I've been running 89 octane for a year or so, because I was getting some pinging on acceleration. It ping mostly went away on 89, but it bugged me so recently in new knock sensor. Ping was basicly gone. I just cleaned the throttle body, replaced the distributor cap and rotor, fixed the intank fuel pump, and replaced the timing belt. My gas milage went from 18 mpg to 23 (or 24) mpg. So I decided that it was running so much better that I'd try some 87 octane gas. Well the ping is back on acceleration (don't know about sustained highway yet because the muffler went bad and it was too loud.).

What must I do to get rid of this irritation? (other than running the more expensive gas.) Any suggestions are welcome.

Mark,

Here's an easy one for you.

Check your air box thermostat on a warm day.

If it's working, it should be closed on the pipe coming from the exhaust manifold.

If in doubt, just block the tin pipe with something, then make sure only cold air is being let in.

It happened to me that only hot air was being let into the engine, and I was getting pinging on hard acceleration. After blocking the heated air pipe with tin foil, my pinging is completely gone on 89 octane.

Also, I think as long as you are not getting pinging then use the cheapest clean gas available (coming from a gas station that is busy).

Cheers,

Hello,

Forget about messing with the timing to get rid of it. If that was a solution then Volvo would have designed the B230F to have timing set that way and use cheap ass gas. Note in the owner's manual (if you have one) that the recommended fuel is an AKI (anti-knock index) eqiuvalent of 89. For those of us in North America, that translates into a RON (research octane number) of 91. Hence premium fuel is required for your 240 to not ping, go through plugs prematurely, gum up your catalytic converter and of course pass your next emissions test.

Here's my two cents. Or three. There are 3 life bloods to your engine. Oil, coolant and gas. Go cheap on any (or combination thereof) and you risk unpredictable issues with your brick. Out of all three I would consider fuel to be the most valuable of the bunch. Premium will give better mileage, so the difference in cost will be partly offset. Plus most gas stations typically give you more "bonus bucks" or "points" or whatever purchase incentive for using their premium fuel. The rest you will save in longer lasting basic tune-up items.

Happy Bricking!!!

Richard

87 245 DL 355,000 km
82 242 GLT 121,000 km

http://members.cardomain.com/richink

P.S. - Out of the last 4 bricks that I have owned and used premium in, not a single fuel or cold start injector has failed in over 450,000 km of driving - COINCIDENCE???

There are 3 grades of fuel most commonly sold in the USA. Not really sure what premium means nowadays. At the pump they are referred to as AKI 87 89 and 91. AKI is the average of RON and MON (or RON+MON/2) but this irrevelent because the pumps display the AKI rating only. Our Volvos are designed to run on AKI 89, the mid grade. Running on 91 will neither increase power or mileage and is waste of good money. (Oh how we must deal with so many myths.)

If the B230 engines pings on AKI 89 there is a problem to be corrected and is most likely base timing (should be set at 12 degrees BTC) or the knock sensor.
--
David Hunter

Stick with the 89. Your mileage will be better and your engine will stay cleaner. That's the octane Volvo designed your engine to use.

Any suggestions? Do I need a knock sensor?

But shouldn't the engine be happy at this octane even with NO knock sensor?

Thanks for any help you can give.

Doug Harvey

89/92 mix, is not a good idea,when mixin fuels like that, your yealding a lower octane than the cheeper 87 octane.
This happend cause the fuel grades have different detergents and addetivs and when wixed the detergents clash with the octane and over power the octane and lower the octane. PING ON!!
--
Kevin * HONDA spanking,1985 240DL * VOLVO ON!!!!

Retard the ignition timing and pinging will go away. I run the cheepest gas I can find my B230F pings at 14*BTDC at 12*BTDC there is no pinging and loads of power,10*BTDC no power.

Hope this helps.
--
Kevin * HONDA spanking,1985 240DL * VOLVO ON!!!!

I think you basically gotta live with it. I can run anything in my 93 245 when the ambient temperature is low. When summer comes around in Dallas, I have to run 89. Last year I was having pinging even with 93 and replaced the knock sensor like you and improved it greatly. Make sure you torqued it properly. As I remember, it was a pretty low value and required the use of an inch-pound torque wrench.