View Full Version : [Unresolved] 1989 Ram 50 Vapor Canister Info Needed
Ram50Guy01
02-14-2024, 05:14 AM
I’m having issues with a 1989 Ram 50 2.6L G54B. The fuel vapor cansiter located on the front passenger side of the firewall is leaking gas from the bottom outlet/inlet. I am unable to find any information online as to what that outlet/inlet ties into. If you have anything that would be helpful to me, please feel free to share below. I’m hoping there’s a diagram somewhere but I can’t seem to find one.
FMS88
02-14-2024, 01:48 PM
Does your truck have the Mikuni carb? If so, these diagrams of the Evaporative emission system and its components should help:
http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=28217&stc=1http://www.mightyram50.net/vbulletin/attachment.php?attachmentid=28218&stc=1
With the Mikuni, likely sources of fuel in the cannister are a failed bowl vent valve or a stuck float needle valve. If either of these are the cause, a rebuilt Mikuni, or better yet, a Weber is the best fix
Ram50Guy01
02-15-2024, 05:04 AM
I believe it has the Mikuni Carb. I really appreciate the information you provided, It seemed like a wild goose chase trying to find those schematics.
I’m going to rebuild the carburetor to be safe from all ends regardless but I noticed today that the vapor line going to the tank was dripping today and I ziptied it shut temporarily. I’m wondering if there are any causes from the tank that I should be wary of?
Ram50Guy01
02-15-2024, 05:08 AM
Could you point me in the direction of the proper rebuild lit for the Mikuni carb or even a new or rebuilt Weber if you think that’d do better.
FMS88
02-15-2024, 11:01 AM
I’m going to rebuild the carburetor to be safe from all ends regardless but I noticed today that the vapor line going to the tank was dripping today and I ziptied it shut temporarily. I’m wondering if there are any causes from the tank that I should be wary of?
The Mikuni is a nightmare to rebuild. Plus the only available rebuild kit doesn't include all the parts you need. Get a Weber from Redline or other distributor that sells "made in Spain" carbs. Don't buy a cheap Chinese knockoff. Do a search of this site and you'll find stickies and many, many threads that describe the benefits of a Weber, advise what to buy (carb, electric fuel pump) and how to install them.
In the meantime, plugging the canister line should work. Many web sites or blogs blame a flooded canister on over filling of the tank or thermal expansion. Not sure if that's possible with these trucks, but if it is, keeping the fuel level to less than 3/4 might stop or slow the flow to the canister.
Ram50Guy01
02-15-2024, 04:35 PM
Alright, so I fully closed off the ‘to tank’ vapor line. My truck ran just fine and idled perfectly, where as the carb was bone dry and the truck was unable to start beforehand. My uncle informed me the previous owner had it closed off to begin with and that he actually reattached it to the canister. Do you think it’s still something to do with the carb? Someone else said something about a possible clog in the overfill limiter tube of the gas tank.
FMS88
02-15-2024, 05:18 PM
Alright, so I fully closed off the ‘to tank’ vapor line. My truck ran just fine and idled perfectly, where as the carb was bone dry and the truck was unable to start beforehand. My uncle informed me the previous owner had it closed off to begin with and that he actually reattached it to the canister. Do you think it’s still something to do with the carb? Someone else said something about a possible clog in the overfill limiter tube of the gas tank.
The overfill limiter valve may be stuck open thereby allowing vapor or fuel to flow to the cannister. Keep the tank line closed at the cannister and continue to drive it. If the carb has issues, the truck will drive poorly and mileage will be terrible. But since it seems to drive fine and if it continues to do so, there's no need to rebuild or replace carburetor. Driving it is the best test and it will reveal if something needs to be fixed or not.
Have fun.
Ram50Guy01
02-15-2024, 06:14 PM
Alrighty, will do. Thanks for all the info! I’ll take a few days of driving it around and provide an update afterwards.
SubGothius
02-16-2024, 08:34 PM
Also an object lesson in why to never "top off" the tank at the pump after the nozzle shuts off -- i.e., always take the nozzle auto-cutoff as gospel. Topping off an already nominally-full tank can result in the vapor capture line or canister getting flooded with raw fuel, or damage or jam the overfill limiter, etc.
Ram50Guy01
02-18-2024, 10:54 PM
Alrighty, will do. Thanks for all the info! I’ll take a few days of driving it around and provide an update afterwards.
Alright, so as an update. Pinching off the line has resolved my issue for now. I’m going to check the overfill limiter soon as I’ve been planning to drop the tank to clean it anyways. I’ll provide an update on what I find when I get around to it. I really appreciate the help and information.
FMS88
02-19-2024, 06:37 AM
Thanks for the update and good luck dealing with the tank.
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