Misfire code won't go away? WTF? - Honda-Tech

Go Back   > >
Log In 


Misfire code won't go away? WTF?

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 07-29-2010, 09:17 PM   #1
Honda-Tech Member
Thread Starter
 
Speed Kills's Avatar
 
Join Date: Jun 2006
Location: Cincinnati, OH, USA
Posts: 119
Default Misfire code won't go away? WTF?

2000 CRV, B20/5 speed.


Came in with a random misfire code, sputtering, definitely not running properly. Fresh plugs and wires, no difference in how it runs. New Distributor, still throws code, sputtering gone, clear code, code still returns. Put the old distributor back on, now runs, throws code for different cylinder misfire.


We've cleared the code multiple times, and it stays off at idle no matter how long you let it idle, but comes back on after application of throttle.


This is boggling me. I've never seen one do this. Any insight?
Speed Kills is offline   Reply With Quote
Old 07-29-2010, 10:02 PM   #2
Honda-Tech Member
 
eghatch4sale's Avatar
 
Join Date: Mar 2004
Location: cleveland, ohio
Posts: 3,214
Default Re: Misfire code won't go away? WTF?

Bad valve ..... How much do u wnt for it ?
eghatch4sale is offline   Reply With Quote
Old 07-30-2010, 05:10 AM   #3
Honda-Tech Member
Thread Starter
 
Speed Kills's Avatar
 
Join Date: Jun 2006
Location: Cincinnati, OH, USA
Posts: 119
Default Re: Misfire code won't go away? WTF?

Funny....it's not mine anyways. Haha.

It runs 100% perfect now. For some reason just keeps throwing the Cyl. 4 misfire code upon driving it/revving the engine.
Speed Kills is offline   Reply With Quote
Old 07-30-2010, 10:10 AM   #4
HT Order of Merit
 
JDM_Ej's Avatar
 
Join Date: Aug 2004
Location: Bethel, CT
Posts: 6,196
Default Re: Misfire code won't go away? WTF?

Common problem... the valves were not adjusted properly and they become too tight and recess into the head, which causes the misfire.

How many miles on it? You can try a valve adjustment, but you will likely have to replace the head.
JDM_Ej is offline   Reply With Quote
Old 07-30-2010, 10:24 AM   #5
Honda-Tech Member
Thread Starter
 
Speed Kills's Avatar
 
Join Date: Jun 2006
Location: Cincinnati, OH, USA
Posts: 119
Default Re: Misfire code won't go away? WTF?

176K, as far as I know, it's never had a valve adjustment, unless it was done with the T-belt, which we did not do.

It doesn't miss anymore. It's still picking up a misfire code for some reason after it runs perfectly fine.

I highly doubt something is fouled up with the head. The compression/leakdown was perfect, and it's not missing right now, at all. It came in having a steady miss that progressively got worse over time that a distributor cleared up, but It still has a misfire code. The "bad valve" theory does not explain the miss being cleared up. It points to something in the ignition system, and I'd think the comp/leakdown would be enough to squash that theory as well.

If there was "something wrong with the valves" to cause it to have a misfire, it most certainly should show up in the compression/leakdown test. So now I'm extremely confused.
Speed Kills is offline   Reply With Quote
Old 08-01-2010, 06:25 PM   #6
HT Order of Merit
 
JDM_Ej's Avatar
 
Join Date: Aug 2004
Location: Bethel, CT
Posts: 6,196
Default Re: Misfire code won't go away? WTF?

I agree with you there. It wouldn't get better if it was the valve/head issue, it would get progressively worse.

Hope you find the fix!
JDM_Ej is offline   Reply With Quote
Old 08-02-2010, 10:25 PM   #7
Honda-Tech Member
 
Duane_in_Japan's Avatar
 
Join Date: Jun 2005
Location: Tachikawa Shi, Tokyo, Japan
Posts: 2,294
Default Re: Misfire code won't go away? WTF?

You need scan data to monitor what is going on OR hook up a portable oscilloscope and a technician who knows how to read spark lines can tell what is going on inside the engine based on the heartbeat of the spark plugs. If you know what to look for you can see mechanical problems, injector problems, spark delivery problems, compression and timing problems, or look at the sensors that would report the misfire (CKP, CMP) and see what kind of signal are they producing and what is the amplitude in case the sensor is misadjusted.

