Fuel gage acting up. - ZR-1 Net Registry Forums

Z51JEFF · 11-15-2013

Ive got to get my car smogged here pretty soon so Im starting my pre smog workout.As instructed I put a bottle of CRC 05063 fuel cleaner in a full tank of gas and now the gas gage doesnt seem to be working right,wont move below 3/4 tank.I dont drive the car much,maybe twice a month around town.Is my sending unit dying?

GOLDCYLON · 11-15-2013

Common C4 problem. Make sure you set your trip odometer

mike100 · 11-15-2013

Quote:

Originally Posted by GOLDCYLON

Common C4 problem. Make sure you set your trip odometer

I have been asked to help someone diagnose the same exact issue. So is it a dead sender, or a sticky mechanism that can be worked with and cleaned.

GOLDCYLON · 11-15-2013

Quote:

Originally Posted by mike100

I have been asked to help someone diagnose the same exact issue. So is it a dead sender, or a sticky mechanism that can be worked with and cleaned.

Normally its a combination. The unit tends to hang when when the car is not driven and tends to seize into the postion. Many C4 owners have been stranded that simply have run out of fuel on a "FULL" tank. By then the fuel pumps (remember we have two) are normally fried as well. I always suggest you set your trip odometer on your car for this reason. If you all of a sudden start getting pnenominal Gas mileage you will know something is up. It's a well documented C4ism dont forget fellers just like their owners these cars are getting long in the tooth.

msmoore · 11-15-2013

I recently had the same problem and found a thread on CF that was very helpful. Search for "Fuel Gauge Sending Unit Repair Tech Article" by Frizlefrak in the C4 section. It has instructions and even photos of exactly how to fix it. The only difference is that we have 2 pumps. It was a bit tricky to get the assembly out but with a little patience, it will come out.
I went step by step and it worked like a charm. I still reset the trip-odometer but the gauge is working fine now.

ZR1North · 11-17-2013

Quote:

Originally Posted by Z51JEFF

Ive got to get my car smogged here pretty soon so Im starting my pre smog workout.As instructed I put a bottle of CRC 05063 fuel cleaner in a full tank of gas and now the gas gage doesnt seem to be working right,wont move below 3/4 tank.I dont drive the car much,maybe twice a month around town.Is my sending unit dying?

Had the same issue with mine, Jeff, albeit after I hit a curb. Problem was with the metering assy in the tank; it was hung up on the mounting bracket as others have noted can happen. Easy fix once you get it out of the tank.

Z51JEFF · 11-17-2013

O.K. heres the deal,Im loosing my mind our Im just plain stupid.As stated I put a full tank of gas in the car with some system cleaner before I get the car smogged.I drive my car a few times a month or whenever I get the itch but Ive been driving abit more to run this tank of gas out.It had been a week since I last drove the car but I knew this tank of gas was just about out but noticed the gage was at 3/4 a tank but had 190 miles on the ODO,I always reset the ODO with a tank of gas.I figure this tank is low at 190 so I go fill the tank and it only takes 5 gallons,5 gallons out of a full tank would be about 3/4 full.Sooooooooooooo,at some point I filled the tank with fresh gas and forgot to reset the ODO,and I dont remember doing it.At least thats all I can think of as to what might have been the problem.

csavaglio · 11-17-2013

You're not going crazy.....it's all in your head.....

I've done that before. I've noticed my ZR1 stays "full" for about 100 miles, then starts dropping rapidly. The '96s I have/had would stay on full for only about 60 miles before dropping, but not as rapidly as the ZR1s gauge shows.

msmoore · 11-18-2013

Quote:

Originally Posted by msmoore

I recently had the same problem and found a thread on CF that was very helpful. Search for "Fuel Gauge Sending Unit Repair Tech Article" by Frizlefrak in the C4 section. It has instructions and even photos of exactly how to fix it. The only difference is that we have 2 pumps. It was a bit tricky to get the assembly out but with a little patience, it will come out.
I went step by step and it worked like a charm. I still reset the trip-odometer but the gauge is working fine now.

The thread mentioned above covers how to disassemble and clean the contact and windings of the sending unit which could be the cause of your problem. Mine seemed to get worse and more frequent erroneous readings over time. It took about an hour and sure beats $300-$400 for a new assembly.

Z06scentair · 11-18-2013

You know this may be worth a shot. The C5 gas gauge was finicky at times, and would stop working. Techron added to the fuel corrected the problem.

You know that ethanol gas is the culprit!

11-15-2013	#1
Z51JEFF Join Date: Dec 2007 Location: Fremont,Ca Posts: 3,079	Fuel gage acting up. Ive got to get my car smogged here pretty soon so Im starting my pre smog workout.As instructed I put a bottle of CRC 05063 fuel cleaner in a full tank of gas and now the gas gage doesnt seem to be working right,wont move below 3/4 tank.I dont drive the car much,maybe twice a month around town.Is my sending unit dying?

11-15-2013	#2
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,155	Re: Fuel gage acting up. Common C4 problem. Make sure you set your trip odometer __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V

11-15-2013	#5
msmoore Join Date: Jan 2013 Location: Nashville, TN Posts: 34	Re: Fuel gage acting up. I recently had the same problem and found a thread on CF that was very helpful. Search for "Fuel Gauge Sending Unit Repair Tech Article" by Frizlefrak in the C4 section. It has instructions and even photos of exactly how to fix it. The only difference is that we have 2 pumps. It was a bit tricky to get the assembly out but with a little patience, it will come out. I went step by step and it worked like a charm. I still reset the trip-odometer but the gauge is working fine now.

11-17-2013	#7
Z51JEFF Join Date: Dec 2007 Location: Fremont,Ca Posts: 3,079	Re: Fuel gage acting up. O.K. heres the deal,Im loosing my mind our Im just plain stupid.As stated I put a full tank of gas in the car with some system cleaner before I get the car smogged.I drive my car a few times a month or whenever I get the itch but Ive been driving abit more to run this tank of gas out.It had been a week since I last drove the car but I knew this tank of gas was just about out but noticed the gage was at 3/4 a tank but had 190 miles on the ODO,I always reset the ODO with a tank of gas.I figure this tank is low at 190 so I go fill the tank and it only takes 5 gallons,5 gallons out of a full tank would be about 3/4 full.Sooooooooooooo,at some point I filled the tank with fresh gas and forgot to reset the ODO,and I dont remember doing it.At least thats all I can think of as to what might have been the problem. Last edited by Z51JEFF; 11-17-2013 at 06:52 PM.

11-17-2013	#8
csavaglio Join Date: Oct 2013 Location: Colorado Springs, CO Posts: 160	Re: Fuel gage acting up. You're not going crazy.....it's all in your head..... I've done that before. I've noticed my ZR1 stays "full" for about 100 miles, then starts dropping rapidly. The '96s I have/had would stay on full for only about 60 miles before dropping, but not as rapidly as the ZR1s gauge shows.

11-18-2013	#10
Z06scentair Join Date: Sep 2013 Location: Charlotte NC Posts: 655	Re: Fuel gage acting up. You know this may be worth a shot. The C5 gas gauge was finicky at times, and would stop working. Techron added to the fuel corrected the problem. You know that ethanol gas is the culprit!