3.2 Pinging!

bklyn · 12-24-2008, 06:52 AM

Gents, I have a 1987 3.2 with cat bypass, Bursch muffler, SW chip and KN drop in filter. I just developed a slight pinging under load. I always use 93 Octane and recently ran some Sea Foam through. Any Ideas?

88911coupe · 12-24-2008, 06:57 AM

Just a guess, but my '88 was burning a lot of oil due to worn valve guides when I tore it down for the rebuild I found it had substantial carbon build up on the pistons which (I think) caused my car to ping under load on occasion. Not sure if this applies to your situation or not though...

bklyn · 12-24-2008, 07:11 AM

Could be but engine was completely rebuilt, upper and lower three years ago.

db_cooper · db_cooper's Garage

The fuel we are getting now is just awful, even when labeled 93 octane. My own experience with a Laverda 1000, which I've had for over thirty years, confirms this.

After running fine for years I developed a slight ping at 3800 rpm, under load this summer.

I had to "re tune" the engine with a flatter advance curve and backing up the timing 3 degrees total advance to cure it. Jetting also went slightly leaner too.

You may want to revisit the chip you installed, or, play with the DME fuel/timing adjuster and retard the timing.

Good news is you can hear the pinging and can address it. Be careful as you can still have too much advance and not hear the pinging. Watch your plugs!

bklyn · 12-24-2008, 07:50 AM

Thanks, same thought about the fuel, I plan on contacting SW after the Holidays.

JeremyD · JeremyD's Garage

Where did you buy your last load of fuel? I am very particular about where I buy gas - Florida has lots of independent distributors - you never know what you get. I'd find some race gas and put 5 gallons in there just to be safe.

cgarr · cgarr's Garage

You could retard your timing or rich up the mixture with the selector switch on the DME and see if it helps.

bklyn · 12-24-2008, 09:42 AM

I hate to admit but I go to Sunoco, it has 93 octane. My other choice is Racetrac (not good) also I have my DME all the way up as per SW. No good?

Steve W · Steve W's Garage

Lenny just emailed me about the problem, and going through the past service records, just found out that the PO installed higher compression Euro pistons and cylinders, which are about a full point higher in compression. So the standard U.S. chip program won't work properly for pump gas, and he's going to have his chip customized with different ignition curves to address this.

JeremyD · JeremyD's Garage

Well that will do it!

Roc Doc · 12-24-2008, 07:29 PM

Quote:

Originally Posted by Steve W

Lenny just emailed me about the problem, and going through the past service records, just found out that the PO installed higher compression Euro pistons and cylinders, which are about a full point higher in compression. So the standard U.S. chip program won't work properly for pump gas, and he's going to have his chip customized with different ignition curves to address this.

Thanks for clearing that up.

I can get 100 octane fuel here pretty easy, but I usually just run 91 or in the winter 89, and I have no pinging problems. This with a stock 3.2, and at 2300 ft of altitude.

bklyn · 12-25-2008, 03:14 PM

Yes gents, going through the Po invoices I learned that approx. three years ago the engine was rebuilt, upper and lower. (great) But what I did not know at the time I purchased my SW chip was th orig. owner had installed 3.2 Euro spec Mahile pistons and cylinders. DAAAA. Its good news for me. I already packed up my SW chip and its on its way to be re-programmed. SW got back to me in a matter of only moments after I told him about the Euro spec's. Good people!! For-sure