1997 Landrover Discovery - 4.0L Skips 2.5 sec FIXED
-
- 400 Club: Mega-Star Contributor
- Posts: 481
- Joined: Thu Sep 23, 2010 8:48 am
- Location: greenville sc
1997 Landrover Discovery - 4.0L Skips 2.5 sec FIXED
Hey everyone. I have a 1997 Landrover discovery se7, 4.0 8cyl here at the shop. came in a few months ago with engine misfire, plugs were very worn. Replaced plugs and it ran great for a month, came back with int skip. Changed plugs again figuring defect and it ran great for a month. came back with an int skip again, did plugs again, had no time to play, and ran great again. Now its back and am not gonna bandaid again.
Our modis has no landrover program till end of week so I don't have much to work with. have changed all 4 ign coils and no help. have changed ign wires and no help. had a p1313, and p1316 bk "A" poss cat damage. When cold it runs great for 15-20 miles then skips on and off with precise timing, skips for 2.5 sec then great for 2.5 sec, back and forth. Throttle position or eng load not a factor, can even feel it when decelerating. When ideling or brake torque, will not misfire so can't isolate which cyl only bank "A" .
Hoping one of you magicians can offer some help.
Our modis has no landrover program till end of week so I don't have much to work with. have changed all 4 ign coils and no help. have changed ign wires and no help. had a p1313, and p1316 bk "A" poss cat damage. When cold it runs great for 15-20 miles then skips on and off with precise timing, skips for 2.5 sec then great for 2.5 sec, back and forth. Throttle position or eng load not a factor, can even feel it when decelerating. When ideling or brake torque, will not misfire so can't isolate which cyl only bank "A" .
Hoping one of you magicians can offer some help.
Last edited by jbadenoch on Thu Jun 23, 2011 6:55 am, edited 2 times in total.
- steven kiser
- 5K Holy Smokes Contributor
- Posts: 6184
- Joined: Fri Jul 06, 2007 4:58 am
- Location: eastern ma.
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
sounds like a bad cam or crank sensor
never argue with a fool, they'll drag you down to their level and beat you with experience
-
- 400 Club: Mega-Star Contributor
- Posts: 481
- Joined: Thu Sep 23, 2010 8:48 am
- Location: greenville sc
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
was thinking of trying it any way. I'll let ya know as soon as I do.
-
- 400 Club: Mega-Star Contributor
- Posts: 481
- Joined: Thu Sep 23, 2010 8:48 am
- Location: greenville sc
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
good tuesday morning to ya'll. I see not too many bites on this one. going to scope crank sensor and cam sensor today, i'll let ya know.
-
- 400 Club: Mega-Star Contributor
- Posts: 481
- Joined: Thu Sep 23, 2010 8:48 am
- Location: greenville sc
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
crank and cam sensors scoped ok. changed anyway, no help.
-
- 2.5K Uber Ninja Contributor
- Posts: 2642
- Joined: Wed Feb 04, 2009 1:28 pm
- Location: PA
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
I'm not surprised. My first thought as I read the initial post was possibly faulty ignition wires, possible ground issue, or possibly a PCM issue. Even possibly a lean running engine that overworks the secondary ignition system. What are fuel trim values? Also, what is the voltage coming to the ignition coil(s)? That needs to be battery voltage. But beings this is a firing setup where two plugs fire at the same time, my gut feeling is that in the secondary ignition is where the problem is.jbadenoch wrote:crank and cam sensors scoped ok. changed anyway, no help.
-
- 400 Club: Mega-Star Contributor
- Posts: 481
- Joined: Thu Sep 23, 2010 8:48 am
- Location: greenville sc
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
voltage to coils is equal to battery voltage. s fuel trim from +24 - neg 3 bank 1. bk 2 almost identical even when misfiring. LT both banks hanging around +3 even when misfiring. ???? fuel pressure 30 psi at idle, 40 psi on accel. changed plugs again at end of day and this time it didn't fix like the last 3 times? Landrover update for modis coming friday, hopefully obd2 side of pcm info will help
- steven kiser
- 5K Holy Smokes Contributor
- Posts: 6184
- Joined: Fri Jul 06, 2007 4:58 am
- Location: eastern ma.
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
a few things here, the repetitive skip pattern has me a scratching my head a bit. the single biggest issue i've had with these is exhaust valve's sticking. land rover has a redesigned exhaust valve but i replace the heads. there are a few ignition issues that cause intermittent skips but you've seemed to have covered them. can you identify which cylinders are causing the misfire by the condition of the plugs? there is a tech bulletin that instructs you on attaching and reading a vac gauge to check for a valve issue. the top ends of these engines are crapolla. good luck.
never argue with a fool, they'll drag you down to their level and beat you with experience
-
- 400 Club: Mega-Star Contributor
- Posts: 481
- Joined: Thu Sep 23, 2010 8:48 am
- Location: greenville sc
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
I appreciate some of the insight on this **** box, but it's going to the dealer, (last place i want to send anyone) and the customer will let us know what the fix was then I'll post it for ya. Once again, thanks for the insight.
- steven kiser
- 5K Holy Smokes Contributor
- Posts: 6184
- Joined: Fri Jul 06, 2007 4:58 am
- Location: eastern ma.
