Jaguar V12 Idle Issues - Checking AAV and adjusting idle - How to tune a Jaguar V12 Part 4

The Jaguar V12 AAV is prone to not work correctly after many years of service. In this 4th part of tuning a Jaguar V12 I show you how to test your auxiliary air valve (AAV) and how to set the idle.
Rebuild your AAV - Contact Jonas Loda: [e-mail]
How to Tune a Jaguar V12 playlist: • How to Tune a Jaguar V12
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Music used: Dancing Hearts - Anders Enger Jensen • Dancing Hearts
#jaguarv12 #jaguarxjs #jaguarxj12

[@reallymadmaso]

I just received a rebuilt AAV from Jonas Loda. The item is amazing. Can’t wait to install. His communication is amazing and I think his prices are very reasonable. Thanks for recommending him LWAC!

[@LivingWithAClassic]

Yes he’s a great guy!

[@charlessterling6850]

after watching your video I decided to check my AAV valve, and its not moving at all, this is the problem I have been chasing for years on my 88 XJS v12 has finally been solved, so thanks for your videos,I think your doing a great service to guys like me who want to fix everything myself.

[@LivingWithAClassic]

I'm really glad I could help!

[@getawayhs2856]

If there's a job to do on a Jag, you can bet Adam has done a video on it 😄 This channel is a great source of information.

[@klwthe3rd]

So basically it's like a thermostat for your idle air enrichment? Seems Jaguar by the 90's would have used an electronic method like other manufacturers. I also love how you prefer to have your items rebuilt so you can keep the original items on your car. It's so nice to see someone care enough to also share his resources for these restorations services with the community. God knows i would have never found Jonas on my own. Lol. Awesome explanation as always!

[@LivingWithAClassic]

Yes it is. One would think that too but they went with 60's and 70's technology. It is very reliable but off course after 40 years they do need attention. It's always a lot more fun to rebuild original items 😊

[@charliecalanni6032]

You are awesome. Clamped off the hose coming off the air cleaner and, oh look, it idles slower now..... Thanks very much.

[@AbramCalebTheOrganLoft]

I sent my AAV to Jonas from Georgia USA. It took about a week. When I get it back I hope I can get my Jag running. As mentioned before, it was backfiring and having idle issues.

[@workshop_deluxe2493]

Adam, thank you so much for this video. Previous owner of my XJ-S V12 replaced the valve and messed it up. Did even tighten the clamps. The idle is at 1500 and your videos help me to understand the principles. Tack så mycket. Christian

[@Millmiglia001]

Do what i did ,i got a hand held steamer and steam cleaned it .once it dried internally i spray in a little WD40 to lubricate it,put it back on and it idled perfectly smooth EXCELLENT

[@drewframson7495]

I just scored a used AAV on ebay for 20 dollars! I'm going to send it out to Jonas Loda for rebuild, and then swap out the one on my 91 XJS V12 Classic Collection Convertible. My current one works, but at 30 years old...why not!

[@LivingWithAClassic]

What a score! I do have a few extra ones also. You never know when you'll need a new one. My rebuilt one works very well now

[@BoudeM]

Yes that the one I have been waiting for, Thanks a lot Adam!

[@LivingWithAClassic]

You're welcome! Glad you enjoyed it

[@handsonprojects2137]

I took my old stuck one apart when it was seized and rebuilt it making it manual with a cable , spring and hand throttle of lawn mover type, it works very well

[@marcpollard8792]

Brilliant work mate Thankyou!

[@LivingWithAClassic]

Thanks for watching!

[@manuelcollazo-llantin5044]

Jonas Is awesome!

[@LivingWithAClassic]

He sure is!

[@stanlewis3158]

Thank you for the excellent video Adam, I am picking up a 1991 xjs v 12 I recently purchased. I am comfortable now attacking the high idle issue. I will have the AAV rebuilt if I check it and find it faulty. Please keep up the informative, detailed videos for us amateurs.

[@LivingWithAClassic]

Thank you for watching Stan! I hope a rebuilt AAV will fix your high idle issues

[@45H16E]

Nicely done, thanks. I'd add that the HE models also have a 45 second fast idle at start-up that is controlled by the ecu and separate from the AAV. It functions cold or hot regardless.

