Disco stalls when stopping or setting at redlight

Kellee

New member
Jun 21, 2019
4
0
Tennessee
For the past few months my 2002 Discovery with 4.0 will randomly either Stall while stopping or while setting in traffic. Other times the S&m light will start flashing and go into limp mode .
In past two months I have replaced battery with a yellow top, new MAF, replaced crankshaft position sensor twice , checked battery cables, replaced plugs and plug wires. Each time I replaced the CPS it ran perfect for a couple days then started doing same thing again.
If I set and let engine idle it will idle smooth at 750 for a while then rpm will have a slight change and stall or S& M lights will come on.
Any advuwhere to start.
I bought this disco new in 2002 and only have 98k on it. Looks new just currently unreliable.
 

Kellee

New member
Jun 21, 2019
4
0
Tennessee
Forgot to add that I also put a new fuel pump a few months ago at my previous mechanic diagnoses. Did not change anything.
 
Last edited:

bradartigue

Well-known member
Mar 7, 2018
112
17
Sandy Springs, Georgia
I assume by "S&M" light you mean the check engine light? "Service Engine Soon" or whatever it says. When it comes on, what code does it give you?

For example, when I got my 2000 it would throw some codes and die. Codes said the mixture was getting lean prior to it dying. Lean = too much air. Hunt for air leak. Found air leak at brake booster connection to plenum and unused air port beneath booster connection.
 

JUKE179r

Well-known member
Sep 14, 2016
761
95
Suffolkshire, UK
Each time I replaced the CPS it ran perfect for a couple days then started doing same thing again.
What brand of CPS did you buy? Get a Bosch and never a Duralast. I've had 2 brand new and but bad Duralasts from Auto Zone. The Bosch CPS fixed the problem.
Your S&M/M&S lights could be a myriad of electrical issues. Low battery/system voltage, bad alternator charging, XYZ switch bad...
What are you trouble/fault codes? Post them here.
 

Kellee

New member
Jun 21, 2019
4
0
Tennessee
I have bought one from Advance Auto and NAPA. I did just order one from Land Rover in Knoxville. $185 instead of $60. Installed it a week ago and now 600 miles later all is perfect. Even seems like better acceleration.
In this case I think the OEM part fixed the issue.
I’ll update if anything changes.
Thanks for reply
 

Swedjen2

Well-known member
Sep 12, 2018
594
127
California
For next time, 'cuz there will always be a "next time'", get a OBDII code reader off Amazon. There are several good ones for < $100. Bluedriver LSB2 (bluetooth- Highest rated - 4,700 reviewers can't be wrong), Foxwell NT301 or Autel Autolink.
There are cheap Battery and Alternator testers as well. Far, far better than some old voltmeter only suitable for a Model T.
 
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Kellee

New member
Jun 21, 2019
4
0
Tennessee
For next time, 'cuz there will always be a "next time'", get a OBDII code reader off Amazon. There are several good ones for < $100. Bluedriver LSB2 (bluetooth- Highest rated - 4,700 reviewers can't be wrong), Foxwell NT301 or Autel Autolink.
There are cheap Battery and Alternator testers as well. Far, far better than some old voltmeter only suitable for a Model T.
Took your advice. I just order an OBD II reader. I have never used one but if I’m going to keep driving my Discovery I’ll need to learn how .
Thanks for the advice.
 

Jkid

Active member
Dec 30, 2007
44
0
I would check for a vacuum leak and clean the throttle body real good if it’s dirty. The codes will help too
 

skucera

Member
May 13, 2014
5
0
Harrisburg, Oregon, USA
On any Bosch engine, my first instinct is to clean out and lube the idle control valve. That reminds me, I need to clean out the one on my wife's BMW before winter comes.

Scott