Well just bought a 87 Iroc. 305tpi to 350tpi swap. In pretty decent shape needs some help in some areas though. First Tachometer is off, by about 500 down low 1500 up high. Spedo Is off by about 5-15mph. Fuel gauge doesnt work. Oil pressure gauge doesnt work. Needs tires and struts. Anyone help with the fuel or tach problems would be awesome. Oil pressure, I'm sure is the sending unit. Easy enough, spedo Probably put the wrong gears in when trans was rebuilt. Also I have a plug chillin by the mirror (sticking out of overhead console) any ideas what that might be?

 

Wonder if it was actually originally a 2.8......

 

Was originally a 5.0 Is now 5.7. Seems tp have 5.0 tune still

 

Anyone got anything to say about the Tach. Id really like to get that fixed.

 

I just fixed the tach on my 90. But their boards are set up different than 87s.

First thing to look at is .... since you have multiple gauges issues ..

Is the gauge cluster plugged into the contacts correctly ? Pull cluster and check the
circuit board contacts where it plugs into the receptacles. Since you are having multiple problems, tells me that maybe off. Happened to me when I reassembled after my tach repair, the circuit board sort of folded when reinserting. Pulled back out and applied some tape to stabilize it while plugging back in.

 

well I just talked to P/O a bit and says the spedo is off cause the rear end gearing is different. The oil pressure gauge seems to be the sender. The fuel and tach I guess will wait till my LED's get in. Ordered a bunch to do the dash with, Ill check the plugs/contacts when replacing the bulbs. Thanks.

 

Well had the dash out. Didnt find anything obvious.

 

The fuel gauge issue could be a bad fuel level sending unit (in the gas tank).