EVAP System bypass? Stalling...

[bkkincaid]

Hi, all. I have a recently purchased '81 Wag. It's run well until recently, when it's started stalling at random times--no apparent trend. Questions:

* Vacuum related stalling vs electrical vs fuel system?:

* Vacuum--
When I first saw the Jeep and looked under the hood, I noticed the EVAP charcoal canister was cracked. Drove fine on test drives, with a slight stumble with quick acceleration. The guy I bought it from said that he had simply "disconnected" the EVAP system. (Not a lot of emissions laws up here in Oregon.) I cleaned out the fuel system with some additives, put a K&N air filter in, and it helped with the stumbling. Like I said, it's ran well for a couple of months, but now is stalling all the time. So, I'm wondering if it's even possible to bypass the EVAP system without causing a vacuum problem? If so, how would that be done, and how would it affect engine performance? Any insight here would be appreciated.

* Fuel system--
The fuel gauge initially wasn't properly grounded, which I discovered by running out of gas at 1/4 tank+ on the gauge. Wondering if this might have sucked some junk into the fuel filter, and if that's perhaps the cause of the stalls.
Haven't checked the fuel pump yet.

* Electrical--
Replaced the coil and moved it to the firewall to keep cool, just in case that was the problem, but it keeps on stalling, so no luck there.

Any help would be greatly appreciated, as I'm just getting into the game.
Thanks!
--ben

[tgreese]

Originally posted by bkkincaid:
I noticed the EVAP charcoal canister was cracked. Drove fine on test drives, with a slight stumble with quick acceleration. The guy I bought it from said that he had simply "disconnected" the EVAP system. (Not a lot of emissions laws up here in Oregon.) I cleaned out the fuel system with some additives, put a K&N air filter in, and it helped with the stumbling. Like I said, it's ran well for a couple of months, but now is stalling all the time. So, I'm wondering if it's even possible to bypass the EVAP system without causing a vacuum problem? If so, how would that be done, and how would it affect engine performance? Any insight here would be appreciated.IMO it's a mistake to remove the vapor recovery system. You need it to properly vent your fuel tank, it doesn't affect engine performance (when functioning properly), and there's almost no maintenence required (just the filter pad).

You can easily test your vacuum leak theory by plugging the manifold vacuum line to the canister. IIRC there's a manifold vacuum line that activates a valve in the canister (on the 3-tap cans), and a low vacuum line that goes to the air cleaner snorkel and actually purges the vapors through the carburetor. The third tap goes to your fuel tank. Only the manifold vacuum line should/could effect performance if it's leaky.

You can scrounge a replacement canister at a junkyard or from one of the board members. There was a thread recently that claimed you could use a can from a GM or Chryco vehicle... I'd suggest a search.

hth :cool: Tim

[letank]

Need to figure if you are stalling because of lack of gas of absence of spark?

is there gas in the bowl... do you see spark when you unplug coil lead and put it 1/4 from a good ground... then repeat with spark plug boot... just connect a spare spark plug to boot.... and ground on exhaust manifold

Michel

[kellysguy]

My 81 J10 was doing the same thing. I pulled the fuel filter and it was full of trash. Changed it out and worked great ever since. If it's not, what's $4 for a filter? I disconected and plugged all my emissions off my 87 waggy and now it runs way too rich and idles rough. There are no vaccum leaks or anything. My advice, don't do it.