[@LivingWithAClassic]

Yes they do. I plan on showing that when I go through the vacuum lines on the HE. There's a lot of them! Thank you for watching

[@gc1914]

Thank you Adam making things so clear. A good friend of mine talked me into buying a 1990 xjs 12-cylinder classic collection convertible we were able to get it operable and I've been tinkering with it ever since I do enjoy the car immensely even though it just quit running the other day as I approached the stoplight . I had to have it towed home so my first thought was fuel second thought was maybe something electrical anyways you're videos are amazing and you're the reason I'm not going to ever sell the car you make things very clear so thank you. And right now I just use the car as an art piece just to stare at it. have an awesome day

[@LivingWithAClassic]

I'm really glad you enjoy them! Sounds like a great friend that talks you into buying an XJS. Let me know if you need any help

[@motorcyclementor1785]

I find the most common reason for the engine quitting is a bad connector on the front of the B Bank ( Drivers side n.america) water temp sensor. It's not the gauge sensor which is on the A bank but this one is for the ECU so that it knows the engine temp and the fuel mix. I've had two V12's and this has been a problem on both. Another slightly less common problem is the ignition module. I think the 1990 has a later system ( Minarelli) but the late eighties used a 1985 Chevy Blazer HEI module inside the box which is about 20 bucks froma Napa store. Third problem maybe a bad fuel pump. I'm just basing my answers on my own experiences but thee are common problem areas.

[@dwaynegraafland3812]

@@motorcyclementor1785 Would these solutions also work for a stalling Pre-HE V12 after starting the engine for the 2nd time when still warm?

[@motorcyclementor1785]

Mine was idling super fast when cold and causing bearing knock for the initial few seconds until the oil pressure built up which worried me a lot. Mine starts on virtually first compression stroke so no build up time. It was okay when hot so I knew it was the AAV, My short term and rather elegant solution was to remove the hose from AAV to intake manifold and stick a cork in there. I pushed a cotter pin through to stop it being sucked in completely and sealed it with silicone- worked like a charm. Just a whiff of throttle to start from cold. I'm looking at installing a 12 volt asco valve with a switch on the dash and some kind of air limiting orifice for when the valve is open. .

[@chadedwards2848]

Another great video Adam, thank you. I will have to pull the AAV on my ‘86 XJS, I think it is seized - it surges at idle whenever it is in park or neutral.

[@LivingWithAClassic]

Thank you Chad!

[@AbramCalebTheOrganLoft]

My car was surging as well

[@asdreww]

Great video. Need to pull mine off and check it at some point.

[@LivingWithAClassic]

Thank you for watching!

[@rossilake218]

Great video Adam. I want to get a spare and send to Jonas.

[@mustangmafiatv3660]

Hi adam i just put a new Gasket and hose on my Overrun Air valve on my 1983 Jaguar XJ6 series 3, before i changed them the car would idle at about 900rpm but since i've change them it is now idling at about 1000rpm how do i lower the rpm on my 1983 XJ6 Series 3 Thanks

[@ginatrup1]

Hi Adam , so glad for your videos, I have a 1 year rebuild AAV in my 1990 xjs v12, idles fine at start. After 25 min. drive my idle becomes erratic between 500 and 0. dies at every stop or park and requires a quick gas pedal to keep alive ,also my oil pressure by then shows barely 50. will check AAV, but think it is something else??

[@MrXlskywolf]

Good afternoon Adam, as a mention, working on my 92 XJS V 12 everything was mest up, spark plugs were @ .040 gaps, never change the 1A and 1B carburetor butterfly, bank A one was close completely, bank B was open to much, router was shot, that why I was running on six, one I fix everything, my idle was @ 3,000 thank you so much for your videos, they have been great for me, thanks

[@LivingWithAClassic]

I'm glad your car is running better now! Hope you can enjoy it on the road soon

[@MrXlskywolf]

O yes, and driving almost every day, my most surprised is corvette and BMW's looking at me, either they saying what a great car, or I'm crazy on maintenance this car

[@LivingWithAClassic]

I think they are admiring your car

[@MrXlskywolf]

ok now I know what to look for and test it, thanks

[@donx03]

Jolly Good

[@Lemuren77]

Great video! You are right, they are quite expensive. I replaced mine this summer. I'm quite novice and I had trouble to get it back in place again. Main reason was that I also replaced the hoses, they were harder and not much play/flex. Had to get the the AAV on the new sealing, in it place and both hoses "all at the same time" This was indeed tricky, but just needed to be patient and methodic :-) -87 Daimler DD6

[@LivingWithAClassic]

Thank you! I have sometimes removed the air box completely, it does make it a lot easier then. Is your new one working well?

[@Lemuren77]

@@LivingWithAClassic The new one is working well! Car starts easy and the idle is now set low and nice. I do however have a slighty rough idle, additional work do to :-)

[@LivingWithAClassic]

@@Lemuren77 The adventure continues!

[@drewframson7495]

Very simple, soak new hoses in very hot water to soften them to flex.

[@AbramCalebTheOrganLoft]

My AAV was frozen when I got the car. I soaked it in warm water for a couple of days and it started to work again. I squirted some light oil in it and it works. However, I want to send through the rebuild service anyway. My problem with my V12 is that when she idles, the engine runs smooth. When she warms up and I think the valve operates. The engine lopes. It will also randomly backfire when revved up. I think that I have two problems at one time: Timing and Vacuum issues.

