Howdy, This is my first Toyota of the 86 vehicles I've had in my life. I bought a one owner 1986 4x4 pick up almost a year ago, and love it. I've had zero issues at all, until now. I've got 40 yrs of auto repair experience, mostly GM, some Mopar, very little Ford. So, Wednesday, I fill up the truck on the way to work. I thought I smelled raw gas, but wrote it of to a fresh fill up. I didn't smell anything on the way home Wednesday afternoon. Thursday am, I definitely smelled raw gas, so that afternoon I cranked it up and observed a leak at the fuel pump. NBD, I picked up a pump on the way home, swapped it out in probably 15 minutes ( way easier than the GM stuff I'm used to working on ) verified that there was no leaks, and called it good. No smells Friday am on the way to work, BUT when I was leaving in the afternoon, I could see/smell gas leaking from 20' away. Brand new fuel pump leaking at the same place ?!? Drove it home, pondering the problem. I replaced the inlet line as well as the return line rubber hoses, used fresh clamps, and restarted it. It ran briefly, and died. I could restart it, but it would die again. R & R'd the hoses, just in case I was pinching something. I then faintly remembered something about charcoal canisters, so I unhooked both of them, blew air through them, left them unhooked and tried to start it. It now runs fine, but I "think" I still see a tiny gas leak at the diaphragm seam just like before, only much less. I have the gas cap barely on, so I would think it's venting. What am I missing? Thanks, Hank
Toyota noob totally bumfuzzled (1 Viewer)
- Thread starter 67caprice427
- Start date
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First, welcome to our slice of MUD ... 
<- official MUD welcome salute.
Thoughts.
1- tighten the gas cap. I know it sounds counter intuitive, but I have issues with mine if the cap is cracked. Make it tight and the leaks stop. It could also be an old/bad gas cap.
2- Did you use a Toyota pump? I know they are 10x aftermarket, but this might be a case of "you get what you pay for."
3- If the charcoal canister is leaking it would be out the purge port on the bottom. I seem to recall that carb'd truck had two canisters, at least in Gen1 trucks.
4- Be careful blowing air into a charcoal canister. I think it's possible to damage the filters inside.
Here is a page from the Factory Service Manual on inspection of the canisters.
<- official MUD welcome salute.Thoughts.
1- tighten the gas cap. I know it sounds counter intuitive, but I have issues with mine if the cap is cracked. Make it tight and the leaks stop. It could also be an old/bad gas cap.
2- Did you use a Toyota pump? I know they are 10x aftermarket, but this might be a case of "you get what you pay for."
3- If the charcoal canister is leaking it would be out the purge port on the bottom. I seem to recall that carb'd truck had two canisters, at least in Gen1 trucks.
4- Be careful blowing air into a charcoal canister. I think it's possible to damage the filters inside.
Here is a page from the Factory Service Manual on inspection of the canisters.
- Thread starter
- #3
So, I fired her up this am, and she was leaking like the Titanic-I tightened up the gas cap and after she warmed up-no more leaks on the way to work. When I shut the truck off, in about 1-3 minutes, she starting leaking again. I reattached all of the charcoal canister lines,started her back up-no leaks. i drove it home this afternoon, the only time I smelled any gas, was waiting for an exceptionally long light change. I went to the store, when I got out, I smelled gas. I drove the 1/2 mile home, no more leaks. I shut it off- leaks in about 1-3 minutes- crank it back up & no more leaks within a minute or two. Do I need a priest for an exorcism or what. BTW, I ordered a Toyota pump, will be here in a couple of days. Also, air nozzle used was OSHA 30 psi, so no over pressure.
That is what I was thinking. Are the vents hooked up to the manifold correctly? Are any of the ports blocked? There is a vacuum switching valve. Is it working properly, or even plugged in? I've attached the pages from my 1985 manual on the subject. It should be close to what you have.
- Thread starter
- #6
All of this started on Wed, when I filled the tank. I'm been driving this vehicle almost a year with no problems/issues of any kind. Everything I've done is an attempt to combat the leak that appeared to come from the diaphragm seal on the fuel pump. Any lines removed were replaced as found, only parts replaced were the pump, and the inlet/return rubber hoses & clamps.
Old part leaks: Worn out
New part leaks: Manufactured to the same tolerance as 35 year old parts, or the 8 year old chinese kid was still apprenticing and let one slide.
Bad new junk fuel pump: hard start or no start.
Try another new one and call it a day.
New part leaks: Manufactured to the same tolerance as 35 year old parts, or the 8 year old chinese kid was still apprenticing and let one slide.
Bad new junk fuel pump: hard start or no start.
Try another new one and call it a day.
- Thread starter
- #8
UPDATE!!!!!!!!!!!! Replaced new Delphi pump with brand new TOYOTA pump and woo-hoo!!!!!! NO MORE LEAKS!!!!! what a pita this little trip has been. Thanks to everyone, and I went ahead and replaced the gas cap for good measure.
Another win for OEM parts.
