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Discussion Starter · #1 ·
Hi all just searching for ideas really, I own a DB7 v12 . unfortunately lately when driving the idle rpm increases to between 2000 to 3000 rpm making it a tad difficult to drive, i have also found when left idling in our driveway for a while the rpm will also increase significantly. the only way it will drop in rpm is to turn off the engine and restart . this drops the rpm but not back to the correct rpm.
any advise, ideas appreciated
cheers kevin
 

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That is odd. Wonder what the ECU is seeing that is giving it heartburn? Do you have a scanner handy? Throwing any codes? The basics would be checking the throttle bodies and see if something is loose, sticking, gummed up where the air is coming in through the big hoses on both sides of the front of the engine; or a vacuum leak/broken vacuum hose. I'll look at mine, but I seem to recall throttle position sensors on the outside of each of the throttle bodies, that would probably be a twenty year old electronic part, sitting in a ridiculously hot engine bay if it is still original, plus the bodies can get loose and let unmetered air through.
 

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Discussion Starter · #3 ·
yes it is strange, my scanner has failed so im looking to purchase a new one, all vacuum hoses replace about 12 months ago, i am going to clean the throttle bodies in the near future and see what that does. cheers kevin
 

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Hi Kevinr61:

I had this same problem but it was after I had removed and replaced all the fuel injectors after having them cleaned. As 'ipadctr' recommends I would first look at the throttle cable connections at the throttle body (ball sockets) and also where they connect to the 'throttle tower' as seen on the 2 pages I have attached from the DB7 Workshop Manual. Remove the engine bay panels to reveal these connections. Apply some WD-40 and work your gas pedal to see if this frees up the sticky cables? That did it for me and that problem went away. Perhaps this will do it for you as well. Always start with the simplest and most obvious fix first before tearing things apart that you don't need to.

Good luck,
johnfe
 

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Hello Kevinr61 and devilspns:

After reassembling mine after replacing all 12 spark plugs with the upgraded Iridium plugs, verifying I had the 2 generation coils, sending out all 12 fuel injectors for cleaning plus upgrading with elastomer o-rings, replacing all the necessary gaskets, which I included replacing the cam cover gaskets while I was in there, I unfortunately made the error of applying some moly grease to the throttle cable ball sockets and added a small amount at the throttle tower connections as well. This grease was too thick causing the throttle cable connections to hang where the revs would not go back to their normal range once my foot was off the gas pedal.
But after applying some WD-40 this thinned out the grease enough for the cable connections to work freely. BTW, Kevin61 the vacuum hoses to and aft the PCR valves are notorious for leaking due to the oil build up there causing the rubber to swell and eventually leak. This happened to mine which caused many "CEL" warnings driving me crazy. The PO's service records showed multiple times shops changed out the O2 sensors, never actually fixing the problem. I used 4 jubilee clamps eliminating those leaks and have never had a CEL light go off since.

johnfe
 

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Hi devilspns:

Another area which has the potential to cause 'CEL' light problems are the fuel injectors as the ones on the DB7 have a tendency to stick form time to time which can cause misfires. This is mainly due to the alcohol additive used in the gasoline fuels. Something I heard on the radio recently was; here in California they are going to be increasing the alcohol content from 10% to 15% in an effort to lower the cost of the gasoline and this has the potential to increase problems that alcohol additives cause. I have tried the 'Sta-Bil' fuel stabiliser and wasn't that impressed. However twice now when this issue has come up, this product solved it:


Just note all the 5 star reviews this product has. I guess 5,342 folks can't all be wrong on how well this product works! LOL! I now add this to my fuel everytime I fill up and since doing so have never again had a sticking fuel injector even after not driving the car for over 3 months.

johnfe
 

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Hi devilspns:

Another area which has the potential to cause 'CEL' light problems are the fuel injectors as the ones on the DB7 have a tendency to stick form time to time which can cause misfires. This is mainly due to the alcohol additive used in the gasoline fuels. Something I heard on the radio recently was; here in California they are going to be increasing the alcohol content from 10% to 15% in an effort to lower the cost of the gasoline and this has the potential to increase problems that alcohol additives cause. I have tried the 'Sta-Bil' fuel stabiliser and wasn't that impressed. However twice now when this issue has come up, this product solved it:


Just note all the 5 star reviews this product has. I guess 5,342 folks can't all be wrong on how well this product works! LOL! I now add this to my fuel everytime I fill up and since doing so have never again had a sticking fuel injector even after not driving the car for over 3 months.

johnfe
Hello johnfe,

A very useful treatment by all accounts,but ling in U.K. difficult to get at a fair price.Although treatment
reasonable postage can be as much as £58 on a small bottle ??? This making it a total waste when l can
buy at a similar item for far less.I have however found one,but it is 10013 so not sure as to it being as good !
Can buy a gallon at £40 which makes it worth while if it does same job,works for diesel and petrol,cleaning
top end and injectors,also by the same company.Could you help with this please,many thanks.

