Topic: 1990 2.5l backfire

[chardrc]

i have a 1990 yj with the 2.5l tbi 4banger. and when i got it it would backfire when ever you would shift. but after we took out the motor and put it back in to replace the clutch the back fire went away... but now that i am driving it more it is starting to backfire again when you shift. not as bad as befro but it happens.. ow ya it used to leak oil so that has hurt some of the vacum hoses even after we tried to clean it and we are constintly having to replace then(different ones just a mater of seeing that they are bad.

so what im asking iw what to look for to find the casue of the backfireing to solve the problem..

thanks in advance for any replies.

[BK2LIFE]

i think i have seen this somewhere else on this site, do a search and see if you can find it.

if i remember correctly, the higher mileage motors suck oil really bad and causes a hot post in the combustion chamber causing the back fire.  
also i might have seen it on another jeep site i go to, i dont know if jeff would be ok with me listing the other site here.. jeff?

[chardrc]

ok ill do a check quick.. (ive never been good at searching forums other than going through each thread individiualy and thats why i just made a thread.)

[chardrc]

hmm i did a seach in this site and found some stuff but not as good of info as what you were hinting at.

[BK2LIFE]

also what about exhaust leaks?  i know mine will back fire if i high rev it then shift, like tryin to go up a steep road then shifting to the next gear.
jeff didnt respond so ill tell the other site it might have what i was thinkin about  www.oahujeepers.com

-james

[Jeffy]

also what about exhaust leaks?  i know mine will back fire if i high rev it then shift, like tryin to go up a steep road then shifting to the next gear.
jeff didnt respond so ill tell the other site it might have what i was thinkin about  www.oahujeepers.com

-james

Interesting.  Does Ken Kelly still have a Jeep or active there?  I used to run a Hawaii 4wheeling section on my old forum.  That's where it all started.  Then there was a falling out when some of the Jeepers didn't want to associate with the Hardbody or Taco crowd.  So, everyone left and Pyro, from the Big island said he'd support the Jeeper forum.

Interesting to see that it turned into an actual club with a board.

As for outside links, that's ok as long as it's not a blatant attempt to steal traffic.

[chardrc]

i sure hope there are no exost leaks anymore.. there was a big hole right befor the cat.. so i took it in and they put in a new down pipe and id asume they checkled the rest of the exost... but then again you can realy asom anything anymore...


"i know mine will back fire if i high rev it then shift,"... ow thats what hapens to mine... is that normal well kinda normal or is it something that should be fixed sooner rather than later?

ow ya thanks for the link ill checkl it in 1 minute.

[jwrape]

Mine backfires too. I just replaced the muffler because it was rusted out and thought it would stop the backfiring but it only reduced it.
Mine only backfires when I drive it hard.

[Jeffy]

Wow, reviving a bunch of old thread.  Why not start your own?

[jwrape]

Wow, reviving a bunch of old thread.  Why not start your own?

I had my own a while back and still can't figure it out. Been backfiring for almost a year I guess.

[jwrape]

Wow, reviving a bunch of old thread.  Why not start your own?

http://www.4bangerjp.com/forums/viewtopic.php?t=1034&highlight=

Seems to be a problem that won't go away

[chardrc]

ya it still hapens to me... but ive learned that if you give it alittle gas befor leting the clutch out when shifting it will stop the bacvkfire... kinda finicy adn takes time to get used to but it works.. but i am missing a the farthers forwoed stud/bolt on the exzost manifuls so that could be part of the isue.. for me its more if the motor is worm or not.. if its warm it will backfire more.. if its cold it wont backfire.... but then again i take it easier when its not warmed up.

[jwrape]

ya it still hapens to me... but ive learned that if you give it alittle gas befor leting the clutch out when shifting it will stop the bacvkfire... kinda finicy adn takes time to get used to but it works.. but i am missing a the farthers forwoed stud/bolt on the exzost manifuls so that could be part of the isue.. for me its more if the motor is worm or not.. if its warm it will backfire more.. if its cold it wont backfire.... but then again i take it easier when its not warmed up.

Yep, that's EXACTLY how mine is. I can keep it from doing it with a little skinny pedal finess.  :D
I am missing a manifold stud on the rear. Hmmm we have a lot in common

[chardrc]

i havent driven my jeep forawhile cuz my taqillights totaly rusted out and i dont want to get a ticket so im driving my bros s10.. hopefully i can drive my jeep soon and start trying to fix that backfire since i fixed my gasleak (neer the exzost:shock: ) which i thought was more important thatn backfire...

[kenny kustom]

mine started to backfire after i hit the downpipe from the exhaust on some rocks really hard... had the downpipe replaced and he made me a new flange that meets the header. try having a larger flange made...now sounds great and no backfire  :D