For those of you who were there and especially those who were not I must tell you all the story of what started as a simple linkage adjustment.
We (My Wife and I) drove our 69 280SL to Columbus from Rochester NY to attend the PUB at Joe Alexanders. Knowing full well that my car was in desperate need to some good advise that I could not find here in my home town.
My car has been running poorly ever since it first became mine bask in November 2008. I have struggled along trying to get it running consistantly to no avail. I have adjusted and re-adjusted the linkage, the injection pump, the idle air screw, the timing, the plugs but could never get a real handle on it. It ran rich, in ran lean, it had a bad case of hesitation and a pretty good back-fire condition.
On Saturday of the PUB Joe produced the infamous 10mm stud to start me off on the correct linkage adjustment as the only way I could get m y car to run was to have the IP down rod 250 mm long. Of course I knew that once this was complete the car wouldn't run. I was also convinced that the IP adjustment screw was either frozen or broken as it did not turn.
Joe reached down for the adjustment screw and immediately determined that it was backed out all the way (LEAN) and the internal screw was stuck up against the external screw. He not only found the cog to begin adjusting it again back toward rich. Of course now the car idled again, much better that before. Upon a test drive however there was still something wrong, as strong back fire between 1st and 2nd gear and the hesitation problem was a prevalent as ever. Joe suggested I come back on Monday morning for a bit more detailed look at what might be going on.
Monday's drive to Joe's from the hotel was a challenge as the car was not happy with the adjustment.
Once at Joe's we removed the valve cover and check them Cam and Crank Shaft timing. With the Crank shaft at 0 degrees on the balancer the notch on the cam should have been in line with the casting mark on the Cam tower. No way, not even close. Did the Chain jump a link or two, was it installed that way, why would the valves be so retarded from the crank shaft.
Well in all actuality they were not as far off as we had first determined. Yes there are (2) sets of timing marks on my Harmonic Balancer. An outer ring set of marks for Early Cars and an Inner Set for Late Cars. Mine is a Late Car and each set of timing marks has a distinctly different Pointer attached to the front of the block. We of course in our haste, lack of sleep and lack of time were in fact reading the wrong scale. Not that that lead us to far from our intended goal or off in some wrong direction but our best efforts in slipping the cam gear off the cam, advancing it, re-installing gave us better results but still was not running as it should.
I left Columbus for the 7 hour ride home with a car that ran only slightly better that when I arrived but I had gain some invaluable experience not only from Joe Alexander but from many in attendance who had offered advise as well as hands on help. We did get home OK, but along the way the car started to skip or misfire almost like the ignition was turning off for a split second.
Upon arrival at home I started again where we had left off in Columbus, I removed the linkage, valve cover and spark plugs, hooked up a remote starter and spun the motor over several time to get the balancer at 0, making sure the piston was at the top through the spark plug hole. The Cam was Retarded. I turn the motor over by hand until the notch on the cam was in line with the casting mark and read the balance scale to determine exactly how off it was, 10 Degrees Retarded. From what I learned at the PUB, each link in the timing chain is equal to 18 degrees of rotation so I slipped the chain off the cam, and advance it one tooth, but now it was going to be 8 degrees advanced. I purchased an OFF-SET KEY for the camshaft and installed it make up the difference. Once all assembled again, I turned the motor over several time to ensure that all of the marks lined up and they most definitely did.
Additionally when ordering the cam keys I ordered a new electronic ignition system. I had previously replaced the points with a Crane FIRE-BALL ignition system right after I received the car but have heard several stories of them failing by some other participants and having noticed the skip in firing on the way home, I decided it could not hurt and would be one less thing to have to eliminate.
This Sunday I finished putting everything back together. As I was removing the old coil, I happened to turn it upside down and fluid was dripping from it. It definitely had some issues. I have not yet measured the resistance of it but once the new ignition was installed and the timing was set to 30 Degrees advance at 3000RPM my car runs better that it ever has I am sure in quite some time, ever long before I owned it.
The hesitation issue is gone, it excellerates smoothly through the gears, there is no longer a skip of fault at high rpm's. there is still a slight hint of a back fire upon deceleration which I am sure a little more tuning will eliminate but OMG what a difference.
I really loved this car from the first time I laid eyes on it but have been pretty disappointed in its performance or lack there of and my inability to get to the bottom of it. If you have a good honest mechanic in your area, make a point to pay him a compliment, if you don't don't be afraid to ask anyone who is member of this group for help. Everyone has something to contribute and some really do know just about Everything there is know about these cars, or certainly know where to look.
Thank you especially to Joe Alexander for his help and guidance and to everyone who helped even in the smallest way.
Today it is sunny and 80 degrees here in western New York, the car is outside my office window, the top is down and I can't wait to get the H&$LL out here and take her for a ride.
Tony