Regards

devilspns
 

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Should read "living in U.K. "
Hi devilspns:

Honestly I think the product number difference has to do with the size only. I found this link which shows the gallon size:


And be sure to check out its number of 5 star ratings!! 10,266 folks can't all be wrong! Even more than before!! LOL! Also shows 436 questions answered as well. I have 2 quarts of the stuff sitting in my garage right now which I use in my DB7VV gasoline/petrol everytime I fill up. This was before I knew there was/is a gallon size available. I have no doubt it's the same, just a larger size. Once you start using it in your Aston you'll never stop, trust me it's really that good. After, I had my fuel injectors professionally cleaned I was told to install and use them right away and to avoid letting them sit on the shelf due to a potential for sticking . But circumstances beyond my control prevented this (needed new cam cover gaskets from England) so once they were installed I got a couple of misfires causing a CEL light to come on, which I'm certain were caused by sticking injectors.
I then added the Lucas fuel treatment to my fuel and the problem went away and has never returned since! There are 3 things that are essential to prevent 'CEL' lights from popping up in the DB7: No Vacuum Leaks, No sticking fuel injectors, and a battery that's at 100% of its charge. My DB7 runs beautifully and is such a joy to drive when all 12 cylinders are firing as they should!

Kind regards,

johnfe
 

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Hi devilspns:

Honestly I think the product number difference has to do with the size only. I found this link which shows the gallon size:


And be sure to check out its number of 5 star ratings!! 10,266 folks can't all be wrong! Even more than before!! LOL! Also shows 436 questions answered as well. I have 2 quarts of the stuff sitting in my garage right now which I use in my DB7VV gasoline/petrol everytime I fill up. This was before I knew there was/is a gallon size available. I have no doubt it's the same, just a larger size. Once you start using it in your Aston you'll never stop, trust me it's really that good. After, I had my fuel injectors professionally cleaned I was told to install and use them right away and to avoid letting them sit on the shelf due to a potential for sticking . But circumstances beyond my control prevented this (needed new cam cover gaskets from England) so once they were installed I got a couple of misfires causing a CEL light to come on, which I'm certain were caused by sticking injectors.
I then added the Lucas fuel treatment to my fuel and the problem went away and has never returned since! There are 3 things that are essential to prevent 'CEL' lights from popping up in the DB7: No Vacuum Leaks, No sticking fuel injectors, and a battery that's at 100% of its charge. My DB7 runs beautifully and is such a joy to drive when all 12 cylinders are firing as they should!

Kind regards,

johnfe
That is indeed good news,also the fact that the 10013 is more or less
the same as the 10020.Was thinking there might be a problem there,but
it seems not.Have ordered 2 ltrs for now but a gallon next time.Thank you
for your assistance greatly appreciated.

devilspns
 

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That is indeed good news,also the fact that the 10013 is more or less
the same as the 10020.Was thinking there might be a problem there,but
it seems not.Have ordered 2 ltrs for now but a gallon next time.Thank you
for your assistance greatly appreciated.

devilspns
You're most welcome devilspns, I'm only too happy to help.

johnfe
 

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Hi Kevinr61:

I had this same problem but it was after I had removed and replaced all the fuel injectors after having them cleaned. As 'ipadctr' recommends I would first look at the throttle cable connections at the throttle body (ball sockets) and also where they connect to the 'throttle tower' as seen on the 2 pages I have attached from the DB7 Workshop Manual. Remove the engine bay panels to reveal these connections. Apply some WD-40 and work your gas pedal to see if this frees up the sticky cables? That did it for me and that problem went away. Perhaps this will do it for you as well. Always start with the simplest and most obvious fix first before tearing things apart that you don't need to.

