• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Where's the Torque?

Professor Bobo

Professor Bobo

NAXJA Forum User
Location
Casco Township, Michigan
I have a problem with my 93 XJ, that someone here could maybe shed some light on. When driving/accelerating the the engine will not exceed 3500 to 4000 rpm! I can acclerate upto the RPM and then it just loses power. No stall, no sputter, no backfire, just flat... no power, like a rev limiter. I have changed the fuel filter, new plugs, wires are less than a year old. K&N airfilter is good. Exhaust is ok...muffler has a hole in it.

Any Ideas? I'm confused.

TIA
 
Have you had the distributor out? I've seen this if the indexing is off.
 
I have not had the distributor out. The cat is rattling real bad but I've had that happen on another jeep I owned. I was told it is a "loose cone". Maybe, when we get a break in the weather here, I will "remove and discard" it. (shhhhhh, don't tell anyone).
 
Professor Bobo said:
I have not had the distributor out. The cat is rattling real bad but I've had that happen on another jeep I owned. I was told it is a "loose cone". Maybe, when we get a break in the weather here, I will "remove and discard" it. (shhhhhh, don't tell anyone).
Click to expand...

That's the prob. The rattling is the honeycomb crap that's in there. It's kind of like ceramic material that gets hot and burns off emissions when the gas passes through. When it gets whacked, or old, it breaks apart and could even clog your muffler. I would take care of it ASAP. Mine broke and a big chunk landed up clogging the output. Couldn't go faster than like 30 and that can't be good for your engine.
 
I am going with CAT, happen to me about a week after I installed a low restriction CAT. It literally came a part on the inside and clog the exhaust. Now my cat is there but I can say it does little to clean exhaust if you know what I mean. If not cat, it still sounds like a very restricted exhaust somewhere.

Bill
 
old_man said:
Have you had the distributor out? I've seen this if the indexing is off.
Click to expand...
Tom,

I'm having a very similar problem. When cold, I'll start rolling fine, but when the R's get to around 2k, the motor looses most of it's power.

I can race the motor just once and things will start working proper.

It feels like the vacuum advance(old school, old_man) isn't advancing.

I rmvd&rplcd the cap, rotor, plugs and wires about 6 months ago.

I have not had the distributor out .

Tell me more about the indexing being off.

:banghead: Thanks, Mike
 
Last edited:
I think I'm gonna do an "exploratory surgery" on my cat converter tomorrow... with my Saws-All, weather permitting. I'll let you know of my findings.
Thanks
 
The cat was the problem. There was a "ball" shaped piece of the brick in there a little bigger than a fist. I think when the flow got high enough the ball would roll to the output and work like a check valve! All is well now!

Thanks ALL!
 
I bought mine from Summit Racing. It was a high flow and I think it only cost about $65.

If you don't replace it the o2 sensor won't heat up to operating temperature and your truck won't run right. It thinks it's trying to watm up and dumps too much gas. Shitty gas mileage...
 
Has anyone else found this to be true... about the O2 sensor etc.
Sorry Jeep914X4.

Jeep914x4 said:
I bought mine from Summit Racing. It was a high flow and I think it only cost about $65.

If you don't replace it the o2 sensor won't heat up to operating temperature and your truck won't run right. It thinks it's trying to watm up and dumps too much gas. Shitty gas mileage...
Click to expand...
 
Professor Bobo said:
Has anyone else found this to be true... about the O2 sensor etc.
Sorry Jeep914X4.
Click to expand...

It's all good. You can't believe everything someone posts on a forum.

This link talks about the o2 sensors need to heat up for it to work right.

http://www.naxja.org/forum/showthread.php?t=899831&highlight=open+Loop+converter

I can't find where I read that the catalytic converter helps the 02 sensor heat up. It's been a few years since I replaced mine but I remember reading it somewhere on this site.

Anyone?
 
Wallyman said:
"the o2 sensor won't heat up to operating temperature and your truck won't run right. It thinks it's trying to watm up and dumps too much gas"


HAHAHA ooohhhh man thats good...its purpose is to warm up the O2 sensor?
Click to expand...

I never said that was it's purpose. :rolleyes:

I thought it played a part in heating up the 02 sensor.

While the catalyst inside the converter is converting carbon monoxide into carbon dioxide, hydrocarbons into carbon dioxide and water and nitrogen oxides back into nitrogen and oxygen it gets very hot. I was lead to believe that it helped heat up the 02 sensor to operating temps.

Maybe someone just wanted me to run a cat. I could be wrong about it heating up the 02 sensor.

I would think that taking it off would reduce the back pressure to the point it would hurt performance also.
 
Wallyman said:
Sorry, i understand your point.
I got cought up in the fun of it all. Im not trying to be an arse hole....
Click to expand...

It's all gravey.

Now that I've been looking around, I can't find anything that verifys my previous belief.

The only thing I can find negative about removing the cat is the back pressure. Unless you have a 96+(I think?) where there is an 02 sensor before and after the cat. In that case the downstream 02 sensor will make the CE light come on.

So Professor BoBo, I guess you could run without a cat. I will personally always run one. I don't want those harmful fumes pouring out when I have to start the jeep in the garage, or when I forget to put my drain plugs in.

CATCO was the brand of the replacement I got from summit.
 
You must log in or register to reply here.

Similar threads

B
Jeeper needs Help !!
2
Replies
22
Views
3K
denverd1
denverd1
E
Odd engine problems
Replies
11
Views
632
Ekacpuc
E
B
Renix engine issues
Replies
7
Views
915
cruiser54
C
C
Overheat
Replies
6
Views
615
kastein
kastein
Hypoid
Power Steering oddity
Replies
7
Views
1K
Hypoid
Hypoid
Back
Top