Fuel Selector Switch....

Can't go anywhere without a working drivetrain
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Choptop
Seasoned Traveler
Posts: 390
Joined: Sat Aug 26, 2017 8:28 pm
B190 Year: 1990
WBCCI: 0
Location: Midwest

Re: Fuel Selector Switch....

Post by Choptop »

Abie Sea wrote:I have been checking all around the internet to gain more information on this problem. The more likely situation even with the fuel transfer, it that the fuel selector switch is not sending the return flow to the right tank. If this is the case, then there is no need for a check valve in the tank. These are the most informative links. http://www.blackeagle12.net/F150/Dual_T ... ector.html and https://www.youtube.com/watch?v=qBE3LWWmelM . The video was most informative. Hope this helps.
Watched that video along w/a couple of other ones that loaded after it, very informative, will have to get under the B to see what system I have going on their, have no problems at this point but to know what the possible problem is and how to fix it, should their become a problem is golden. Thanks for the video !!
Abie Sea
Weekend Camper
Posts: 40
Joined: Fri Oct 23, 2015 6:29 pm
B190 Year: 1989
Location: Seattle

Re: Fuel Selector Switch....

Post by Abie Sea »

I have been dealing with this problem for a while. When the engine load was heavy going up hill and in hot weather or both, the engine acted like it was not getting gas. It recovered when allow to set for a half hour or so, and would run well if the switch selected the rear tank rather than the front tank. I was resigned to having the fuel pump replaced. I did not want to deal with the action mentioned in this post and elsewhere on the internet. My mechanic could not find a problem and was dubious that that would be the problem, but attached a pressure gauge to the engine end of the pump and asked me to see if I could get it to stall. It was in May and the temperature was not too hot. I must have burned up 30 gallons running up and down the freeway on hot days trying to recreate the problem. Previously it had happened on the freeway at temperatures in the high 80s, but not on the first two trials. The third time was a charm and the engine decided to quit doing up a narrow grade into the cascades. It was a difficult situation with the traffic and not shoulder, but I did barely make it to a small turnout. I did notice that the fuel pressure dropped to O during this moment of panic, indicating that there was a problem getting fuel from the front tank to the engine. I was able to replicate this situations on several other occasions and noted that on a straightaway I was able to switch to the back tank and get the engine running again after losing fuel pressure to the engine from the front tank.

The mechanic indicated that the switch activated a switch in or at the fuel pump and replaced that in the expectation that that would cure the problem. We are off on a two week trip and we will see whether we have found the cure.
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