digital gauges crazy
 

i have a 96 corvette lt4 with a new update to 396 stroker

now i have a problem.

When i start the car, all is perfect, but when the water temperautre arrive to 194º in 20 minuts of normal function, the digital temperature becomes crazy( low, 2º,10º, 40º, low) but the analogic gaugesmeasures 194º (the correct measure). then the car stop and start engine again(with false measure of water temperature)
The car is drowned, and several times I stepped on the accelerator to achieve star engine.
[/align](sometimes the digital speed , flashingless than a seconda false speed numbers, example: 134miles when the car really run at 10 or 20 miles for hour).
[/align]
[/align]I,m crazy, please give some idea.
[/align]
[/align]thanks
[/align]

RE: digital gauges crazy
 

I don't have a '96, but let's start with some easy stuff.

Do the digital and analog gauges have separate temperature sending units? Check and/or replace the sending unit for the digital gauge.

The gauges only report what they are told, but the circuit needs a good clean ground to operate properly. Check the grounds on your system. Also make sure that your temperature sending wire is not up against a heat source (exhaust manifolds)or a source of electromagnetism, like the alternator. Heat creates resistance in an electrical circuit. Electrical wires can pick up stray voltage signals from other sources, like an alternator or some other moving piece of metal or even from spark plug wires. You may want to try shielding the suspect wire(s) from external voltage sources.
Finally, check the ground on the computer itself. We had a cadillac that had similar problems and it turned out the ground for the computer was bad.

I hope that helps, and keep us posted on your progress!

[sm=icon_cheers.gif]

RE: digital gauges crazy
 

I think your 96 works like my 92 LT1. If that is correct, the 2 wire sender on the water pump feeds the ECM and the digital readout, so if this is not accurate the ECM does not know what the engine temperature really is. The analog guage reads off a sending unit on the right cylinder head, this sender only feeds the gauge. It sounds like the sender on the water pump has failed, and reads incorrectly after it gets warmed up.