

| Subject: | Re: Ping/Knock/Detonation |
| From: | John Rodgers |
| Date: | Sat, 20 Jan 2007 20:39:17 -0600 |
Jake, that method sounds interesting. Would you please expand on it a bit. I have a small ping in a certain range under load as in climbing a big hill. Have nto been able to get rid of it. This might do it. Thanks, John Rodgers 88 GL Driver Jake de Villiers wrote: > You might try the total timing method Michael. > > Set the timing with an advance timing light to the total required > advance at > 2500-3000 RPM and treat the resultant advance at idle as an artifact. > > I've used this method on many modified engines over the years to good > effect. > > Jake > > On 1/20/07, Michael Diehr <md03@xochi.com> wrote: >> >> The rebuild & install was done by a shop (who I won't name but I hear >> is of extremely dubious reputation I'm told -- I was aware of that >> going in but a move forced my hand) and I have no idea what they did >> or did not do when installing the 2.1 into my 85. I believe that >> when I got the rebuild home, I measured the timing at idle as per >> bently (DIS disconnected etc.) and it was spot on. However, that >> was 4000 miles ago. >> >> Anyone on the list have an opinion as to how much total time pinging >> it would take to fry my engine? 1 second? 10 seconds? 10 >> minutes? Should I just assume the engine is toast, find a new >> mechanic, drop the van off, and fly home? :-) Anyone know when the >> Zetec conversion will be CARB approved? >> >> On Jan 20, 2007, at 11:10 AM, Dennis Haynes wrote: >> >> > Did you convert to the cooling system with the oil cooler to also >> > cool the >> > pistons? Detonation is extremely speed and load over time >> > sensitive. The 1.9 >> > FI system should not be a problem, both use the same injectors. Is the >> > timing set to spec or slightly advanced? Get it set back down. Make >> > sure the >> > vacuum retard on the distributor is working to reduce the timing >> > during part >> > load to reduce the peak flame temperatures. Pinging actually occurs >> > long >> > before you hear it. While pinging, you working at busting rings, >> > melting >> > pistons, and burning valves or even cracking heads. This is where >> > EGR could >> > be helpful but the Vanagon does not have it. >> > >> > Dennis >> > >> > >> > -----Original Message----- >> > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On >> > Behalf Of >> > Michael Diehr >> > Sent: Saturday, January 20, 2007 1:02 PM >> > To: vanagon@GERRY.VANAGON.COM >> > Subject: Ping/Knock/Detonation >> > >> > I'm finishing up a long (3K miles) road trip and the van has been >> > running like a champ (for the first time ever, wahoo!). However, >> > I've noticed a problem with pinging (aka knock aka detonation). >> > It's very particular -- it only happens at 1/2 throttle or higher at >> > 3200 thru 3500 rpm, even on 91 or 92 octane gas. Happens most of >> > the time -- only exception seems to be at temperatures of 30F and >> > lower at 3000F altitude or higher, which seems very consistent with >> > it being ping (heat & pressure related). >> > >> > As far as I know, the timing of the engine is good at idle, but I >> > doubt that the advance has ever been tested. >> > >> > This is a 85 westy automatic with a newly rebuilt 2.1L block >> > installed (about 5k miles post rebuild). It has the stock 1.9FI >> > system, including a rebuilt computer & distributor & afm. >> > >> > It seems weird to me that the RPM range is so specific -- it really >> > only does it at that particular RPM range. Any ideas? Bad >> > distributor advance? Flat spot in the AFM? 1.9L FI system not >> > well matched to a 2.1L block? >> > > > > -- > Jake > 1984 Vanagon GL > 1986 Westy Weekender "Dixie" > www.crescentbeachguitar.com > >
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