Foxi-Lady

Ok, just bought this 96 Z28 right? Well, of course the fuel gauge doesn't work correctly...and for some reason last night when I turned the AC on to see if it worked my oil pressure bottomed out. My fiancee'/GM Master Mechanic thinks its just the sending unit but he's not completely sure until he really looks at it. Then on top of it all I have to turn the key listen for the fuel pump at least 3 times before trying to crank it, anyone else have or had these issues?

Injuneer

1 - Fuel gauge operation/testing/repair guide:

Courtesy of Shoebox

4th Gen LT1 F-body Tech Articles


2 - Never heard of the AC operation affecting oil pressure, unless it slowed the engine down so much the pressure started to drop. Shouldn't slow the engine down - the idle air control should open up to hold the engine RPM constant. If it's the pressure sensor (top/rear of block) 0 pressure indicates a shorted circuit, max pressure reading indicates an open circuit. It's a one wire circuit, relying on the engine as a ground.

http://shbox.com/1/oil_pressure_sensor.jpg


3 - I take it the engine doesn't want to start if you simply turn the key to "start". If you have to prime the pump several times before it will start quickly, it indicates the fuel pressure is dropping off too fast, after the pump primes for the first 2 seconds, then shuts down. Put a fuel pressure gauge on the Schrader valve, observe the pressure just as the pump shuts off - should be at least 40psi. Then watch how fast pressure drops. Should drop slowly. If it drops rapidly, it indicates one of these:

-faulty check valve in the fuel pump
-leaking fuel pressure regulator
-leaking fuel injector(s)
-leaks in the lines, including the flex connector in the tank

PHXLT1

/\ what he said but im sure your soon to be husband knew this already. Good luck and congratulations.

Foxi-Lady

The Hubby lol says it's the oil pressure sending unit for the oil pressure problem. Then, he thinks the gauge is just bad on the gas gauge, because the pump was replaced a couple months ago, but he is going to look into everything else when he pulls the tranny on Wednesday. Thanks guys! This is so frustrating lol especially when the hubs is just excited to have another F-body to play with again lol.

Injuneer

A few skinned knuckles are a mandatory part of enjoying an LT1 vehicle....

If the fuel pump was changed, may be a snagged float on the sending unit, or the harness connector may be dirty.

Foxi-Lady

Few skinned knuckles for him. lol Not me. This girl isn't doing any of that lol. I'm too spoiled for that.

Foxi-Lady

Anyone remember the difference between the K-member on the Lt1 and the Ls1?

parkers Z28

Women Lol!! and a ford chic with a chevy man. poor guy ....just kidding
Do a search on here for shoebox click on the link in his signature lots of good information
in there !!

Foxi-Lady

Yeah he was a gm master tech but hasnt done it in a while and got to the point of just taking the front end off my car and removing my tranny but has forgotten a step lol, i told him its part of getting old lol