[@johnsalster6313]

So, when you say heat the water to 80', is that C or F? My '88 xjs 5.3l idles a bit roughly when warmed up; could that be due to the AAV? Thanks.

[@meandthexj.2500]

I’ve just got a 1990 XJS V12 engine to Start. Last time it started was 2004. Found water coming out of the B bank air filter housing and in No. 2 cylinder. Since had been dead for so long, could it have been from a failed AAV?

[@SCVintageAudio2023]

Hi Adam. I'm having issues with my 1987 xjs v12, idle stay always between the 1200 rpm to 1400 rpm and after I drove the car for several minutes warms up then drop to 800/850... that tells me there's something wrong with the AAV of course. but the last week when I fired up the car idle was fine for a min and then was going up and down from 800 to 1500 and dropping to 800 and back to 1500 like a sine wave, up and down up and down... once again! I drove the car for several minutes and idle was back to "normal" 1200 rpm..lol im not sure if this new problem (up and down) with the idle it's related to the AAV... Any ideas ? Thank you in advance. Rodrigo Encina Lethbridge, Alberta CANADA

[@freshbulliesofbellairefres1065]

Adam thank you for your videos. What are the symptoms if the AAV isnt operating correctly?

[@predragbalorda]

Start the car from cold, idle should be around 1000-1200rpm, after about 2-3 minutes you should notice it starts dropping slowly, eventually after 5-6-7 minutes it should drop down to 700rpm or whatever it's set to using the bolt on the aav.

[@zurdoremi]

does he restore the AAV for the 6 cylinder 4.2 ?

[@jaesteban44]

Thank you so much for your videos! You have helped me tremendously with my 1985 XJ-S. One question: will this help the car starting when hot? Mine starts fine when cold and idles real low from the start. If I turn it off and let it sit for 30 minutes and try to start it again, I has trouble keeping idle, it tries to stall until I help it accelerating for a little while. Could this be causing this?? Thank you so much!!

[@LivingWithAClassic]

I'm very glad you like them! Yes it sounds like it could be an AAV issue. If it is stuck the idle would be too low all the time and especially when just started.

[@kyonglee90]

hi, how can i fix small part?..and where is buy the that`parts?

[@CauliflowerMcPugg]

Either you laugh at danger or your wife was out? Sneaking a saucepan into your workshop is dangerous enough but then testing the part the kichen is really spitting in the eye of danger. Well done Lol.

[@LivingWithAClassic]

Haha thank you! Have to be sneaky sometimes

[@Alex-ty5df]

i there, I really enjoy watching your videos very much. Thank you for making and sharing them! I wondered if you had done any videos about the cruise control system, how it works, and how it can be repaired? I am having issues with it and don’t understand its mechanics. Lastly, have you done a video on the auxiliary fan and the relay? The issue that I am having is that sometimes it does not switch off even if the car has been switched off for hours. Now the auxiliary fan is always on when the engine is on and always goes off when I switch off the engine, no matter what the engine temperature is. That is not good either, as I live in the south of Spain and am concerned that if the engine is not cooled down after it is switched off, it may get damaged. I would love to know what the default setting is. Any thoughts you can share with us would be most appreciated. Thank you. Alex

[@helmetdrone]

Adam.....can you give a link to the thermometer plss 👏👏

[@francescopetruzzelli2061]

ciao, devo chiederti una cosa, sul mio xjs v12 1990. dopo il riscaldamento inizio la marcia e si aumenta il minimo, se spengo il motore e' giusto il minimo, se riparto aumenta nuovamente il minimo, cosa posso testare? grazie. Francesco.

[@EinMannUnternehmen]

Great Video! Do i have to drain the coolant system first? Or does it not leak out if i remove the AAV?

[@LivingWithAClassic]

Only a very small amount comes out

[@EinMannUnternehmen]

@@LivingWithAClassic thank you, then i will include it in my winter check up

[@genemccormick3935]

Your right about those two screws really in there. My AAV is original 1987. I did the test several times and it only closed half way. I noticed it has a spring in there. Should replace it with a working used one or get a new one, I don't think your rebuild man works on later models or does he. A brand new one is $205 US. A working used one (after it is tested ) is $75. I am grateful for your video to inform us on idle problems. My V12 idles fine when cold and drives fine but not when warmed up, even pings, not driveable. So step one is fix or replace the unit. I noticed the hose from AAV going to air cleaner has a small factory made open hole. Not sure what thats for? Have a good holiday and New Year.Gene in Canada

[@LivingWithAClassic]

I'm not sure about the factory hole in the hose. What year is the car? He does rebuild them for all the years. He makes new parts and adapts them for the different parts. Hope that you have a good New Year also!

