Discovery II Talk about the Land Rover Discovery II within.
Sponsored by:
Sponsored by:

Misfire under load!

Thread Tools
 
Search this Thread
 
Old Jul 31, 2011 | 03:43 AM
  #1  
Aggrov8's Avatar
Thread Starter
|
3rd Gear
Joined: Jul 2011
Posts: 3
Likes: 0
Cool Misfire under load!

Can someone help me get my sanity back!!!

To cut a long story short we cooked our disco and two engines later have sorted the temp problem but have a misfire problem.

No faults or anything coming up on testbook. new ht leads, new coil packs, new plugs, new alternator, new battery, new air flow meter. Still runs well along flat or downhill, but as soon as load is needed she farts like a trooper.

Something whcih we noticed yesterday - on cylinders 1,2, and 5 if we remove a ht lead while engine is hot and running the spark jumps about 25mm to an exhaust stud, a lovely strong spark. On the other cylinders we dont get the jump, but we can here it cracking nicely when practically touching the exhaust stud.

Are cylinders 1,2,5 exceptionaly strong spark and the others normal - or are 1,2,5 normal and the rest weak.

Can someone try their car for me or give some indication of what i should get.

Cheers guys this has been ******* me for about a year now.
 
Reply
Old Jul 31, 2011 | 07:59 AM
  #2  
Disco Mike's Avatar
Administrator
Joined: Apr 2006
Posts: 25,707
Likes: 107
From: Denver, Colorado
Default

Spark is equal to all cylinders.
 
Reply
Old Jul 31, 2011 | 08:26 AM
  #3  
Savannah Buzz's Avatar
Super Moderator
Joined: Jan 2011
Posts: 16,322
Likes: 88
From: Savannah Georgia
Default

ECU problem? Seems like something must control spark advance. See pix of a scanner monitoring real time data, that one at the bottom should change, as do many of the others, under changing loads. If you have or can borrow a scanner, have co pilot write down readings from several things while you hold the vehicle at various speeds and loads. Almost as dangerous as texting while driving. Might point to something, like sensor ECU uses to determine camshaft position, etc. Ignition items are covered in detail in the electrical troubleshooting guide of the RAVE.

BTW, how about sharing your info on overheating and slow roasting two engines over mequite coals?
 
Attached Thumbnails Misfire under load!-p1030591.jpg  
Reply
Old Jul 31, 2011 | 08:54 AM
  #4  
Disco Mike's Avatar
Administrator
Joined: Apr 2006
Posts: 25,707
Likes: 107
From: Denver, Colorado
Default

Who's MAF are you using, did it have matching part numbers with the original one.
Do a compression test and get back to us with the numbers.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
DiscoNDixie
Discovery II
2
Mar 8, 2011 05:36 AM
turboedws6ta
Discovery II
7
Feb 3, 2009 09:23 AM
jcostello
General Tech Help
14
Feb 20, 2007 07:18 PM
jcostello
Discovery II
4
Oct 27, 2006 03:39 PM
Taipan
Freelander
0
Oct 15, 2006 02:52 PM




All times are GMT -5. The time now is 01:59 AM.