake somewhere, Pump or injectors etc.

 

02 sensors ? try unplugging them and take it for a ride and if it rides better without them youll know they are the problem. just dont leave them unpluged youll get like 5 mpg

 

im havin the same problem, only miss under load at about 1500 to 2500 rpms other that that it runs amazing, i cant figure it out, been messing with it for months

 

i figured some of the veteran LT1 guys would have chimed in by now....

 

I recently fixed my low rpm stumble hestitation (it was bad) by replacing the Bosch Platinum 4+ plugs with NGK platinums. The Boschs only had 1,000 miles on them......

 

ihad the same problem at low rpms when i punched it it would run fine turned out i had small head gasket leak the way to check this look at the coolant reserve dip stick mine had a grey clay like substance(carbon)all over it .I retorqed problem went away

 

I would check the plugs, wires and coil for starters. Wouldn't hurt to check the fuel pressure as well.