1986 Jeep Grand Wagoneer

The first thing to check is the ignition system, because components are cheap and easy to replace or inspect. Plug wires can do this. You would feel silly working on a carburetor all day, and then finding out you had a cracked distributor cap.

Which engine do you have?

Saludos cordiales,

Earle

1986 doesn't have that much that can go wrong. I'd suspect a cracked sparkplug, bad wire, or cracked cap/rotor that's preventing one of the cylinders from getting spark. That gas is pushed out and subsequently lit by the cat.

I've had sparkplugs that looked good but arced internally. Also had a few that fell apart when they were removed. Go get some good Autolite plugs.

Engine is 4.9L V8. Wires, plugs and distributer cap replaced about

3000 miles ago. Car was running fine up until that point, however I had just refueled 30 miles previous after letting fuel run too low (gauge is tempermental). Thought I may have picked up a vapor lock along the way. I will pull the plugs tonight though and look for any tell tale signs.

I'll give it a shot thanks. I do get a large amount of gas vapors coming out of the carb tho when the air cleaner is off. Would faulty spark plugs cause a flooding condition because it will run for about ten seconds and then quit. It will start again if I let it sit for an hour or so, but the same symptoms appear.

Thanks Jim

I think spark. The fuel is there for sure.

Even if something like the float stuck, it wouldn't matter above 50 mph.

Was it raining? Maybe a splash of water got the distributor cap and cracked it.

You can do a base check for the timing chain having jumped by putting it on the timing mark on the crank and seeing if the rotor is pointing real close to # 1 under the distributor cap. It should be 'just' after center on the pin.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 (More Off Road album links at bottom of the view page)

A faulty ignition will allow raw fuel into the muffler/cat and cause some nice loud backfires.

Smelling gas out the carb is a different matter. My only experience is with the Rochester 4M4 Quadrajet (Chevy 305 carb) I had a sticking float that was dumping gas into the engine. The floats can also get old and start to soak up fuel, then they don't exert enough pressure to keep the needle valve shut.

I like the FAQ on this site.

No rain, dry as a bone. I will check timing and spark conditions. Maybe I should replace the float as I did not do that with the rebuild, althoughyou said it should not matter at the rate of speed i was travelling.

Thanks to all for your help. I guess I know how I will be spending tomorrow.

Jim

The first thing to figure out here is if it is leaning out or flooding. Lean mixtures tend to backfire on that engine which BTW is a

5.9 AMC V8 not a 4.9. I tend to suspect the fuel pump here and it should be easy to figure out if it is flooding out because there will be a lot of gas pouring in when it dies out. If it is leaning out and dying there will not even be any fuel for accelerator pump if you pump it a few times because bowl will be dry. (it will squirt first time but not much after that) This is not a ignition wire or plug problem. If fuel system checks out the next thing would be the ignition control module. BTW I have owned a AMC 360 for 22 years and counting and I know that engine well.

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Spoken by a truely cluelss guy. On a AMC 360 if float is stuck you will know it at 30, 50 or 70 unless maybe your are WOT but then it would smoke black some and maybe load up a bit. That fuel pump can move a lor of fuel and it can easily flood engine at 50 MPH if float is sticking.

Stick to doing burnouts in reverse to relieve drive line wrap up in

4x4 with your 3.31 power gears and stay away from engines you really know nothing about. You are a real jewel Mike R, a legend in your own mind.

----------------- TheSnoMan.com

You can check the float if you want, but if the float is stuck, the sucker won't be starting up 'easily' at all, it will flood out and stay that way.

You will also see gas pouring down the carb throat if the float is stuck.

You mentioned running out of gas? Have you opened the top of the carb since then?

Sometimes when we run out of gas on our 80's 258's the high vacuum will suck carbon bits out of the charcoal canister which can do strange things inside the carb. Black chunks everywhere.

I know a few that even use a clear gas filter on the carb vent line to stop this because they run out of gas too often.

Mike

Now that was something that brought back memories. i.e. this is the SECOND time I've cleaned this black crap out of the carb, where is it coming from??

(At the time I was not aware the canister had chunks of stuff in it) But that was easily fixed by putting a simple trap in the vac line.

Lose wire on coil to whatever fires it. God Bless America, Bill O|||||||O mailto: snipped-for-privacy@aol.com

Is this a steel or plastic gas tank? Running dry can stir up the rust on the bottom of a steel tank too, but your charcoal cannister theory has a lot of merit.

Saludos cordiales,

Earle

Well Guys,

Again thanks for the help. Most likely a spark problem. Pulled the distributor cap and the distributor ignition pickup wires were frayed with no insulation at all. Put a rebuilt distributor on ( easier than changing pickup and vacuum advance and only $15 more) and it started right up. I ordered a new float which will be in Mon. pm and my problem will be solved. A new muffler and set the timing and I will be back on the road.

Ciao

Jim

Thanks for the update.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's - Gone to the rust pile... Canadian Off Road Trips Photos: Non members can still view! Jan/06 (More Off Road album links at bottom of the view page)

Make sure you replace needle seat for float too.

----------------- TheSnoMan.com