Backfiring 2.5L - Page 3 - JeepForum.com

Reply
 
LinkBack Thread Tools
post #31 of 42 Old 11-20-2009, 09:15 AM Thread Starter
RebuildRookie
Registered User
1988 YJ Wrangler 
 
Join Date: Jun 2009
Location: Central Mississippi
Posts: 852
Alright, last night I swapped the air box hose to exhaust manifold around. Bad end on air box and better end on exhaust manifold.

2 days ago I did the "Seafoam" treatment, and runs better than ever. Got to work this morning and no "Poof". dont know if it was a fluke or not.

I ran the seafoam, because I got to thinking: Backfiring is caused by gas vapors that make it to the exhaust and ignite, what if the super rich running problem I had before I started working on it, created alot of buildup in the cylinders and it wasnt burning the fuel properly or fully.

Gonna keep monitoring it.


I'm a more proactive person.
You spray the ants before they get in your house.
You plant the crops before you starve.
And you keep the terrorists in check before you get your *** blowed off.
RebuildRookie is offline  
Sponsored Links
Advertisement
 
post #32 of 42 Old 11-20-2009, 10:51 AM
5.7YJ
Senior Member
 
5.7YJ's Avatar
1987 YJ Wrangler 
 
Join Date: Aug 2006
Location: Rockledge
Posts: 912
Good to hear you didn't get a POOF today! Hope it stays that way for you!
5.7YJ is offline  
post #33 of 42 Old 11-20-2009, 11:22 AM
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit
Posts: 22,863
oh come on RR. tell the truth. You just went light on the Chilli and Beer last night. No more Poofing...
Glad to hear things are riding well on the heep. Did you ever take a look for leaking around the intake egr?
Que89YJ is offline  
post #34 of 42 Old 11-20-2009, 11:25 AM Thread Starter
RebuildRookie
Registered User
1988 YJ Wrangler 
 
Join Date: Jun 2009
Location: Central Mississippi
Posts: 852
Chili maybe, but beer no way.


I did look and realized that the intake side was good, but where the tube goes into the exhaust manifold right above the O2 sensor, there is no gasket, must have forgotten to put it in for some reason. Thinking about putting som RTV on it.

Wondering where you've been lately, didnt know if you where sick or something. I realize why you go to that part of TN. We had a blast and it was beautiful. My buddy took his 92 YJ and went riding a little. We stayed at the Natchez Trace State Park in Wildersville/Lexington TN.

I'm a more proactive person.
You spray the ants before they get in your house.
You plant the crops before you starve.
And you keep the terrorists in check before you get your *** blowed off.
RebuildRookie is offline  
post #35 of 42 Old 11-20-2009, 01:04 PM
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit
Posts: 22,863
Honey do's and honey don'ts if you know what I mean. Work is begining to pick up too, so I actually have to do some real tech work during the day. I have relatives and friends al over the place in Tennesse. I mainly stay on the east side Pidgeon Forge area. I love it in Tenn. there are so many beautiful places to play. With no gasket your going to have a difficult time sealing it. I hate to say it because I know what a pain it is dealing with those 2 bolts for the egr tube but you might be better off pulling them and getting a gasket in there. That tube gets so hot that I think any rtv will not hold even the high temp stuff.
Que89YJ is offline  
post #36 of 42 Old 11-20-2009, 01:19 PM Thread Starter
RebuildRookie
Registered User
1988 YJ Wrangler 
 
Join Date: Jun 2009
Location: Central Mississippi
Posts: 852
I was thinking the same thing with the RTV. Taking the bottom of the tube isnt so bad now, I have a 12" extension and there are 2 spots by the powersteering pump that I can get to it real easy. But still no fun.

Just got back from meeting the wife for lunch. On the way I putted along at around 55 and when I got there no "Poof". On the way back to work got it up to 70 and was on it hard, parked it and got a "Poof". Seems like for some reason when i'm on it hard it does it.

I'm a more proactive person.
You spray the ants before they get in your house.
You plant the crops before you starve.
And you keep the terrorists in check before you get your *** blowed off.
RebuildRookie is offline  
post #37 of 42 Old 02-08-2010, 11:04 PM
SDGBASSE
Registered User
1990 YJ Wrangler 
 
Join Date: Jul 2009
Location: Mtl, Qc
Posts: 650
Any new input on this? I'm getting the same thing on mine. How's your idle, mine's horrible, it goes to 1800 RPMs at operating temp. And how were your spark plugs, I think it's backfiring on mine because my #4 plug is lead-fouled, and when I shut the engine off the deposits are hot enough to ignite what may be left of vapors in the cylinder. And I'm running a bit lean, since my plugs are whiteish.

