Gauge Issues

[Honest_Bob]

I bought a set of Maddad gauges a while ago. Boost, Oil Pres, EGT. I've had the boost working for some months now and finnaly got some money to get the egt and oil pressure sensors installed.

I'll start off with the EGT. My origonal EGT gauge didnt work from the start, the awesome guys at Area 1320 installed the probe in the exhaust manifold for me. They tried to test the gauge with a blow torch and it didnt register as anything and it didnt work while in the car either. Got another gauge under warrenty from Rich at Maddad. Disconnected the battery and plugged in the new gauge (leaving the old probe in place.) it works! 1.5 days later it craps out again, I test the probe with a multimeter and its putting out 15mV and it gets higher as I rev and hold the rpms. To me that says the probe is working and has to be the gauge, but why did it work for 1.5 days and crap out. The old gauge is being sent back to Maddad for inspection and Rich is gonna get back to me as to what went wrong.

I checked every wire dealing with the gauges on saturday, I swapped the egt gauge with the new one I was sent and it sends out the same voltages. I didnt find any kinks or cuts in the old probe wire.


Oil Pressure
Area 1320 installs the oil pressure sender using a sandwich adaptor (mmm sammich) and it works for 2 days. I thought she was totaly dead but I found out its flakey. It seems to work properly when the car is stone cold. It'll stay at 90psi or so until it warms up. After its warmed up it shows I have no oil pressure until the engine is reved above 3k rpms, then it shoots up to 100. When I let off the gas it goes down to 80 and holds (as I think it should) then drops to 60 holds a second and goes back to 0. I'm guessing maybe a bad ground? but why would it work for 2 days and then have grounding issues?

I'm at a total loss. Any input would be apreciated.