I recently bought a beautiful '89 IROC-Z 350/5spd. One of the problems that I have is bouncy gauges, particularly the fuel gauge. The other is that the coolant temp gauge doesn't work at all. I haven't had/taken the time to really look into it, but is this a common problem? What most commonly goes bad, the sending unit/sensor or the gauge? Basically, where should I start looking to minimize the time I take looking? I have 2 kids and pregnant wife that can't have me tinkering for too long.

 

Was the 350 or 5 speed swapped in?

 

Lol. Just bought an 89 with 2 kids and prego wife... doesn't want to tinker??? LMFAO good luck dude. These things take LOTS of tinkering!

And congrats. We just had our second boy 4 weeks ago!

 

Between the '89 that I have now, the '85 and '91 that I had before all had gauges that were 'bouncy'.

 

The 5spd was swapped in. My wife is fine with me working on the car, just not for extended periods anymore. Most stuff will have to wait until her and the kids are in Europe or something and I can have the van and the Camaros. Wasn't hoping to hear that bouncy gauges are normal. Would Autometer gauges or the like help?

jrhaus, Congratulations! Kids are awesome! Except when they're not.....stupid little cockblockers.

 

LMAO!!! Yes, they are great... sometimes!

 

A quality aftermarket gauge can help, or you can send in your original cluster to get re-calibrated. I wouldn't do either without ensuring that the harness is in good condition or replaced with a new one. New gauges with original wiring, still inaccurate gauges. I may be wrong, but I believe that they 'bounce' because they don't have a buffer (like for the fuel level, I don't believe there are baffles in the tank so the fuel sloshes around). I could be wrong, but that's my interpretation.

 

The fuel gauge will bounce around due to that there isn't a slosh module to prevent this like there is in newer cars. The sending unit is wired straight to the gauge with nothing to prevent the gauge from bouncing as far as I know. My iroc does this also. I can estimate how much fuel is left just by how far the gauge bounces. Don't know if there is baffles in the tank(haven't seen the inside of mine) but I don't think these would help much if there is as the level will go up and down as the fuel sloshes around. Your temp gauge not working might be the sending unit is just unhooked. Check the wire at the sending unit on the driver side head in between the #1 and #3 spark plugs.

 

Take off the gauge cluster completely and look at the printed circuit board. If it has corrosion on the back and/or damage, replacing it should solve all your problems. It did for me and was only about 80 bucks shipped. While it's out, you can also polish up the lens and upgrade to LED lights as well.

 

check grounds

 

I suggest just taking the cluster off and cleaning all the contacts. Helped my gauges out a lot.

 

Get someone to make a baffle around the sending unit in the tank so sloshing doesnt make the gauge bounce as much.