Help with odd noise under FJ60 dash

[tcb76cruzr]

I have a 83 FJ60, all stock with all emissions in good working order (I think), good running motor. Get right at 300 miles per tank of gas, running 31's with a 5-speed transmission. When its driven though, and turned off to run into a store or whatever for 5-20 minutes, get back in and crank it, a weird noise occurs right when I hit the ignition. Like a pressure release noise under the passenger side dash. It has a odd smell to it, like methane maybe, it is not a gas noise. And it does not want to start right away, have to crank it, when it does start it misses like there is air in the gas line. I drive about 5 miles and it runs perfect again. The carb cooling fan quit working a while back and I have been tinkering with it but have not licked it yet. I think if the carb cooling fan worked it would help the warm restart and running rough, but the dash noise blows my mind. It is geeting worse in the past few monthes. Anyone have any idea?? Thanks in advance.

 

[saint60]

are you sure it is coming from the inside? it sounds like it may be a backfire. does it start right up when it's cold and just have probs with the warm start?

 

[GLTHFJ60]

I don't know about the noise, but it probably dosen't want to start correctly because of the fact that the cooling fan dosen't work. The fan is in place to cool the fuel lines and manifolds for two reasons, so that things don't crack, and so that the fuel dosen't evaporate in the lines nor in the bowl. What I think is happening is that the hot engine is evaporating the fuel in the bowl of the carb, and the lines, making it hard to start. It is starving for fuel because the fuel is vapor near the engine. Cool fuel needs to make it up to the carb before it can start correctly.

 

[CardinalFJ60]

vaguely remember something...

So...I hate use the "S" word...but do a search on this. For some reason, I recall reading a post about something like this. It's on the board somewhere.

I wanna say there's a tiny 'explosion' somewhere near the firewall or something, and the smell is somehow vented into the cab. (Don't quote me on that, I could be totally off base)

Yeah - I know, not much help...

 

[toyman317]

That noise on the pass. side of the dash is pretty normal. That sounds like the noise from the distributor vent tube which ends behind the dash at a filter. What you are hearing is the detonation of vapors inside the distributor. Correct me if I am wrong but all sixty series have this arrangement.

 

[hammer1]

its like a little "pop", right?
i remember a thread saying its a vent from the dizzy, where for some reason fuel vapor gets trapped there, and the spark in the dizzy ignites it.
mine does it sometimes, and it has an electrical smell to it. its been doing it on and off since i bought the truck, never seems to effect anything else.

 

[GLTHFJ60]

The dist. fuel vapor thing must be the sound. I admit that I have never heard it, but others have referred to it. Something about the fuel tank venting into the rubber boot over the dist or something. I don't remember.

 

[tcb76cruzr]

You guys are so mush help, thanks. Without this forum I would be so lost. If I took this problem to a mechanic shop they would look at me like I was nuts, and charge me $200. Anyway, that is the sound, a S noise with a electrical smell. Has anyone ever rewired from the wire harness/cooling fan motor to the sensor on the manifold for the cooling fan. My wire is all burnt up, I've repaired it three times and it still won't work. There is a funky connector there, can I bypass that and run a simple wire from the harness/cooling fan motor to the sensor.

 

[BJ60NZ]

Check these out. . .

Just a couple of threads on this subject.

https://forum.ih8mud.com/showthread.php?t=36475&highlight=distributor+vent

https://forum.ih8mud.com/showthread.php?t=27848&highlight=distributor+vent

https://forum.ih8mud.com/showthread.php?t=12110&highlight=distributor+vent

HTH