Rough idle at start
#1
![Default](/forum/images/icons/icon1.gif)
I have a 1981 XJ6 with fuel injection. It starts fine but idles rough and at about 400 to 500 rpm for 4 minutes then it goes to normal idle about 800 rpm and runs good. I can't believe it is the cold start injector it is always 90 degrees here. Any suggestions. Thanks,,,,,,Jerry
#2
Join Date: Mar 2008
Location: Pacific Northwest USA
Posts: 24,880
Received 10,936 Likes
on
7,185 Posts
![Default](/forum/images/icons/icon1.gif)
The 'could be' list might get long. Here are some starters
Might be.....
XJ 6 Series III 4.2 - Cold Start EFI Overfuelling
Might be that your AAV isn't working. This is what increases idle speed on a cold engine
Descripton and Function of Aux Air Valve, Series III XJ6
Might be that your coolant temp sensor is skewed. it plays a major role in fueling until coolant hits about 160ºF
Testing the Coolant Temp Sensor
Cheers
DD
Might be.....
XJ 6 Series III 4.2 - Cold Start EFI Overfuelling
Might be that your AAV isn't working. This is what increases idle speed on a cold engine
Descripton and Function of Aux Air Valve, Series III XJ6
Might be that your coolant temp sensor is skewed. it plays a major role in fueling until coolant hits about 160ºF
Testing the Coolant Temp Sensor
Cheers
DD
The following users liked this post:
Andy Paine (10-13-2018)
#3
#4
Join Date: Mar 2008
Location: Pacific Northwest USA
Posts: 24,880
Received 10,936 Likes
on
7,185 Posts
#6
Join Date: Jul 2012
Location: Walnut Creek, California
Posts: 6,796
Received 2,399 Likes
on
1,880 Posts
#7
![Default](/forum/images/icons/icon1.gif)
I checked the AAV as described and it is closed when cold and closed when it get up to temperature, I also checked the plug and it does have 12 volts when running. I guess it is bad. (enclosed are pictures with engine cold). I guess I should remove it and try to clean it. Is the 2 allen screws the only thing holding it to the water rail? Thanks for the help.....Jerry
Trending Topics
#8
Join Date: Mar 2008
Location: Pacific Northwest USA
Posts: 24,880
Received 10,936 Likes
on
7,185 Posts
#9
Thread
Thread Starter
Forum
Replies
Last Post
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)