Quote:
Originally Posted by ZeroGravity View Post
I didn't click the link because it says "power probe" in the url.
SDGBASSE is offline  
post #38 of 42 Old 02-19-2010, 07:40 PM
SamzJeep
Member
 
SamzJeep's Avatar
1988 YJ Wrangler 
 
Join Date: Jan 2007
Location: arizona
Posts: 425
Hey SDGBASSE.....mine was doing pretty much the same thing too. I did find that pretty much most of my vacuum lines were bad (even those four little ones on the side of the throttlebody). Afer I replaced all of my vacuum lines, my idle went down to about 1200 rpms and she runs really well. I am still getting a slight backfire after I've driven it home from work (30 minutes on the freeway). I've replace my cat, muffler, fuel injector (inside the throttlebody), exhaust manifold (it was cracked and leaking bad), spark plugs, plug wires, 02 sensor, and that's pretty much it. I thought the cat was bad, but that didn't do anything. I recently failed my emissions test (Maricopa County, Arizona) because they said it was running rich. I'm going to see if I can pass tomorrow morning because I just fixed the vacuum leaks this week. If it doesn't pass/runs rich, I'm going to see about changing that CTS (whatever that is). But, I'd say yours may be a vacuum leak, because that's what was causing mine to idle so high. Hope this helps....

SUPPORT OUR TROOPS
SamzJeep is offline  
post #39 of 42 Old 04-08-2010, 08:59 AM Thread Starter
RebuildRookie
Registered User
1988 YJ Wrangler 
 
Join Date: Jun 2009
Location: Central Mississippi
Posts: 852
Alright its been a while, but I finally got it to quite backfiring. Vacuum leaks, vacuum leaks, vacuum leaks, I kept tracking them down and finally got all of them fixed. Hasnt back fired in a couple weeks or poofed in a couple of weeks.

I'm a more proactive person.
You spray the ants before they get in your house.
You plant the crops before you starve.
And you keep the terrorists in check before you get your *** blowed off.
RebuildRookie is offline  
post #40 of 42 Old 04-08-2010, 09:37 AM
Que89YJ
Web Wheeler
1989 YJ Wrangler 
 
Join Date: Apr 2008
Location: Detroit
Posts: 22,863
No beer???? Come on RR. LOL Did you put the gasket in the EGR tube or did you just cap it off?
Que89YJ is offline  
post #41 of 42 Old 04-08-2010, 11:20 AM Thread Starter
RebuildRookie
Registered User
1988 YJ Wrangler 
 
Join Date: Jun 2009
Location: Central Mississippi
Posts: 852
Plenty of Beer to tell the truth. Sometimes a 6 pack or 2 just looking at the engine with the hood proped, thinking about what could be wrong, without actually touching anything. haha

RTV'd the EGR Tube.

I'm a more proactive person.
You spray the ants before they get in your house.
You plant the crops before you starve.
And you keep the terrorists in check before you get your *** blowed off.
RebuildRookie is offline  
post #42 of 42 Old 04-08-2010, 11:34 AM
bharris68
Senior Member
1989 YJ Wrangler 
 
Join Date: Jun 2006
Location: Issaquah
Posts: 994
I think that the key here is that the 2.5L in 89 & presumably 88 were TBI and controlled by a pretty accurate computer.

Mine runs like a Swiss Watch even after 21 years. If you start testing your voltages via the underhood ports: Passenger side, just under the hinge and above the battery, you'll likely find your culprit. My vote is 02 sensor will be off, causing you to run rich. It may also be that you've got a clogged Vacuum line, in which case, blowing them out or siphoning seafoam into the system will clean them out.

The tube that comes off the exhaust manifold to the air cleaner box tells the PCM that the engine is warm. Check to make sure that vacuum line is cleaned out. Again - my vote is 02 sensor - unless you put a new Bosch sensor on there AND there is voltage getting to the PCM, you're probably going to run rich.
bharris68 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
2.5L backfiring MooseMarine YJ Wrangler Technical Forum 3 07-27-2009 11:45 AM
backfiring? greenmanalishi YJ Wrangler Technical Forum 2 06-25-2009 01:06 PM
Backfiring TJ kmj153 TJ Wrangler Technical Forum 4 02-12-2008 02:39 AM
Backfiring? tjbrotha TJ Wrangler Technical Forum 5 07-01-2006 11:26 AM
Backfiring 4x4chef YJ Wrangler Technical Forum 1 05-12-2006 10:03 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome