Throttle butterfly

Post by **fume** » 18 Jan 2007 09:33 am

Does anybody know what the throttle butterfly to choke flap clearance should be? on my car the end of the screw is touching the choke flap, haynes shows you how to adjust it but not what the gap should be! but i take it there should be a gap rather than it touching like on my car.

Also has anyone found any benefit from using shell v-power petrol, is it worth the extra money?

Post by **Chris_C** » 18 Jan 2007 12:15 pm

You sure it's not in Haynes? Thought I found it there, must be dreaming things again!!! I have a big book of carbs here I need to give back to a mate I'll have a check for you!!

Post by **fume** » 18 Jan 2007 01:36 pm

I have hunted through haynes unless i am being daft but i can't find it, but sometimes there not the easiest things to use

Post by **pettaw** » 18 Jan 2007 06:48 pm

Hmm odd that it would be touching. What's the reason for checking it? Is the engine massively over-revving on choke? These 1.7s seem to have a lot of throttle stop anyway, so idling between 1700 and 2000 on choke is fairly normal.

The setting is 2.0mm according to the books, IIRC, but in practice the factories set them up considerably lower than that to open the throttle more. I would suggest about 1.3-1.5mm.

Stupid question, but just make sure the choke is 100% off completely when you take the measurement. The cables on these have a nasty habit of changing shape and pulling the choke on when the underbonnet temperatures rise.

Post by **fume** » 18 Jan 2007 09:34 pm

Thats a great help thank you. If you start the car in the morning after a mildish night on full choke it will rev anything upto 2500 rpm. Maybe i am wrong using full choke but i was told by an ex volvo service bloke that you should always use full choke to start a 1.7 if it has stood for a while. On my last 1.7 this worked well but this one hardly needs any choke compared to my last one.

Post by **pettaw** » 19 Jan 2007 01:10 am

Sounds fine to me mate, and yeah you should always use full choke to start the car up if its been standing overnight. As soon as it fires I would slowly push it in until the revs rise and settle at about 2000.

Post by **fume** » 30 Jan 2007 09:39 am

Have now adjusted throttle butterfly to 1.5 mm its now difficult to start in the mornings and runs awful until you can push the choke in. When its warm it idles ok and on drive home from work last night ran really well, it even felt quite quick!.

Post by **foggyjames** » 31 Jan 2007 08:23 pm

I'm having the same fun with my 240 at the moment. I say sod the manual and adjust it until it's happy.

Regarding V-Power...it only gives a 'power increase' if you have 'responsive' mapped ignition with knock sensor, which advances the timing until it detects knock, then backs it off a few degrees. 300s don't have this, so they don't benefit. It's a relatively 'modern car' thing.

The only time you need to run higher octane fuel is if you have an older 300 which was designed to run on higher octane (i.e. leaded) fuel than 95 octane unleaded, else the car will pink slightly under load.

In other words, in non-300 specific terms, if your car dates from the pre-unleaded era (for Volvos, generally 1986), you probably should run 'super unleaded' - whichever brand...and if you have a car from the mid 90s onwards (in some cases earlier), you'll see a mild boost in performance on the happy juice. For late-model 300s, there's little point in running anything other than standard 95 octane.

cheers

James

Post by **pettaw** » 31 Jan 2007 09:30 pm

James is right, but do make sure its got a high detergent content. I like to run V-power in my red GLT occasionally which is setup for 95 unleaded, because of the higher detergent content. It may be me falling for the hype but I do believe that after a tankful and a good hard run, it does run better.

Post by **foggyjames** » 31 Jan 2007 10:45 pm

Are all fuels made equal? Perhaps not. Latterly (with the old CISAC carb), I think my 360 had a slight air leak...and I swear it ran better on Shell's 95 octane than anyone else's.

cheers

James

Post by MJ » 31 Jan 2007 10:51 pm

I'm with Andy, we like to use V-power, but I've never done any kind of comparison.

I'd never trust supermarket fuel as they seem to interested in cheap prices rather than quality, and your car is what it drinks

Post by **SteveP** » 31 Jan 2007 11:00 pm

MJ wrote:I'm with Andy, we like to use V-power, but I've never done any kind of comparison.

Well maybe on a car that doesn't get driven very far the added expense isn't too bad

Post by **foggyjames** » 31 Jan 2007 11:02 pm

BTW....I don't use Shell fuel now...I'd have to drive miles to get it

cheers

James

Post by **Ronnie** » 01 Feb 2007 12:13 am

MJ wrote: I'd never trust supermarket fuel as they seem to interested in cheap prices rather than quality, and your car is what it drinks

Tesco sell 99 RON petrol, and it's cheap - I don't use anything else

Post by **germ** » 01 Feb 2007 12:21 am

i dont know why you worry so much about the petrol you use its all made to a set standard v-power fuel is a gimick to make you buy it

set standard but octane is differnt if v-power is 98 and the supermarket stuff is 98 then its the same!

in france it says 88 and 85 octane why is this it also says: if your car uses 95 use 85 and if your car uses 98 use 88

Why is this?

Cheers
will