Uneven idle

Technical questions and answers about the Mazda Bongo

Moderators: Doone, westonwarrior

Post Reply
mixers123
Apprentice Bongonaut
Posts: 9
Joined: Sun Apr 17, 2016 8:33 pm

Uneven idle

Post by mixers123 » Fri Jun 07, 2019 9:10 pm

2002 petrol 2l
When engine warms up idle speed fluctuates to the point of cutting out.

Any help would be much appreciated ....thanks
User avatar
g8dhe
Supreme Being
Posts: 10180
Joined: Sun Apr 13, 2008 10:06 pm
Location: Worthing, West Sussex.
Contact:

Re: Uneven idle

Post by g8dhe » Fri Jun 07, 2019 9:50 pm

Could be several reasons but distributor arm, cap, leads and also fuel and air filters can also be the cause.
Geoff
2001 Aero V6, AFT, full side conversion.
Image Spherical Visions
Flanners
Bongolier
Posts: 421
Joined: Tue Oct 31, 2017 4:11 pm

Re: Uneven idle

Post by Flanners » Sat Jun 08, 2019 8:27 am

Had this on my 2.0L someone had previously messed about with screw at the bottom of the TB which alters the air fuel mixture and should not be touched, there are posts on here documenting how to sort it by 'locking out the ecu' while adjusting the revs with the screw. Failing that possible vacumn leak or oil/carbon deposits in the TB/butterfly, can be cleaned out. Check the accelerator cable is not sticking and has some 'slack' to allow the TB to close etc.
2002 2.0 Aero with Outback Conversion and Roof Top Tent
teenmal
Supreme Being
Posts: 3656
Joined: Thu Mar 27, 2008 6:08 pm
Location: north lanarkshire

Re: Uneven idle

Post by teenmal » Sat Jun 08, 2019 9:10 am

Always worth checking the air clack vale in the fuel cap, or try the vehicle with the cap off or really loose.
User avatar
mikeonb4c
Supreme Being
Posts: 22871
Joined: Sun Nov 05, 2006 10:49 pm
Location: Living with Mango Bongo in the North West but with a tendency to roam
Contact:

Re: Uneven idle

Post by mikeonb4c » Sat Jun 08, 2019 9:44 am

Flanners wrote: Sat Jun 08, 2019 8:27 am Had this on my 2.0L someone had previously messed about with screw at the bottom of the TB which alters the air fuel mixture and should not be touched, there are posts on here documenting how to sort it by 'locking out the ecu' while adjusting the revs with the screw. Failing that possible vacumn leak or oil/carbon deposits in the TB/butterfly, can be cleaned out. Check the accelerator cable is not sticking and has some 'slack' to allow the TB to close etc.
In case its needed, is this the relevant post?

viewtopic.php?f=3&t=73643

What is a TB btw - been racking my brain cell to no avail :lol:
Flanners
Bongolier
Posts: 421
Joined: Tue Oct 31, 2017 4:11 pm

Re: Uneven idle

Post by Flanners » Sat Jun 08, 2019 10:25 am

TB is the Throttle Body :D Yes that is the post, good searching!
2002 2.0 Aero with Outback Conversion and Roof Top Tent
mixers123
Apprentice Bongonaut
Posts: 9
Joined: Sun Apr 17, 2016 8:33 pm

Re: Uneven idle

Post by mixers123 » Sat Jun 08, 2019 7:34 pm

Throttle body has been changed ,
did find 1 spark plug loose and HT lead going to that plug very hot , hotter than the other 3
, also recently fitted K&N air filter .
Flanners
Bongolier
Posts: 421
Joined: Tue Oct 31, 2017 4:11 pm

Re: Uneven idle

Post by Flanners » Sun Jun 09, 2019 11:57 am

Why was the TB changed, was this changed in the quest for stabilising the revs?
2002 2.0 Aero with Outback Conversion and Roof Top Tent
Flanners
Bongolier
Posts: 421
Joined: Tue Oct 31, 2017 4:11 pm

Re: Uneven idle

Post by Flanners » Sun Jun 09, 2019 12:06 pm

teenmal wrote: Sat Jun 08, 2019 9:10 am Always worth checking the air clack vale in the fuel cap, or try the vehicle with the cap off or really loose.

That is sound advice and helped mine no end

Clarification thread from 2012:
viewtopic.php?t=55369
2002 2.0 Aero with Outback Conversion and Roof Top Tent
mixers123
Apprentice Bongonaut
Posts: 9
Joined: Sun Apr 17, 2016 8:33 pm

Re: Uneven idle

Post by mixers123 » Sun Jun 09, 2019 2:36 pm

Yes throttle body was changed to try and solve this problem
So far TB changed
Plugs tightened
Awaiting HT leads
District & rotor arm changed
K&N removed original air filter back in
Petrol cap loosened
As I said only when warm almost to the exact 10mins idling
Post Reply

Return to “Techie Stuff”