92 Camaro RS with 5.0 TBI

I think it may be just a ground wire loose somewhere, but I wanted to ask around first. I have know idea where to start...

I took my car into the shop last week to have it tuned up. It hadn't been run in 3 years. It wouldn't crank because the gas in it was dead, so they pulled the fuel pump relay switch and straight wired it to pump out all of the dead gas so they could clean the tank, condition it, and fill it back up. They also did some other work: checked the timing, greased distributor, replaced motor mount/struts/ball joints/rotors/brakess/park plugs/water pump, and lubed the rear end.

I had got the car to crank a few days earlier, before taking it in to the shop, and the guages were working fine at that time, so I am not sure if it is something that they did while working on the car or if it just went bad.

Now, the fuel guage just jumps around. When I crank, it sits about 1/4 tank above the full mark. When I go down the road it will just jump back and forth at random points. It seems to move down more when I hit the brake and up when I hit the gas.

Also, the oil pressure guage is running a bit high at idle and seem to move back and forth more than it should. It just shakes instead of holding steady.

Also, I drove the car for about 30 mins and the temperature guage never left 100, so I bought a thermostat and gasket to change it. Not sure if it is related, but figured might as well replace it now.

Any ideas as to what would be causing this or has anyone else had this problem before?

Update: I checked the ground on the battery and it seems to have a good connection.

 

i have the same problem with my 91 z28.. everytime im accelerating the fuel gauge goes up and then when i press the brake it goes down

 

best way to fix the gas gauge in a 80's/early 90's chevy is to sell it and buy a new car

 

same problem here too, the faster i go the more fuel i have, lol. I havent even began to search TGO yet for info, I am sure it is here fomewhere though.

 

floater technology

 

Quote:

Originally Posted by georgia_boy

I think it may be just a ground wire loose somewhere……………………I checked the ground on the battery and it seems to have a good connection.

Due to the fact more than one gage is erratic it might be a bad ground in the dash so check those first.

If all the grounds are good you can monitor the oil sender with an ohmmeter.

Drive the car consistent with what was causing the problem to see if it persists.

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Happy Racing!

 

Thanks for the responses. I will look into the grounds on the back of the gauge. I figured I would have to take the dash pad off to get to them, but since the car has set for 3 years, the dash pad is in about 3-4 pieces...so I am trying to leave it alone until I can get a replacement.

I finally got a chance to drive the car today, and it seem to be a little different. I filled the tank up to make sure that it should read completely full, but when I first cranked it the hand went all the way to the right (1/4 past Full mark). I turned it off and turned it back on and it seemed to be right. I drove about 20 miles to work on the highway and the Fuel Guage and Oil Pressure seemed to work fine. The temperature never left 100, so I will change the thermostat tonight.

However, when I got off the exit to go to work and took a sharp turn, the gauge went back to 1/4 over Full. I took another turn and it it went back to just under full, which is where I estimate it should be?

Not real sure unless the floater in the tank is messed up?

Even when I turn the car off, the hand doesn't always to back to the left. Sometimes it just sits all the way to the right.

Note: The Oil pressure gauge only shakes now when it is at an idle, which may be just the car's movement.

Any more suggestions?

 

Quote:

Originally Posted by georgia_boy

the floater in the tank is messed up?

To find out disconnect the sender wire and connect a low cost (the type that just uses a small 1.5 volt internal battery) ohmmeter to the sender wire and ground.

Use the 100Ω scale or closest to it.

Now, while driving you can observe the meter.

If it jumps inconsistently you know you have a bad sender or wires going to it.

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Happy Racing!

 

This is because with these old cars there is no buffer. in new cars the car accounts for the movement around corners and hitting the brake and so it doesn't react to that. In these old cars, when you hit the brake the fuel goes to the front of the tank, the floater drops down, and the guage goes down. then when you accelerate, the fuel goes to the back of the tank, the floater rises up, and the guage goes back up. Thats just the way old cars are. but in the case of the Original posters problem, i would say its more than that simple explination, something is definately goin on there.