Bobby Suth

iTrader: (2)

In short it worked fine after installed.today it went back to pegging out.Is this what happens when the sending unit gose bad?

Tuned Performance

iTrader: (92)

usually when the sending unit goes bad there is a open, a pegged out gauge the wire to the sending unit might be shorted to ground.

Maverick H1L

iTrader: (8)

You've got that backwards... That may be for every other gauge known to man, but GM gauges are backwards. They "peg out" when disconnected from their senders and read off the scale low when shorted to ground.

OP, check the wiring at the fuel tank connector under the car to make sure there isn't any corrosion or anything before you start pulling anything apart.

badjuju342

Your ground is most likely the issue , seen this before. Run a good ground to body metal and piggy back it to the black wire going into the tank , should clear it right up.

Bobby Suth

iTrader: (2)

OH,I like that Idea! why didn't I think of it?Then if that dosn't get it working I'll take the drivers seat out and follow it along the harness.It's just funny how you can have somthing working one day and the next day it's like you never worked on it.Thanks guys for all your support.You have helped me put this 86 basket case together.Do a 3.4 swap into a 90 bird and a full transplant from that dead bird into a 90 camaro.never did get the speedo working before I sold it.we gota get that one worked out.was a 305 tbi put in a 3.1 system.I'm sure it was just needing some repin coming out of ecm to gauge cluster.didnt have tac either

Bobby Suth

iTrader: (2)

check out my thinking here.My fuel pump and gauge are both grounded to the same ground wire.my pump works fine.and the gauge did for a day or two.so either the conector that connects the gauge to sending unit is not getting a good connection,the sending unit is bad,theres a bad ground on the gas gauge in the cluster.dosnt seam as connecting a jump ground would change anything.unless it's the purple gauge wire running through the interior.

Maverick H1L

iTrader: (8)

Which is why I said to start at the gas tank connector under the body and work your way forward. It's the sending unit that's disconnected from the gauge, not the ground. If you had a ground problem with the gauges, you would know as other parts of the cluster wouldn't work as well because many of them share a common ground.

Oh, and for the speedo in the 90, the Camaro originally had the TBI. It didn't run a 730 ECM. As such, there was a yellow buffer box that ran the speedo. I found that, when I did my harness swap (730 in place of 302), the speedo didn't like the signal wire coming from the ECM. You need the buffer box installed and to connect the VSS wires to it, BACKWARDS (yellow buffer to purple ECM sensor wire and the same for the other wires). IDK why, but that's the way it works. And then hook up the buffer wires accordingly, matching them with the Camaro's wiring harness.

Bobby Suth

iTrader: (2)

will do! Got it in the air now.

Maverick H1L

iTrader: (8)

First thing to do when you get the tank connector unplugged is to measure the resistance between the pink and black wires (from the tank). Should be between 0 and 90 ohms (90 ohms full and none empty). That will tell you if the sending unit is working. Then, if you have the gauge cluster removed and a long enough jumper wire, measure the resistance on the pink wire at the top cluster connector (gray or clear) and the pink wire at the tank body connector (as opposed to the connector coming from the sending unit) to find out if the wire has been damaged and is open.

Bobby Suth

iTrader: (2)

I have purple gray and black wires.gray fuel pump blk ground and purple fuel gauge.The book calls it pink too.but it's purple as it can get!so plug purple into pink and go from there.thanks mav.I'm a carpenter.How do I set my tester to get the reading?Is it the red side or black side?I got 2 cheap testers.cen-teck 7 function multi tester and sperry dm-210a. is the funny looking horseshoe the ohms side?

Maverick H1L

iTrader: (8)

The upside down horseshoe is the ohms scale. It doesn't matter which lead you connect where when you're checking resistance as it's the same either way. Anything more than 1 ohm is unacceptable in the wire itself, and if the meter gives you an error or OL reading on either the wire or the sending unit, either the wire has a problem or the sending unit does.

Bobby Suth

iTrader: (2)

ok,tested the one going into the tank and got nothing.tested another tank i got with a bad fuel pump and got a 39.thats about right for how much fuels in it.at least i know i did my test right.bad sending unit!

Maverick H1L

iTrader: (8)

... and now you get the (dis)pleasure of dropping the tank to get the sending unit replaced. Just make sure to clean all of the bolts up nice with a wire wheel and use plenty of anti seize putting them back as I'm sure you will want them to come out again without cutting anything if necessary .

Bobby Suth

iTrader: (2)

Mav,all the bolts are well lubed!I've had this tank out 10 or 12 times in the last year.pulled it and put a new pump in.put it back in only to find out the new pump didnt work.got another put it in and found the gauge not working,pulled it to make sure it wasnt hung up.back in,ground to fp come off in the tank,back out,decided to put a different tank in because ther was rust in this one.tryed different pump and sending unit only to find out was a weak pump changed to previous pump and sending unit with the clean gas tank only to find gauge worked for 2 days and pegged out again.I want to get this thing fixed and working right so I can get a new exsaust on it.tempted to use the sending unit thats sitting in my old tank.the po used some kind of foam hose to atach the pump to the assembly.But the gauge part is giving me a good reading.I GOT CLEAN BOLTS!!!thanks again mav.i've learned alot from U.I got a hatch motor issue to.

Dgill

Hey im new to the chat. I have a 89 camaro and im having the same problem no signal lights work on all four corner. No.hazard lights either. I checked all the fuses( all good) i replaced the hd12 relay. And still nothing. When i turn my lights on. All marker lights turn on but no signal lights. Nothing on the dash either when i press the signal down or up.