SStriker

iTrader: (3)

Looking for some solutions/ideas.
The car is a 94 Z28 Fresh build Forged 355 with a small 224 cam, stock ported heads/intake. Tranny is a stock rebuild with a 3500 converter. MSD 8.5 wires with BR7EF plugs, Mids and all the emissions stuff removed and tuned out. Motor is built for the nitrous.
Here is my problem:
I still need to install the nitrous so the problem is all motor. At WOT the light comes on around 90mph and the car feels like it looses 100hp. From 0-70 it seems to pull hard (normal) and as long as I don't trigger the light I can go from 0-70 or 80 all day long. Almost feels like its pulling timing from knock/noise. I still have LT1 knock module. I was told that the light would not come on from knock or pulling time.??
I am not sure if it maybe the plugs or misfire or bad o2. Oh forgot to mention that light goes away after I let of the gas. So wondering if someone has had similar issues or if there is a way to check codes even after t light goes away. Its hard to find someone with a OBD1 reader.
Any help/ideas is appreciated.

Penz

iTrader: (1)

From some of the symptoms listed, it sounds like it may be throwing a code for a faulty TPS. Do you have a aftermarket throttlebody?
The reason I bring up the TPS is because I had a similar issue with my car, except for the power loss. Anytime during a pull in 3rd or 4th gear, the SES would come on due to the TPS voltage going over 4.91v for longer then 3 seconds.
However, if the TPS is malfunctioning, it could be causing the computer to not read 100% throttle which could explain the power loss. I would swap out the TPS to see if it makes a difference as it is something very easy to do.

SStriker

iTrader: (3)

Its worth a shot. I have one sitting in my garage. And it does have a bbk after market TB. So its possible.

SStriker

iTrader: (3)

Bump for any other thoughts. I will be swapping the tps sensor after work today to see if that works.

chevymec

iTrader: (19)

Do a search and you can find how to manually pull the codes.

transbird95

iTrader: (4)

no one can tell you for sure, you will have to pull the codes or flash them with a jumper wire. Does your converter lock at at wot?

SStriker

iTrader: (3)

I did a search for pulling codes w/out a scanner and 94 u need a scanner. 93 was the last yr for doing it with a wire. How can I tell if the converter is locking under WOT?

roach4047

Any auto parts stores around able to pull codes for you?
They do around my area but my stuff is OBDII. Not sure about any of the LT1 stuff.

SStriker

iTrader: (3)

Obd2 I can find anywhere. But obd1 is a little harder.

SStriker

iTrader: (3)

Update: So, found a guy that had OBD1 reader. Now to find out if the car ECM stores codes. It Does. The only code it was showing was TPS sensor. Everything else looked good at idle and the LT1 knock module is Not detecting knock/noise. So I'm not going to buy a LT4 module (for now). I replaced the TPS and everything seems to be working as it should now.