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
sometimes it's best to send it to the dealer. unfortunately the dealer is going to throw you under the bus.
never argue with a fool, they'll drag you down to their level and beat you with experience
-
- 400 Club: Mega-Star Contributor
- Posts: 481
- Joined: Thu Sep 23, 2010 8:48 am
- Location: greenville sc
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
as long as its not the short bus.
- fortknoxx
- 1500 Club Master Plus Contributor
- Posts: 1873
- Joined: Wed Sep 13, 2006 6:09 am
- Location: High Point, NC
- Contact:
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
put your helmet on lil buddyjbadenoch wrote:as long as its not the short bus.
T-N-T (Tina Nuse-Tolar)
Gone but not forgotten...Camper Bob's
609-760-7079 Cell
Gone but not forgotten...Camper Bob's
609-760-7079 Cell
- timbre4
- System Guru / Moderator
- Posts: 4460
- Joined: Tue May 25, 2004 5:47 pm
- Location: TN - Volunteer State
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
Tim McDonnell -
Sr. Product Market Mgr / Forum Moderator / Mitchell 1 Media Developer
Sr. Product Market Mgr / Forum Moderator / Mitchell 1 Media Developer
-
- 400 Club: Mega-Star Contributor
- Posts: 481
- Joined: Thu Sep 23, 2010 8:48 am
- Location: greenville sc
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
sent this one to dealer and have not heard back about what the fix was. thanks to all who helped. Bob in sc
-
- 400 Club: Mega-Star Contributor
- Posts: 481
- Joined: Thu Sep 23, 2010 8:48 am
- Location: greenville sc
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
Dealer doesnt know either, throwing parts at it
- liljoe
- 1500 Club Master Plus Contributor
- Posts: 1636
- Joined: Thu Sep 21, 2006 6:27 am
- Location: Mentally: outer space. Physically: Alabama
- Contact:
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
If they find the problem I would like to know what it was, I just bought a nice forrest green one of these, seems like a neat truck....
Working hard to prove the Green Team can do it with the best of 'em.
Always remember: AIN'T NO FREE LUNCHES!!
Am I the Only One?- I don't think I am.
The further a society retreats from the truth, the more it hates those who speak it. George Orwell.
Always remember: AIN'T NO FREE LUNCHES!!
Am I the Only One?- I don't think I am.
The further a society retreats from the truth, the more it hates those who speak it. George Orwell.
- steven kiser
- 5K Holy Smokes Contributor
- Posts: 6184
- Joined: Fri Jul 06, 2007 4:58 am
- Location: eastern ma.
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
i don't know why i didn't hit on this at the beginning but are you using anti seize on the plug? i've run into issues like this before. not on this particular vehicle, but on more than just one or two. the anti seize will force loss of ground. i'm still a bit confused about the consistency of the skip. with patterns like this i usually find it's hitting during an emission test. if the fuel lines were somehow crossed and it was calling for an evap test raw gas may being introduced into the system and after a while will knock out a plug. there may be more than one contributing factor causing the end result. i would look into the anti seize as well as possibly shutting down all vac feeds from or to the engine and see what happens. watch the scanner while this is happening. see if any valve is being switched as well as the timing or high knock signal. on rereading the initial post the issue was a constant skip now we have a times intermittent. are we possibly getting a transmission shutter confused as a skip. i know it's a stretch and i'm not questioning anyone's ability but i've assumed that the issue at hand was the one from before and have been wrong. what happens if you drive it in third gear avoiding the converter trying to lock up. again, just throwing something out there to look at. sometimes this kicks me out of a locked thought process and i see it at a different angle.
never argue with a fool, they'll drag you down to their level and beat you with experience
-
- 400 Club: Mega-Star Contributor
- Posts: 481
- Joined: Thu Sep 23, 2010 8:48 am
- Location: greenville sc
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
lil joe, i'll certainly let you know prognosis as soon as i hear. steve, definately not trans related but you've got me thinking on the comp running emission tests. I only wish the vehicle was still here, we now have lr program for modis. only thing is changing plugs fixes problem for about a month? I suppose excess fuel could be slowly degrading plug. Really hope the dealer can definitively say which part they are tossing at it actually fixes it. yall have a great weekend, i'll keep you up to date. Bob in sc
-
- 400 Club: Mega-Star Contributor
- Posts: 481
- Joined: Thu Sep 23, 2010 8:48 am
- Location: greenville sc
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
rth. trying to fix time stamp, succeded. rth was just to post and see
Last edited by jbadenoch on Thu May 19, 2011 12:34 pm, edited 1 time in total.
- liljoe
- 1500 Club Master Plus Contributor
- Posts: 1636
- Joined: Thu Sep 21, 2006 6:27 am
- Location: Mentally: outer space. Physically: Alabama
- Contact:
Re: 1997 Landrover Discovery - 4.0L Skips 2.5 sec
????jbadenoch wrote:rth
Working hard to prove the Green Team can do it with the best of 'em.
Always remember: AIN'T NO FREE LUNCHES!!
Am I the Only One?- I don't think I am.
The further a society retreats from the truth, the more it hates those who speak it. George Orwell.
Always remember: AIN'T NO FREE LUNCHES!!
Am I the Only One?- I don't think I am.
The further a society retreats from the truth, the more it hates those who speak it. George Orwell.