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

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.

Re: 88 crew 454 tbi fuel tank selector issue
 

No i did not but i will try that thanks!

Re: 88 crew 454 tbi fuel tank selector issue
 

Found this

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

Re: 88 crew 454 tbi fuel tank selector issue
 

Well? get it figured out

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.

Re: 88 crew 454 tbi fuel tank selector issue
 

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

Re: 88 crew 454 tbi fuel tank selector issue
 

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.

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.

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.

Re: 88 crew 454 tbi fuel tank selector issue
 

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.

Re: 88 crew 454 tbi fuel tank selector issue
 

ended up being the selector switch thanks for the help guys