• 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.

Can't go above 2500rpm?

O

onesic6

NAXJA Forum User
Location
Northern VA
I can't get my xj to go above 2500rpms, sometimes if im crusing and can get up to 3000rpms but thats its, doesn't matter if its in any gear or neutral. If I floor it it will go up to 2500rpms and just sit there and stumble on itself. it also sounds like I have a turbo now when i push on the gas and im driving you can hear a spooling sound almost. I am thinking it may be a clogged converter but I wanted to get some other opinions and what to look for, I am deff not able to drive to work everyday like this lol. I also tried downshifting to 2nd (its a manual) from a 50mph role thinking maybe it would blow the cat out if it was clogged and this did not work, still the same problem.

Edit: its a 96 and no codes have been thrown either.
 
have you checked the fuel filter?

fuel pressure?

bad tps?

if its not throwing a code, check to see if the cat is clogged or take somewhere to have them check? have you put your hand over the tail pipe to feel how much pressure is coming out?
 
i had a very similar problem with my 98 4.0 ax-15 and i got po'ed at it one night because it wouldn't rev up to 3500 rpms and starting just beating the crap out of it on some back roads all of the sudden i heard a loud bag and chunks of burning cat flew out of the back and was fine imediatly after that a little bit louder but thats it


i would recommend just takeing it off and punching it out or replaceing it way easier and safer then my way lol
 
Why not just put a vacuum gauge on it. If it reads normal at idle, but drops to 0 and stays there when you start increasing rpm's, then I'd say it's your cat.
 
sw4218 said:
Why not just put a vacuum gauge on it. If it reads normal at idle, but drops to 0 and stays there when you start increasing rpm's, then I'd say it's your cat.
Click to expand...


I will have to pick up a vacuum gauge today and try that. on a side note I attempted to get the cat off yesterday but it was very rusted, going to borrow a torch today and heat it up to get it off, one thing I did notice though when i tried to drive it again is it will not start unless I hold the gas to the floor and smells of exsesive fuel and alot of white smoke coming out of the exhaust, I wanted to know if anyone else thinks this is more reason to beleive it be the converter.
 
seen much the same with 2 dodge trucks. no codes, or misfire codes if any.
cat both times, saw-zall it off and start it up, you'll notice immediate change.

96 won't run very well (low mpg) if you just punch out the cat, plus its bad for the environment. replace it with a good high flow one, not that pricy really.
 
beakie said:
seen much the same with 2 dodge trucks. no codes, or misfire codes if any.
cat both times, saw-zall it off and start it up, you'll notice immediate change.

96 won't run very well (low mpg) if you just punch out the cat, plus its bad for the environment. replace it with a good high flow one, not that pricy really.
Click to expand...


Agree with you there, I already got a new stock replacement, I just rather not replace the pipe before the cat and the catback after it since there is nothing wrong with it unless there is no other option.
 
Is it misfiring? We had this exact same thing happen on a grand cherokee. Had a constant miss, but no codes and felt like there was a rev limiter right around 3000 rpms. Turned out to be a busted rocker, the top of it that was supposed to be flat was shaved into a concave bowl. I'll try and get some pics.
 
Got it off today, I was able to salvage the front pipe but the catback was destroyed, all the more reason to upgrade :D

Turned out to be the cat, the thing was broken up bigtime, thanks for everyones help!
 
You must log in or register to reply here.

Similar threads

V
High temp woes
2
Replies
21
Views
414
Vitzaa
V
F
Stumped on this one!
2
Replies
29
Views
4K
Bent
Bent
O
0331 Strikes Again...?
Replies
11
Views
301
Ol Blue
O
A
2000 xj aw4 on 34s 4.88 or 5.13
2 3
Replies
49
Views
5K
Andre2000
A
N
Severe stumble, misfire and no start issues
2
Replies
27
Views
4K
maxbraketorque
M
Back
Top