Good luck,
johnfe
To be frank with you John,l have spent most of my life fixing and repairing my and other peoples cars.Now in my 74th year with C.O.P.D.,Asthma,Diabetes 2,Osteoporosis,and Cancer l find it difficult to find someone to help me.
This l find is life now,and if it where not for an ex BMW mechanic (now on Audi) and the odd bit of assistance from an ex-Aston mechanic l would be lost for the physical side of things.l obviously do the service side of things,oil changing now so easy being able to pump out old from top of engine.Which also does not disturb the sump bolt so no leak there.Polishing much easier after putting on nano coating,that and Rain-X on glass makes it a lot easier.Also carry a garage type jack when traveling distance as have spare wheel.

Regards

devilspns
 

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Hi devilspns:
First off I'm sorry to hear about your health which I'm sure you know at your age is number one! So please do all you can do on that front to never give up and never surrender as Winston Churchill once said during WWII. I'm a young one at 72 and quite fortunate as far as my health goes and I'm recently only fighting the battle of the bulge with my waist line as I recently quit smoking 8 months ago and I'm quite lucky that I have no C.O.P.D. after smoking for some 42 years. I only started in my thirties and didn't start when I was young. As far as automobiles go I started working on cars when I was fifteen. Since I'm an 'Army Brat' lol; my Father had bought a 3.4 liter Jaguar Sedan while we lived in Yokohama Japan. And during a tour of duty in Alaska his Jaguar would no longer charge the battery. He told me if I could fix it, he would give the car to me to drive to High School in it. Since we lived on Fort Richardson next to Elmendorf Air Force base I took his car to a bay where I could check out some tools and found the generator had thrown some solder where a wire had come loose from the commutator. Once soldered back the generator started to function again. I got lucky and due to that luck liked working on cars. I later at seventeen worked at a place called Gupton's Sinclair (a gas station) where I rebuilt motors and learned a lot about repairing cars. Due to that Jaguar I started my passion for English cars.
I have owned a 1967 Triumph GT6, a 1971 Jaguar XKE Roadster, and now my 2003 Aston Martin DB7 Vantage Volante manual stick shift. After buying the DB7VV it had the nasty habit of throwing up 'CEL' lights, where I did everything I could to resolve that issue. During the first several years of ownership all I ever did was 'Drive Cycles' only to have another 'CEL' light come back on, it was maddening! As luck would have it I repaired just about everything such as installing new Air Filters, cleaning the MAF sensors, replacing the the fuel filters, and fuel pumps and removed the intake manifolds to make sure I had the second generation coils, upgraded the spark plugs to the Iridium plugs, and sent the fuel injectors out for a professional cleaning. I tested the fuel rails to make sure they had the right amount of fuel pressure as well. I also replaced all the O2 Lambda sensors as well, and after all that I still had the 'CEL' light issue. That's when I finally did a in line Vacuum test I found the vacuum leaks at the PCV valves, and that finally resolved the issue, but only after checking the CPU's as well! What was happening is due to the additional oxygen entering the system thru the leaks the car's CPU's would try to compensate by richening the fuel mixture where it was never able overcome the lean mixture caused by the vacuum systems leaks.
Since I live in SoCal in order to pass the SMOG tests all the vehicle's computers had to show an OK with an OBDII scanner. Without that I could not get the car registered to get a sticker for my license plate to drive the vehicle. I did the 'Drive Cycle' as outlined in the OBDII manual so many times I became a professional at doing it where I can now do a 'Drive Cycle' on a single run and get all the computers to show OK on a single run!
I'm also a member of the AMOC Forum where I got a lot of help and advice to fix all the issues I've outlined above. In particular on that forum there's a guy named William Temple who is a walking encyclopedia when it comes to the DB7. I also joined the Aston Martin Technical website for a period of 24 hours where I was able to download all the technical documents about my vehicle.
Car Wheel Vehicle Tire Plant

Here's a picture of my DB7 above. If I can be of any technical assistance please just ask.

Best Regards,

John F Edwards aka johnfe
 

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I did not start until l was 17 and it was small servicing work.If fit enough l could now
strip the engine on a MK1 Ford Cortina a Triumph Spitfire,MGB, Triumph Stag and most
V8's.As well as BMW M3 and Aston Martin DB7 straight 6. Amazing what you can learn over time.
Now down to mending phones,watches and computers,all nice light weight jobs in the warm !!
Was a member of AMOC left before it changed,but managed to get all tech data first.

Nice clean looking car you have,and as you can see l have the Coupe in Sutherland Red.
Speak again.

Regards

Syd A.R.Bell.
 
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