Flame out the tailpipe and popping above idle

Well I hate to start another thread since I fused this question into a previous one but I need to get this figured out ASAP. I replaced my tranny and got done today. Started it up, the tranny is in good working order as far as going through the gears and all. The problem is if I give it any gas, it backfires something fierce and has no power at all, it just sits there popping, it idles just fine though. Also when I tried it tonight my Dad was behind the Jeep and saw about a 3" flame come out the tailpipe. What would make it run so rich? I can only think of three things.
1. The CPS went bad in the three days I had it off. It doesn't need to be at a certain spot in relation to the flexplate does it? To line my torque converter up, I had to spin the flexplate without the CPS online, does this matter?
2. The 02 sensor was sitting out in the rain in my exhaust pipe-do they not like moisture?
3. I put about 2 gallons of gas in that has been sitting for 6 months, a couple of those out in the snow. Lid was on tight and all that but still... As a safety precaution after I emptied that in and realized what I did I went and got 5 fresh gallons and poured that in, didn't seem to do anything though.

So what should I start out trying? The flame out the exhaust makes me think it's running very rich so I would lean towards the 02 sensor, but at the same time I suppose bad gas or a bad or misaligned (if possible) CPS could do it too. What do you guys think? Any help ASAP would be fantastic.
Thanks,
Collin

Did you have the distributor out? It sounds as if it might be a tooth retarded (Easy start and idle combined with inability to rev).

I don't think it could be the CPS since in most cases the Jeep just won't run if it's getting cranky.

I don't know if a freaked-out O2 sensor would run the Jeep that rich that it backfires so bad.

Sorry I'm not much help, just a couple of thoughts I had.

I can't see how bad gas would allow it to idle find but not rev......YOU would thing it would be just the opposite.
put a bottle of heat in the tank just to make sure that you didn't dump water in there. A bottle of house hold rubbing alcohol will do the same thing.

You didn't happen to put a gas can full of .......Diesel in it?

If you did you would Know it, because it would pour out tons and tons of WHITE smoke!(If it ran at all)

Flash.

Matthew Currie said:

Did you have the distributor out? It sounds as if it might be a tooth retarded (Easy start and idle combined with inability to rev).

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Nah, the dizzy stayed in the whole time. That is what it sounds like though, but I think it's electrical somewhere.

Flash said:

I can't see how bad gas would allow it to idle find but not rev......YOU would thing it would be just the opposite.
put a bottle of heat in the tank just to make sure that you didn't dump water in there. A bottle of house hold rubbing alcohol will do the same thing.

You didn't happen to put a gas can full of .......Diesel in it?

If you did you would Know it, because it would pour out tons and tons of WHITE smoke!(If it ran at all)

Flash.

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Yeah well like I said I diluted the gas pretty good too with fresh so I don't think that's it. And hahaha no I didn't put diesel in there, we don't have any use for that around my house.

I thought I saw in the Haynes Manual that there is an adjustment for the CPS. I'm not sure, never done it on a Jeep, so I may be very wrong.

As well, is it possible to install it incorrectly, i.e. backwards. Slightly out of positions would allow the CPS to work, but send a very inaccurate signal that would result in ignition timing being very off.

It's not going to be the CPS. More likely a bad O2, TPS, or MAP. You have to be running way to rich. A plugged CAT can cause the problem off of idle as well.

Double check the connections to the MAP first.

As for flame out the exhaust, I think you would have a stuck open exhaust valve.

Turns out my CPS's contact had gotten chipped off so it was almost flush with the body of the sensor itself. It must've been catching just enough of the flexplate to get it to start and nothing more. That was mighty strange. Thanks for the help diagnosing guys.

I have seen kits for "muscle cars" that used a spark plug in the exhaust pipe that would allow you to rev the engine and send power to the plug and it would throw flames.

You just got the "flame thrower" upgrade by accident!

Jess said:

I have seen kits for "muscle cars" that used a spark plug in the exhaust pipe that would allow you to rev the engine and send power to the plug and it would throw flames.

You just got the "flame thrower" upgrade by accident!

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My Dad told me my Grandpa had a setup like that in his 1934 Buick. Apparently yeah you really don't even need a kit if the things run rich enough, you can put a spark plug and a grille ignitor in the exhaust and it will work. Funny thing is my Grandpa was a really quiet, reserved guy yet he did that for fun. I was telling my Dad if we ever want to enter my XJ in like a car show we need to take that CPS an 11mm socket and some extensions with us. But yeah I wasn't a big fan of getting it by accident. That part kinda sucked.

RenixPower said:

Turns out my CPS's contact had gotten chipped off so it was almost flush with the body of the sensor itself. It must've been catching just enough of the flexplate to get it to start and nothing more. That was mighty strange. Thanks for the help diagnosing guys.

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Glad you found the problem, i figured CPS because it really was the only thing you messed with that could cause running issues.

I think your buds snuck a new powerstroke under the hood when you weren't lookin'. :laugh3:

http://www.youtube.com/watch?v=v36MCcRPRTc :flame:

SteveT said:

I think your buds snuck a new powerstroke under the hood when you weren't lookin'. :laugh3:

http://www.youtube.com/watch?v=v36MCcRPRTc :flame:

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Oh good god, mine wasn't quite that bad.