Well just recently i got my 94 z28 running again after several months of downtime due to a crappy MSD opti. So its back running now and it seems like it has lost some of its power. A couple of questions:

1) How much is a low coolant light hurting me?

2) I switched the PCMs while in the process of eliminating things that was wrong with the car...is it possible the other PCM had a tune and now i got a stock tune?

Answers/suggestions are appreciated!!!

 

Is the coolant level low? If so, I would address that issue although I don't think it would be solely responsible for the power loss. Its possible your other PCM was tuned, but you wouldn't know unless you swapped them around again or had a tuner hook it up and look at it. I would check over some simple things to, pull the plugs and make sure they are in good shape. If you have stock Delco plats, it is pretty common for the pucks to fall off creating a very large gap which can really degrade performance. It wouldn't hurt to check the wires also and put a fuel pressure gauge on it.

 

Well plugs are NGK TR-55 GPs which are pretty new, has a new fuel pump with a pressure of around 42-43 at idle. But im positive the coolant level is right, the water level is right in the overflow tank...the thing is sometimes the light comes on and other times it doesnt, could the sensor be bad???

 

The sensor can get gummed up or the connection could be loose or dirty triggering a false dash light.

 

Will that hurt performance any tho?

 

No, that input is independent of the PCM and only goes straight to the dash.

 

mine does the same thing, the low radiator or whatever light will randomly come on and off along with the ses light, they dont come on/ off at the same time most of the time though. where is the low coolant level sensor cause i will take a look at mine

 

Its in the drivers side head.

 

nvm i found it on shoebox's site

 

Well it just puzzles me tho. I guess a tune can make big difference. The power loss seems more up top then in the bottom rpms....its just not what it used to be

 

im going through the same thing right now... figure anything out yet?