97 Wrangler. Chugging after warms up.

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I have this problem that my Jeep starts chugging and seems like the Cataletic converter is pluged (except I took it off months ago for the same type of problem). Once the Jeep warms up after about 2 or 3 miles it starts chugging and feels like its flooding out. I can stop and let it run for a bit and then it starts to smooth out. Once I get going its back to the same thing. It feels like I have 13 1/2 - 1 pistons and a nice cam. Anybody have any good ideas? :banghead:

posted by  RollmeBackover

Fuel injectors/pump?

posted by  newyorker

Okay, I'm game. Why would the "fuel injectors/pump" cause this to happen? You better have a good answer because you gave the response. Justify it.

posted by  vwhobo

If the injectors are clogged, they arent letting in a proper ammt. of fuel, and that might cause the engine to struggle. Aso the pump may not be pumping right, so that can be a cause. It was just a guess man. :laughing:

posted by  newyorker

I have an idea on the o2 sensor the sensor to the Cat. convert. isn't even there. Could this be it? :screwy:

posted by  RollmeBackover

is this a 2.5l or 4.0l?
are you sure its not starving for fuel rather then flooding?

posted by  windman

You need to start here (http://www.car-forums.com/talk/showthread.php?t=2200) and resubmit.

posted by  vwhobo

I have a 97 wrangler 4 cyl. 5 speed man. 33" tires and 4" lift. It has 77,000 on it and I have removed the cat. conv. due to same type of problem. I have checked my plugs wires and cap all look like the day I put them in 6 months ago. I thought I heard an air flow noise so I removed my muffler and put on a strait cheery bomb. Still the same prob. it just sounds like a white trash mobile now. I cant seem to find the shrader valve to check my gas flow but I'll keep looking. The gas gauge seams be moving up and down between 3/4 and full when this happens. and the exaust smeels funny, not like gas but different. Then when it goes back to running smooth the smell goes away. Thats about as much as I can think of for now. I hope thats better. :thumbs:

posted by  RollmeBackover

DTC's?

P.S. Colored letters aren't cute.

posted by  vwhobo

what did you do with thedownstream heated oxygen sensorconvertor on the rear of the cat when you removed the cat?

posted by  windman

I can read them better.

posted by  RollmeBackover

When I removed the Cat. I unpluged the sensor and removed it as well. I allways have a check engine light on but what ever.

posted by  RollmeBackover

so you just threw it away thinking wtf is this for i dont need this??? :screwy: :laughing:

posted by  windman

So are you going to give us the DTC's, or are we supposed to guess?

posted by  vwhobo

No, I didn't chuck it. I have it laying on my work bench wraped up so that when I put a new Cat. on for DEQ. I can pass. I might not know a whole lot but I know enough not to throw things like that away.

posted by  RollmeBackover

I'm sorry but what the heck are you asking for? Whats DTC?

posted by  RollmeBackover

i didnt see your answer b4 i asked that last question
i would start by replaceing the cat and the rear oxygen sensor
oxygen sensors tell the computer how much air fuel to deliver
no signal (i would think) would tell the computer to load more fuel
hense your flooding sensation
its never a good idea to just discard any sensors
as they tend to run in series with other sensors selanoids ect and affect how everything else functions accordingly
wait and see what the hobo has to say as im just taking a guess here
as he asked did you retrieve any codes?
which may be quite useless being as you have 1 sensor completly not there and may cause other codes to come up because the system is lost
good luck!!

posted by  windman

diagnostic trouble codes

posted by  windman

DTC - Diagnostic Trouble Code. This is the first bit of required information when working on computer controlled cars... Especially OBD-II cars.

posted by  vwhobo

Well, uh, no. The only thing the downstream HO2S does is read to the PCM so it can perform calculations to determine the operating efficiency of the catalytic convertor. It in no way controls engine operating parameters.

posted by  vwhobo

codes can be retrieved from a digital odometer or the mil light
attempt to start engine but dont start it (let it crank once)
turn ignition switch to off then on off on off on
all within 5 seconds
watch the mil light flash and count flashes
ex blink blink pause blink pause
code 21
if you have a digital odometer the code may come up on there aswell the odometer reading will be replaced by a dtc
say 21 oxygen sensor
im not sure with jeep but the codes might flash the same code three times before giving the next code
so pay attention
scan tool is better then lights because they can distinguish the codes better then the mil or odometer

posted by  windman

ah ok so its just the front o2 sensor that controls fuel ratio ect?
good to know
tanks

posted by  windman

Don't think front, think upstream. And don't forget that all OBD-II non-inline engines have two upstream sensors. Also, some cars don't have an upstream oxygen sensor at all, instead they use an air/fuel ratio sensor. Lot's of Toyotas (and of course Lexus') come to mind. It performs the same function in a different way while costing three times as much.

posted by  vwhobo

upstream being before the cat?
i'm haveing a hard time comprehending upstream from down considering its all going in the same direction out the tailpipe
appreciate the clarification thanks

posted by  windman

Upstream is before the cat. Downstream is after the cat.

This cat has been IN the stream.
http://www.wtv-zone.com/no_u_turns/images/wet-cat.jpg

posted by  vwhobo

ok great thanks :thumbs:
im thinking he is out getting codes :clap:

posted by  windman

I will check the codes tonight when I get home. Where can I get a copy of what the light counts mean? Do you think the upstream sensor could be the problem or is it something more basic like fuel filter? I'll let you know what I find out. It's good to know you guys are out there to help. This prob. saved me hundreds at a shop. I can't thank you enough.

posted by  RollmeBackover

troble code chart
http://jeephorizons.com/phpbb/viewtopic.php?t=2719

posted by  windman

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