[@jongodsell88]

Gene, the "hole" that you are referring to is for connecting the pipe or tube coming from the top of the distributer cap and acts as a breather pipe for the distributer, without this you are risking a explosion in the distributor. The pipe was originally connect to the larger pipe via a plastic/nylon connector, these though go brittle with age and heat and break. However, when mine disintegrated last year, I used a short length of brass tube about 1/4" in diameter, available at your local model shop and some vacuum hose of a suitable size an length. To fit the brass tube into the larger pipe will, I'm afraid entail at lot of fiddling about. I did mine with the inlet manifold already removed but, in you case I expect, it will entail removing the air cleaner and removing the larger pipe from the AAV. Ensure that it a tight fit in the tube, use a smear of "Vaseline" or washing up liquid to help it into the hole if needs be.

[@genemccormick7567]

@@jongodsell88 Thanks Jon for info my XJ12 is a 1987. I see the hose going under the manifold and hose does not seem loose. I will remove air cleaner and check. I did get a used AAV from local eBayer . A job to install with that rubber elbow..trial n error...hours later success. Jag starts perfectly, perfect cold idle and warm idle too. Now the cat goes like a leaper. Oh the AAV cost me $75 and did kitchen water test like Adam said. Boy we are lucky to have his videos.

[@jongodsell88]

@@genemccormick7567 In my ’88 convertible, there is a short rubber extension in the pipe that has been vulcanised in position, almost in line with the distributor, and it is from here were the vac line (I suppose you could call it) runs from the top of the distributor cap. The tube should not, of course, be loose and should be secured to the AAV by a Jubilee clip. To removed mine, I took the easy option and just cut it off! As the was a new one in the water hose replacement pack. A deal of persuasion was required with a broad bladed screw driver and petroleum jelly, was required to make every thing return to their rightful place; the secret I think is to keep everything slack until the AAV is in securely position and then tighten the Jubilee clips.

[@genemccormick7567]

@@jongodsell88 Jon I did trace that hose from distributor cap and it goes right into air cleaner alloy base. Since I replaced the AAV and elbow rubber the V12 idles perfectly and same when warmed up. On drives perfectly and does not miss a beat. When I removed the AC and non used bellows unit I found two spark plug wires sparking. Replaced them. This was done before I had AAV problems. Thanks to Adams youtube video on the AAV it showed me what had to be done. Adams fuel injector replacement video makes me to inspect the rubber hose on each injector a regular thing. Rockauto have rebuilt injectors for Jaguars by Reman with hose and 'o' ring for $36.78 Canadian or $25.00 US. Of course you would need 12. That injector kit Adam used is very reasonable price wide but' a lot of work.. We see a lot of new vehicle on fires on TV thinking its all that plastic under hood. Well all of todays cars.SUV's and trucks are fuel injected. Too bad they didn't make a V12 with carbs like my 1976 XJ6 I would feel a lot safer. Rule of thumb open your garage doors and after starting V12 get it outside just in case. Thank Jon for your assistance. Gene

[@stigmoltu-jacobsen]

Hi Adam, I’m having a small problem with the idle rpm on my 1981 XJ12H.E (European/UK version). Until recently the idle, cold or warm, had no issues, the car has always run beautifully, ie cold start 1200 rpm, warmed up 750 rpm. Now cold starts 1500 rpm, warmed up 1100 rpm. The car still starts and runs fine, no noises or any other issues. Your video on the AAV is interesting and it may be a problem with mine, which was replaced with a new one from David Manners UK 16 years ago. However, can you think of any other reasons why I have the idle issue? I’ve checked the throttle pedestal, linkages, wiring and gas pedal, all of which seem to work properly. Would greatly appreciate some additional advice. Thank you very much!😉

[@LivingWithAClassic]

Maybe you have a vacuum leak somewhere? I'd start to check that before messing with the AAV again

[@motorcyclementor1785]

Mine was revving high too ( almost 2000 rpm ) and so I removed the intake hose from AAV to manifold and stuck a cork in the manifold. Not an elegant solution but a good temporary measure. It's starts easily and idles perfectly. Just give it a whiff of throttle when you crank it.

[@anthonydavis7704]

I have a 93 Juguar XJ6 4.0 is not getting to the coil

[@trentondycus5383]

R u talking about the idle air control valve

[@LivingWithAClassic]

Yes, called the AAV on the V12

[@ashleyweston5420]

Completely unrelated to the AAV. Remove both sides front exhaust boxes ( think you guys call them mufflers) and replace them with fabricated straight pipes. It's an easy home made modification and your car will sound great while only being a little noisier. If you don't like it it's easy to put them back.

[@darrenrees3816]

I’ve had no luck trying to get hold of Jonas. I’ve tried a couple of times by email and on Facebook. Has anybody else been successful?

[@LivingWithAClassic]

I will message him now and see what happens. I’ll update you