82 SJ Not Starting When Hot

"Dual" fuel. Choke adjustment could be off, closing too soon. According to this scenario, your engine is still warm, but your choke has closed. Check this, before you try to start the vehicle, by visually inspecting the position of the choke butterfly. I don't know for sure what your dual fuel carburetor looks like, or even if it has a choke, but check anyway.

There is a condition called "vapor lock", which is in general caused by too much heat under the hood (bonnet?). A possible cause is a stuck closed choke preheater butterfly. How to find this, depends on your engine model, I6 or V8. It will be in the exhaust manifold, where all the branches come together. A work around, is to open the hood (bonnet?) after running a while, to see whether cooling the engine with fresh air eliminates the problem. A high temperature lubricant can be used on the butterfly pivots. Consult your local parts specialist.

There is an English fellow who frequents this newsgroup, with a 91 Wagoneer, who may have some ideas.

Earle

probably the crank position sensor (cps) needs to be replaced. it is a common problem and you can do it yourself with a good flexible socket wrench,and a lot of twisting around. it is on the outside of the bellhouseing drivers side 2/3 way up with a plug under the hood. carefull not to drop the bolts inside when removing them(2) about 40.00 for the part. old john

Hello, Dave! You wrote on 3 May 2006 22:13:33 -0700:

D> Have an 82 SJ Cherokee that wont start after its hot. Fine starting D> cold but after running for a while, wont restart...especially if i go D> out, come back, leave it a while then try to start it up again.

D> Turns over ie cranks fine... battery, coil, starter and fuel pump have D> just been replaced.

D> Its been converted to duel fuel ie LPG and petrol. Originally after D> driving for a while on LPG it would cut out and wouldnt start again D> until it had cooled down. Thought it was LPG related so switched to D> petrol. Didnt cut out on me but after going driving for about 20 mins, D> came back, left it an hour then tried to start again.. but it just isnt D> happening. Just keeps cranking but nothing else

D> Hopefully someone has some ideas what the problem is.

D> Thanks for any help with this.

D> Dave

With best regards, snipped-for-privacy@comcast.net. E-mail: snipped-for-privacy@comcast.net

They had computers in 1982????

He still hasn't said what engine is in the beast.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: N>

It would be carbureted, but I haven't seen a dual fuel carburetor in years, so I couldn't give detailed advice. Around here, LPG is probably still cheaper than petrol, but no one knows how long this situation will last. A few years back the tree huggers were touting LPG and LNG as safer, cleaner, environmentally friendly alternatives to gasoline, but all three come out of the ground, and all three will exhaust supply after the wells dry up.

Earle

snipped-for-privacy@comcast.net

Sorry... its the original AMC 5.9L V8

It has the original carb in it. The dual fuel conversion placed another piece that fits over the top of the carb that the air filter sits on. The whole thing lifts off once u unscrew the usual air filter nut.

Thanks to all for the advice. "seems" to be running ok at the moment. Definitely an issue with the LPG.. probably some solenoid's faulty.. as for petrol... the choke isnt staying on when its hot... but it does seem to be too muhc fuel related. Seems to be running very rich and i think the restart issue when hot is actually related to it flooding REALLY easy. Ill tune that and see how I go...

Thanks again for all the help :)

btw.. even though LPG prices have risen lately.. its still 1/3 the price of petrol here in Sydney... so still cheaper to run. Prefer running on petrol but saves a LOT of money when doing some long runs...

Dave

Did they use the dual outlet gas filter with the return line in 82? That was put in to stop vapor lock which causes flooding and no starts when hot....

I do see lots of those disconnected due to rusty lines...

You might want to change the routing of the gas line if it is just a single line.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >

cool.. thanks for the advice... ill check it out :)

Dave