I just finished a three-part series about shimmed valve adjustment in my 1974 Lotus Europa Twin-Cam Special. You wouldn’t think I could get a fourth article out of it. And you would be wrong. After all that work, it didn’t start. So today we’re going to troubleshoot.
The very word “troubleshoot” implies that you don’t know what the cause is—that is, it’s not like a leaking hose that you can clearly see needs to be replaced, or hearing your brakes let out a metal-on-metal squeal and knowing that you need to buy pads and rotors. And the funny thing is that the more vexing the problem is, the less likely it seems that you have a true “Eureka!” moment at the end. I’ve thought long and hard about this, and I think that the reason why is because, instead of being blown away and wonderous at the mechanical and electrical processes that caused the problem and your deductive skills that fixed it, your reaction is instead “THAT? THAT was the cause? I should’ve thought about that weeks ago.”
Read the full article on Hagerty.com: https://www.hagerty.com/media/maintenance-and-tech/the-rare-eureka-moment-when-troubleshooting-final....
I understand where your coming from, its frustrating when everything is "OK" but it wont run. Had a similiar situation with a sheared pin on a dist gear that held just tight enough to appear normal. Luckily the oil idiot light helped out when it wouldn't go out either. Yup, patience is a worthwhile virtue, it saves you from pulling out all the hair from an already balding head. Great article, well written!......Bernie
Two days ago I had a similar "Eureka" moment with my Ferrari 360. I had a rough idle, which in 360's > MY 1999, is particularly dangerous since it can destroy the precats in the headers. The problem was intermittent and didn't rear its ugly head in my garage. I chased this issue for nearly a month before the rough idle became consistent enough to throw an OBD code. No CEL, just a "last" code. Once I knew what cylinder was causing the misfire, it was a fairly easy thing to chase down and fix. Turned out the COP for that cylinder was erratic and replacing it fixed the problem. Quite satisfying in the end but frustrating to find.
Best thing I've read on the internet in quite a while. I ran through something similar. A hard starting issue that I attributed to a faulty fuel pump. Replaced the fuel pump and all was well. Until the second attempt to start. Couldn't be the fuel pump because it was brand new. Ran through every other component in the car, oil, air, ignition, compression... Finally as I gave up and retested the fuel system for the I realized the integral check valve in the new "good" fuel pump was not "good".
Replaced the automatic truck opening mechanism in my 2008 MB E320. Two pins on the original sheared so the motor and gears will spin when the key fob button is pushed, but without the pins there's nothing to engage the truck lock.
Installed the new unit and went to test. Nothing. The key fob will lock and unlock the car, but will not pop open or lock the trunk.
Go to you tube, trace schematics, drink a beer, go to bed.
Don't know why but over night had the thought to check the key fob battery; 2.9 VDC, spec is 3.0.
Amazon next day new batteries arrive. Trunk now opens.
Beware the cryptic incomplete incoherent, and sometimes just plain wrong Lotus Europa Workshop manual. And then as Miles Wilkins once said: "I can't tell you everything about these cars; otherwise, there wouldn't be anything to me to do." There must be be some "magic" to make things compelling.
Rob, Thanks for these articles. You make my mistakes - and the successes - feel better. The investigative process is all part of the fun (and frustration) but victory is so sweet when the engine fires up and comes to life.
Rebuilt 1997 M3 engine. Fired it up and noisy ticking sound at front. I replaced lifters, checked the main and rod bearings. Checked under valve cover many times. Finally, I looked at the secondary chain tensioner. It is an alum piece with an alum piston. It was completely worn out. It was also about the only thing I had not replaced and I had taken it off and on many times while troubleshooting. It was about $50.00 and took half hour to replace. Noise was gone. Also I bought my son a different car to use for traveling across the country, $7000+. All for a $50.00 part!
Reading the story of your travails with your little Cozzy brought back memories of the overhaul I did on my 66 Elan. Like you I had a bit of a struggle shimming the valves after my head came back from the machine shop. The previous wrench had solved the problem of not having the right shim. I found pieces of feeler gauge used for shims. Luckily I had a Ferrari mechanic pal who had most of the shims I needed and a tool to grind shims to the needed thickness. Finally sold my little rocket ship after doing a 360 in the rain on a crowded freeway. I knew I would kill myself in that car. Still miss it.....
I'm glad I wasn't the only person to think about that one because on every other engine on the planet the CRANKSHAFT spins at double the rate of the cams. Every morotcycle (OHV and OHC), car, jet boat, etc., that I have worked on, all operate the same way, cam, or cams, slower than crank.