What is the MAP sensor voltage going back to the ECM at a fully warmed up idle with no accessories on, should be just a hair under 1V DC, use a digital multimeter to test. Above or below this means you need to clean the throttlebody, IACV, recheck and if still not in spec, do a valve adjustment.
Duane_in_Japan is offline   Reply With Quote
Old 08-14-2010, 10:40 AM   #8
Honda-Tech Member
 
raidacaipo's Avatar
 
Join Date: May 2008
Location: CA
Posts: 3,580
Default Re: Misfire code won't go away? WTF?

Quote:
Originally Posted by JDM_Ej View Post
I agree with you there. It wouldn't get better if it was the valve/head issue, it would get progressively worse.

Hope you find the fix!
Sometimes the check engine light goes away but its temporary. Trust me he needs to replace the head or replace the valves. This also happened to my CRV b20z2. I also got random misfire codes. After changing the spark plug wires, spark plugs, distributor, cleaning the fuel injectors and tried doing valve adjustment the motor starting dying slowly. It was so bad to the point where the whole car started to shake everytime I turn it on. I couldn't even adjust 3 of the exhaust valves cuz my filler gauge wouldn't go in between. Then I decided to replace the head and I found out that the valves were so bad on 3 cylinders. Also the headgasket was bad. Just 3 days ago I replaced it with a new head gasket and a p8r head and it runs perfect! no check engine lights either.

ADVICE! REPLACE THE HEAD REGARDLESS OF WHAT YOU SAY!

Problems - Bad headgasket, burnt valves

*note - B20 heads are notorious for giving out when you don't adjust the valves. From research, the valves should be adjusted every 30,0000 miles and not just "adjust only if noisy" as stated by the manual. You said the valves has never been adjusted and after 176k miles? I'd say your valves are definitely gone.. regardless of the compression/leakdown test you did.

If you really want to find out, remove the head and inspect it.
raidacaipo is offline   Reply With Quote
Old 08-14-2010, 09:59 PM   #9
Honda-Tech Member
 
Duane_in_Japan's Avatar
 
Join Date: Jun 2005
Location: Tachikawa Shi, Tokyo, Japan
Posts: 2,294
Default Re: Misfire code won't go away? WTF?

A compression test or leak down test will not show sunk valves, they are still seating good but the overall lift and duration are affected lowering the HP of the engine overall. This should be noticable while the engine is running while monitoring a vacuum gauge. A good technician can also see low vacuum on the Spark Line while viewing spark on an oscilloscope. It takes some good training to see mechanical problems via the spark line on the Oscope. I also believe that the MAP sensor output voltage will be affected since it is directly proportional to vacuum, thus affecting fuel delivery thus affecting, well, you see what I mean.
Duane_in_Japan is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
2001 accord stalled while driving, now won't start bagpiper22 Honda Accord (1990 - 2002) 9 07-14-2015 05:33 PM
03 Accord P0301 misfire eyez Honda Accord & Crosstour (2003 - Current) 6 08-29-2014 06:50 AM
P1336, P1337 recurring codes darkstormcr Acura Integra 4 11-28-2011 02:24 PM
90 accord, random sputtering and code 43 runderwo Honda Accord (1990 - 2002) 14 09-26-2011 07:29 AM
2001 LS (B18B1) STILL misfiring, please help. Gage™ Acura Integra 8 01-19-2011 03:28 PM


Tags
adjustment, code, crv, cylinder, element, engine, fit, honda, job, misfire, odessey, odyssey, ruckus, throwing, valve

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not 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 On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 03:46 PM.



Honda and the Honda marquee are registered trademarks of the American Honda Motor Company, Inc. Neither American Honda Motor Company nor its subsidiaries or affiliates shall bear any responsibility for Honda-Tech.com content, comments, or advertising. Honda-Tech.com is not affiliated with American Honda Motor Company in any way. American Honda Motor Company does not sponsor, support, or endorse Honda-Tech.com in any way. Copyright/trademark/sales mark infringements are not intended or implied.