High idle cold start in P, rough running idle. - Land Rover Forums : Land Rover and Range Rover Forum
LinkBack Thread Tools Display Modes
post #1 of 1 (permalink) Old 03-26-2019, 12:37 PM Thread Starter
Join Date: Mar 2017
Location: Victoria Canada
Posts: 57
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
High idle cold start in P, rough running idle.

Hey gang,

First things first, Codes: misfire on all cyls, and evap errors, I will be more specific when they come back, I cleared them by mistake.

I am trying to diagnose a weird idle issue. Initially I found that the truck (2003 D2 4.6 auto) would rev up to 2000rpm and hang there for like 10 seconds or so before dropping down to normal range. I replaced plugs removed IACV, cleaned and tested it, cleaned throttle body. I also found that the SAI pump was destroyed and the tube leading from it was full of gross water, probably from the pump housing being open and water getting in there.

After cleaning, replacing and testing components, the cold start will rev up to about 2000 and then drop down to 1200 a second later, two seconds after that it drops to 7-800ish. I think that's still too high and I don't like it.

Furthermore I have a rough idle when the engine is warm, it seems to be worst when I have it parked for a bit and kept it idling.

This is a project truck and is new to me, as such I am unfamiliar with how long its been like this. I have looked for vacuum leaks but I cant seem to find any. What should I be looking for at this point?

Here is some data from my Hawkeye:
Engine Rough Cyl 8: .74
Engine Rough Cyl 6: .60
Engine Rough Cyl 3: .31
Engine Rough Cyl 1: .49

others are 8

O2 sensor US A
O2 sensor US b
O2 sensor DS A
O2 sensor DS B

TPS seems to be working well, 0.00 on idle and about 78 WOT.
Hamhockracer is offline  
Sponsored Links

  Land Rover Forums : Land Rover and Range Rover Forum > Land Rover Model Forums > Discovery Series II

Quick Reply

Register Now

In order to be able to post messages on the Land Rover Forums : Land Rover and Range Rover Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

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


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Thread Thread Starter Forum Replies Last Post
98 Discovery power loss, high idle when cold p1447 and p0451. nissandon83 Discovery Series I 2 06-06-2019 03:00 PM
Very rough start when cold, fine when warm ian.laughlin Discovery Series II 4 05-30-2018 12:10 PM
Rough/Noisy Idle when cold D2 Hamhockracer Discovery Series II 5 03-01-2018 02:43 PM
2004 Range Rover - Rough Idle at Cold Start Noriskfreetrial Range Rover P38, Mk III and Range Rover Sport 9 04-19-2017 02:08 PM
Overheating, Code 25, rough rough idle DiscoBenny Range Rover Classic 4 08-28-2010 02:17 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 On
Pingbacks are On
Refbacks are On

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