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| Joined: | 09-17-2007 |
| Location: | San Francisco, California USA |
| Posts: | 221 |
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Got her all together and degree'd the cam to a very fine resolution. Starts with ease now without any choke and hardly any priming or throttle. Had her out the last few weekends doing some tuning with the new wideband setup.
Was starting to do some 4500-redline pulls to judge the top end throttle response and just as I was coming home of the freeway she stuttered and make some pops and then went to really low power, then shut off. Barely got onto the shoulder as I went for the nearest exit.
In the last 20 years I have forgotten my cell phone at home maybe two or three times. Here was the forth. I found myself desperately trying to get her started with no luck. Plenty of gas, the entire ignition system brand new, and everything basically together and tight. No puddles of fluid under the car. No loud noises or horrible sounds- the starter just spun her around and around.
I had a nervous breakdown in sitting on the side of the road, with the cars wizzing by at 90 mph. This is on 280 north right at the border leading into SF, a 6 lane freeway. I thought the worst- I broke a valve, something had slipped on the cam pulleys, a rod was loose- every nightmare flashed before my eyes.
I took time to compose myself and realized I was only about a 1/2 mile from home. I put on the emergency lights and ran back home, phoned AAA, and got a tow. Took my other car and pulled up behind her.
No cops, no nothing, as if no one noticed. She had been sitting there for at least an hour and a half. Tow guy was nice and we towed it back to my driveway. It was getting late so I let her sit, but broke down at around midnight and couldn't sleep thinking about what the hell was going on. I ran out in the night and did a compression test- 150 psi all the way around! So no major problems, I was so relieved.
Today I tested spark- nothing. Cylinder #2 had a little, but the others nothing. I thought about my "custom" Lucas 43D I had ordered from the UK and then machined an oil seal recess for. So far it hadn't given me any trouble at all. I suspected the advance curve to be not great or well matched to a Lotus 907, but nothing major. I took the distributor out and set up a bench test with a 12v battery. I must have been a little tired because somehow I think I crossed a wire using some alligator clips, and as I turned to dizzy to see if the switch was still good I saw a puff of black smoke. YIKES. Now I couldn't figure out if the switch was bad before I had smoked it, but it did fire off fine for a few seconds.
I felt like jumping out the window for a few minutes, then I again gathered myself and dusted off the old original distributor. I had rebuilt it before I got the new 43D, replacing the oil seal because it was leaking badly. I had stripped out my old Petronix Ignitor I years ago, and still had it in a box. I thought I had toasted the Petronix, but something told me to give it another shot. But it all back together and returned to the car to install. Things started to get super weird. I could not, for the life of me, get the distributor to snap into the socket and get the dizzy wheel to spin the rotor! It was as if something was not meshing in there, the dizzy pulley spun around and around and the rotor didn't even twitch. I always had problems with this in the past but it always eventually popped back into place.
Getting frustrated, I pulled everything out and got the 43D back in there, and viola- it too DID NOT MESH! What was happening here? I felt completely lost. Then I had an epiphany. I had noticed that the dizzy pulley, before all this, was having some problems centering the cam belt. The cam belt seemed to be drifting towards the engine, and was off the pulley by 1mm or so. Since I had replaced the tensioner with a setup from Gary Kemp, I had always chalked this up to being a tel tracking issue with the newer style single piece tensioner wheel with the integral Flennor bearing.
But wait a second- was the pulley wheel drifting outwards, away from the engine? When I removed the dizzy pulley months ago, I remember tapping on it with a hammer. So I got a rubber mallet, and gently tapped it back in towards the engine. It floated a few mm's and suddenly all problems were solved- the distributor now could mesh up with the drive cog, the belt was back to tracking dead center, and life made sense again.
So I smoked my new 43D's switch, and now am running the old converted 25D with a new oil seal and my old Petronix I thought was dead. LOL. Funny times, but I will take. It caused me to realize this fact: the original advance curve and centrifugal weights is far superior to the "mix and match" mystery setup on the new distributors that these companies claim works with the 907. She is running a lot smoother and the ignition advance, even though it seemed to read the right degrees statically at the right rpms (around 5-7 degrees at idle, up to about 25 degrees at 2700 rpm) the curve is a lot different. Power and progression is better. I also switched away from my .7 ohm dry coil and but in a Lucas wet coil, I think a DB110. Running real nice.
What an adventure for a weekend..........