Ok I have a 91 RS with a TBI 305 and my oil pressure gauge is going crazy. It was fine up until last week it just started jumping all around from 60 to 15 psi while driving or just idling. What could be the prob and how hard would it be to just put a cheap gauge from walmart on there?? The engine has 189,000 miles on it and has never had any internal problems so far.

 

sounds like a loose wire somewhere. the idle should be in the 15psi reading range and the dead head(signal when the gauge or sendign unit die) is on hte 60psi end of things. something has to be falling off somehwere. check the wires on the pressure sending unit and on the back of the gauge.

later
tim

 

dont worry, mine does the same thing .. but i never let it bother me. eventually ill get around to figure out why its doing that

 

Mine is doing the same thing, I heard from a friend that it's the cheesy sending unit, they're like $20 at autozone. Or you can even pull it out, clean it and see if that helps. Your pump runs off the distributor, so during acceleration pressure should increase but shouldn't jump dramatically up or down. I'm positive it's just the unit and not a fouled gallery or something more serious so I'll worry about it next paid vacation. If I'm not mistaken I think the unit is located next to the oil filter, but double check that.

 

Yup, mine does the same thing too. They told me it has to be the sending unit next to the filter.

 

definitely the sending unit, mine used to do that, then i replaced the sending unit, fixed.

 

Had the same problem and it was the sending unit located right next to the oil filter. Easy fix but requires the use of an extra deep socket.

 

I appreciate the help, glad it was just something simple, I will replace it this weekend.

 

hmm, i wonder if its the sending unit on mine ..

 

Mine does that when it's time for an oil change. Have you thought about that? Maybe that's your prob. Who knows.