Remco is right, if you have a lean-out situation due to a dirty carb, bad accelerator pump, floats set too low etc, you can get engine knock, and carbon buildup can also be a culprit. You can make a quick check of your distributor with a timing light. If you get erratic movements of the harmonic balancer's timing mark, you could have a bad distributor. If the mark moves smoothly between idle, higher RPMs, and back again, your distributor is probably alright. Watch your dwell angle too, it should remain pretty constant throughout RPM changes. Remember, dwell affects timing, but timing does not affect dwell. Bill & Tami Roddick 1964 Imperial Crown 4 DR HT 1972 'Cuda 340 (Tami's Toy) 1988 Cherokee Laredo 1995 Concorde ----- Original Message ----- From: "r.van.Lent" <remco.nancy@xxxxxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Sunday, March 07, 2004 2:34 PM Subject: Re: IML: Spark Knock in my '59 > is the carb clean and is the accelerator pump working > if carb is not clean mixture can get to lean and give engine knock > 75000 miles can be enough to have a lot of carbon build up in the cill heads > becouse this knock can happen > Remco > The netherlands > ----- Original Message ----- > From: "Rex Crews" <rexcrews@xxxxxxxxxxxxx> > To: <mailing-list@xxxxxxxxxxxxxxxx> > Sent: Sunday, March 07, 2004 11:20 PM > Subject: IML: Spark Knock in my '59 > > > > Hi, Guys and Gals, > > > > I would like some feedback on spark knocking or pinging on my '59. I have > > changed the points, checked, set and re-set the timing, and bought > different > > gasolines. Still, I have a weird problem with spark knock on acceleration > > and can even hear it at high speeds. The odd symptom is, though, that the > > problem is not consistent. One day it doesn't ping at all, and the next > day > > it is terrible. My mechanic thinks the distributor shaft is worn and is > > shifting the timing, but the car has only 75,000 original miles. Any > > suggestions about the cause? BTW, my 60 and 61 Imperials have zero spark > > knock.... Thanks in advance. > > > > Rex Crews '59 and '60 Crowns, '61 Custom > > > > > >