Wasted time on fuel pressure - Third Generation F-Body Message Boards

Formula_Wolf · 06-26-2009, 12:31 PM

This is kind of funny. I'm doing alot of engine work and get to the card tuning step. Btw this car has been sitting for 2 years in storage. I got to Start her up and cicle the parking lot once the let it warm up before I start messing with the idle and a/F mixture screw. I thought something went wrong with the demon 625 till I noticed could no longer see gas in the primary sights or clear fuel filter. Checked the lines for kinks front and back but there were none. The fuel pump is dome new 40 dollar cheapo from the pep boys isle' it's rated at 9 psi though. It looks good and I feel vibration in the rubber hose. So drop by drop the primary fuel bowl fills up with enough gas so I can pull back in the garage. I jacked up the rear end and checked the huge silver fuel filter and it looked clean but was somewhat hard to blow air through. Had to take it off with the tail end of the hard line to avoid stripping the line nut. I lead a hose to from the pump to a coke bottle and got nothing but air! Knocked on the tank and it sounded a bit hollow. So... I might have wastes 2 hrs because I'm out of gas! LOL funny that the guage is pegged at full. I'm not 100% sure but I think I might just have a wiring issue. If anyone has any time saving tips to avoid wasting time let me know. Lol no gas... Come ooon what are the odds.

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Formula_Wolf · 06-26-2009, 01:22 PM

Oh nice... I just remembered that when I was working on this car two years ago I replaced the fuel pump cause the original tpi pump of course put out to much gas. I had a holly carb that handled the high pressure like a champ for several years, odd. The new Demon just floods and gets all jacked up. Anyway I cut the three wires not knowing what the pink wire was. Apparently thats the fuel sender wire lol.. which if cut.. will make your guage read a full tank! Mystery Solved! This car forces me to learn a great deal of knowledge while I just try to keep it running. I give thanks to this old post. Thanks Rottery and Ron! I'm just remembering where I was at 2 years ago on this project.

http://www.thirdgen.org/techboard/te...esnt-work.html (gas gauge doesnt work)

Here's a reply of a post a year ago that deals with some checks on the sender wire...and if memory serves, the sender wire is pink...
To check the tank sender you would need to drop an ohms test at the tank, on the sender wire. I think the connector is on the driver side next to the tank. Ground your ohm's meter to the tank, and the other to the pink? wire at that disconnected connector...

Ron
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4/02

The gauge should have (3) connectors. One positive, one negitive, one sender.
After you've checked that the pos. & neg, are present you'll need to verify that the sender wire from the tank float to the gauge is not compermized.

Does the gauge peg beyond full ? If it does then you have an open, since the gauge only reads between 0 (Empty) - 90 (Full) ohms. If you have an open circiut the ohms would be greater then 90 there by pegging the gauge.

If its stuck on empty, then check the pos & neg wires, disconnect the sender wire, does it do like mentioned above ? If nothing can get it to move, you may have sent 12 volts down the sender wire by accident, which = gauge death.

Ron

ronterry · 07-06-2009, 01:50 PM

Glad I could help FW. Thank God I made a note book from back then, cause I haven't worked on 82 in years ~ though I try to fire it up every year. Hurt my back in the late nineties, and up until recently I had surgery, but it's permanently shot. I can lift more than 25#, but my back will not and this puts a real kink in everyday wrenching.
Today I'm a gun nut! Yeap gunsmithing/machinist works for me and my back

I also run into EDE all the time, and I don't know what it is but he's also a gun nut? So when you guys kill your back, we'll see you on the gun forums

I do remember that wiring on the drivers side, and yeap I remember that pink wire

On the 82 I replaced the stock fuel cell with a 22g foam filled setup, but I kept the fuel gauge, all though I replaced it with a Autometer setup. Also went with a manual Holley pump, but I don't recall ever getting the Holley tuned real good. Wide band air/fuel kits where kind of new to the scene, so we just read the manifold temps & narrow band O2 sensors to get us close.
Anyways, thanks for the walk down memory lane....

BTW: I'm learning how to rebuild these 4L60E's, so I can fix my little Vette. So I haven't given up on wrenching, but use it to save about fifty million bucks! Who's got three grand to blow right now

plus I have all summer to get it done.