88 crew 454 tbi fuel tank selector issue - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dieseltech619 · 04-10-2018, 04:04 PM

I have owned this truck since November and drive it pretty regularly, i am still chasing down gremlins with it but i have found a new one, my truck is stuck on the left tank. I fuel up atleast once a week amd always fuel the opposite tank to the one im currently running. This morning i fueled up on my way to work and flipped the switch while at speed going down the road and the truck died , i flipped back to the left and it came back to life. I tried this a few more times at different road and engine speeds all the same results. Since i have owned this truck it has had a slight stumble while switch tanks in either direction while going down the road and has always stalled while switching at an idle. I started checking simple stuff fuses and the connections to the switch all seem good but i did notice when i switch tanks the gauge is not changing with the switch it stays at the left reading. Any insight on this would be much appreciated .... thank you in advance

**kwmech** · 04-10-2018, 05:49 PM

You know about pushing the switch all the way to where it springs back to energize the solenoid? Short of that, when the solenoid moves it throws a switch inside the solenoid (switching valve) to swap the fuel gauge.

dieseltech619 · 04-10-2018, 05:52 PM

Quote:

Originally Posted by kwmech

You know about pushing the switch all the way to where it springs back to energize the solenoid?

No i did not but i will try that thanks!

**kwmech** · 04-10-2018, 05:55 PM

Found this

83GMCK2500 · 04-11-2018, 12:15 PM

Here's a semi-recent and informative thread about the dual tanks: http://67-72chevytrucks.com/vboard/s...d.php?t=754061

**kwmech** · 04-11-2018, 10:22 PM

Well? get it figured out

DieselSJ · 04-13-2018, 12:59 PM

Funny mine acted up this morning. Same thing where I filled the tank and hit the switch and it died. Noticed that my fuel gauge was still showing the partial (left) tank that I had been running on. Played with it when I got to work and finally got it to go. After trying a few things, I flipped the switch with the key off and when I turned the key on I heard a thunk and it started working. Started it up and flipped the switch back and forth about a dozen times and all seems OK now.

dieseltech619 · 04-16-2018, 01:55 PM

Quote:

Originally Posted by kwmech

Well? get it figured out

I have not had much time to mess with it, i did try making sure the switch was fully engaged in its position and that made no difference, i don't here any noise out of the valve or the fuel pump when switching. I need to do some voltage checks, and inspect the wiring

**hatzie** · 04-16-2018, 02:31 PM

Quote:

Originally Posted by kwmech

You know about pushing the switch all the way to where it springs back to energize the solenoid? Short of that, when the solenoid moves it throws a switch inside the solenoid (switching valve) to swap the fuel gauge.

Not after 1986... The TBI trucks depend on the power to the valve to run the fuel pumps so GM did away with the obnxious momentary switch they used from 1981-1986..

If you want details on how this system works go to the 73-91 Dual Fuel Tank Theory Of Operation thread and read post #2 for the 81-91 motorized valve system. Ignore Post #1 that's the outline of how the 73-80 solenoid valve system works.

tucsonjwt · 04-17-2018, 05:53 PM

Interesting. My 76 C20 had a positive snap switch for the dual tanks, no springyness to it. My 83 C20 has the spring "delay" type switch. I do know that these switches seem to fail with some regularity. They are cheap enough to just replace, but it is annoying.

DieselSJ · 04-17-2018, 11:56 PM

Turns out the issue the other day wasn't temporary. Can't get it to select at all. Time for new switch. On top of that I got a nasty burning smell in the cab on the way home and engine sputtering and low power. Turns out ECU was crapping out. Opened it up and found a nice burn spot so I get to order one of those tonight also.

**hatzie** · 04-19-2018, 09:13 AM

Quote:

Originally Posted by tucsonjwt

Interesting. My 76 C20 had a positive snap switch for the dual tanks, no springyness to it. My 83 C20 has the spring "delay" type switch. I do know that these switches seem to fail with some regularity. They are cheap enough to just replace, but it is annoying.

