My oil guage is shot and is all the way to the top so Im guessing the oil pressure sending unit is shot. Where exactly is it located and what does it look like? Is it pretty easy to replace? Thanks.

 

In most of the later 3rd gens, it was in the drivers side of the block above the oil filter. If you are working on the 1984, it should be located at the rear of the intake manifold (almost under the distributor) in a notch in the rear of the manifold and either screwed into the block or screwed into an adaptor that is screwed into the block in the same place. The adaptor (if present) will allow the oil sender to mount at a 90 degree angle to the block (pointed at one of the fenders, horizontally).

On the 1987 305 car I rebuilt, it was under the distributor, on my 1989, it was above the oil filter in the side of the block. Good luck!

I hope this helps.

 

As a side note, if it is all the way to one side, the connection may have come loose. Most bad senders I've seen (I worked at an autoparts store for many years) will leak (and possibly still work, but leak oil). I can't remember if high or low resistance is a high reading, if it is high resistance=high oil pressure (and I think it is), then a loose wire will peg the gauge.

Just a thought.

 

Thanks for the detailed instructions bro!

 

No problem and good luck!

 

when my sending unit went out, it started reading low and was very sporadic. i'd double check the connection before buying a new one.

 

My 88' IROC-Z has the Oil Gauge sending unit (single wire) on the driver's side of the distributor. It also has an Oil Pressure Switch (two wire) just above the oil filter to disable the the Fuel Pump to protect the engine if oil pressure is lost, and to kill the eninge if there's not enough oil pressure after the startup fuel pump relay times out.

 

My 88' IROC-Z has the Oil Gauge sending unit (single wire) on the driver's side of the distributor. It also has an Oil Pressure Switch (two wire) just above the oil filter to disable the the Fuel Pump to protect the engine if oil pressure is lost, and to kill the engine if there's not enough oil pressure after the startup fuel pump relay times out.

 

say it is the sending unit, then how much does that usually run $$$ ?

 

i know the acdelco replacements are 60$. i don't know about a cheap a$$ auto zone replacement.

 

You're actually backwards on the use of that switch.

When you turn the key, the pump runs for 2 seconds to make pressure. Then, when you start the car, it closes the relay and runs constantly.

The switch is an oil pressure switch. It is there as a backup (to avoid getting stranded with a dead fuel pump relay). If the fuel pump relay fails, the car won't start. So, GM added a switch that is closed after the motor is cranked long enough to build oil pressure. Once you crank for a few seconds and the oil pressure builds and closes the switch, the pump runs and the car starts.

If you have a 3rd gen that has to be cranked for 5-30 seconds to get it started (a bad fuel pump relay), it is almost always this condition (replace the fuel pump relay).

Hope that helps.

 

not quite, the fuel pump relay is only energized for the 2 sec. prime, after that, the oil pressure switch is the only sorce of power to the fuel pump, try unpluging your oil pressure switch and starting your car, it will run for a sec off the prime, then it will die

 

Hmm....Oddly enough, this information came right from the factory service manual for a 1988 Camaro....

 

http://experts.about.com/q/808/3274619.htm

This is for a Chevy van, but it is the same system....