Use the 87-91 switch next time. As I stated in the Theory Of Operation post there's no downside to using the later switch.

dieseltech619 · 06-03-2018, 08:34 PM

ended up being the selector switch thanks for the help guys

04-10-2018, 05:55 PM	#4
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,641	Re: 88 crew 454 tbi fuel tank selector issue Found this Attached Images

04-11-2018, 12:15 PM	#5
83GMCK2500 Registered User Join Date: Sep 2009 Location: Beaverton, OR from WA State Posts: 1,515	Re: 88 crew 454 tbi fuel tank selector issue Here's a semi-recent and informative thread about the dual tanks: http://67-72chevytrucks.com/vboard/s...d.php?t=754061 __________________ Devin 1983 GMC High Sierra 2500, 4x4, RC/LB, 400 S.B., SM-465, NP-208, Corporate 10 bolt & 9.5" 14 bolt 1996 GMC Sierra SLE 3500 DRW, 4x4, EC/LB, Vortec 454, NV-4500, BW-4401, AAM 925 & AAM 1050 1997 GMC Sierra SLT 1500 4x4, Z71/F44, EC/SB, Vortec 350 My Introduction with my '83s History New Daily, the '96

04-11-2018, 10:22 PM	#6
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,641	Re: 88 crew 454 tbi fuel tank selector issue Well? get it figured out

04-13-2018, 12:59 PM	#7
DieselSJ Registered User Join Date: Jun 2016 Location: Phoenix, AZ Posts: 574	Re: 88 crew 454 tbi fuel tank selector issue Funny mine acted up this morning. Same thing where I filled the tank and hit the switch and it died. Noticed that my fuel gauge was still showing the partial (left) tank that I had been running on. Played with it when I got to work and finally got it to go. After trying a few things, I flipped the switch with the key off and when I turned the key on I heard a thunk and it started working. Started it up and flipped the switch back and forth about a dozen times and all seems OK now. __________________ 87 R30 CC Dually, TBI 454, NV4500, zero rust barn find 87 Jeep Grand Wagoneer, 6.5 turbodiesel, 700R4

04-17-2018, 05:53 PM	#10
tucsonjwt Registered User Join Date: Jul 2007 Location: Tucson, AZ Posts: 3,189	Re: 88 crew 454 tbi fuel tank selector issue Interesting. My 76 C20 had a positive snap switch for the dual tanks, no springyness to it. My 83 C20 has the spring "delay" type switch. I do know that these switches seem to fail with some regularity. They are cheap enough to just replace, but it is annoying.

04-10-2018, 04:04 PM	#1
dieseltech619 Registered User Join Date: Jan 2013 Location: wilmington Posts: 63	88 crew 454 tbi fuel tank selector issue I have owned this truck since November and drive it pretty regularly, i am still chasing down gremlins with it but i have found a new one, my truck is stuck on the left tank. I fuel up atleast once a week amd always fuel the opposite tank to the one im currently running. This morning i fueled up on my way to work and flipped the switch while at speed going down the road and the truck died , i flipped back to the left and it came back to life. I tried this a few more times at different road and engine speeds all the same results. Since i have owned this truck it has had a slight stumble while switch tanks in either direction while going down the road and has always stalled while switching at an idle. I started checking simple stuff fuses and the connections to the switch all seem good but i did notice when i switch tanks the gauge is not changing with the switch it stays at the left reading. Any insight on this would be much appreciated .... thank you in advance

04-10-2018, 05:49 PM	#2
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,641	Re: 88 crew 454 tbi fuel tank selector issue You know about pushing the switch all the way to where it springs back to energize the solenoid? Short of that, when the solenoid moves it throws a switch inside the solenoid (switching valve) to swap the fuel gauge.

04-17-2018, 11:56 PM	#11
DieselSJ Registered User Join Date: Jun 2016 Location: Phoenix, AZ Posts: 574	Re: 88 crew 454 tbi fuel tank selector issue Turns out the issue the other day wasn't temporary. Can't get it to select at all. Time for new switch. On top of that I got a nasty burning smell in the cab on the way home and engine sputtering and low power. Turns out ECU was crapping out. Opened it up and found a nice burn spot so I get to order one of those tonight also. __________________ 87 R30 CC Dually, TBI 454, NV4500, zero rust barn find 87 Jeep Grand Wagoneer, 6.5 turbodiesel, 700R4

06-03-2018, 08:34 PM	#13
dieseltech619 Registered User Join Date: Jan 2013 Location: wilmington Posts: 63	Re: 88 crew 454 tbi fuel tank selector issue ended up being the selector switch thanks for the help guys



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