Lotus Europa Forums > Garage
Hard starting...timing issue?
jbcollier:
If you set a Stromberg car to 5° static, it will have a total advance of 19° and run very poorly indeed.
EuropaTC:
Hi Bryan,
When you mention a Pertronix distributor, is it a brand new one supplied by Pertronix to their spec or the original one with Pertronix ignition replacing the points ? If the former then I guess my first thoughts would be around the advance curve they have fitted.
When Lotus had Strombergs in the UK Elans they had a 40953 distributor which came (according to Miles Wilkins) with 9deg static and 33 total advance. The Federal/European/ECE15 spec cars had a 41225A distributor with 5deg idle and 19 total advance.
If you have the Miles Wilkins book, he does a chapter on the distributor options with advance curves. There's also service bulletin issued in '73 mentioning the vac. retard unit and it looks like the static timing is 10deg dropping to 5deg at idle. If you don't have his book I can scan the relevent pages later today ?
If it all checks out then I guess the next step would be to make sure the advance/retard mech is working smoothly and returning properly. As for the carbs, I've only ever had Strombergs on one car and after a few years of hassle changed them so I'm not much help on the carbs themselves. Maybe a diapraghm split ?
Brian
Bryan Boyle:
--- Quote from: jbcollier on Wednesday,March 20, 2024, 07:18:06 PM ---A 4-port Europa TC is set to 12° at idle and has 14° of mechanical advance which gives a total advance of 26°.
A 2-port Europa TC is set to 5° at idle but it has a vacuum retard unit so the timings are probably similar.
I always start with valve clearances. Stromberg carbs (and SUs) are very sensitive to tight valves.
--- End quote ---
Well...I'd wager it's NOT the valves, since the starting issues seem to have come on in a couple days and has been starting and running reasonably well up to now. And even if it is, I'm not going to go down the road with this particular head since I have an overhauled head with the valves shimmed properly sitting on the side (well, on its end) waiting for me to pull the lump.
Going to fiddle with the timing (least cost option right now); Brian: it's the pertronix replacement (the original lucas was hacked apart to take the retard capsule off and the bushings are shot). The diaphragms are new (well, 2 years old) and were installed last time I pulled them apart. Like I said, it's been starting and running fine up until now...only the last couple times did it give me fits. I'll check the timing first next time I get her started; like I said, at 1000-1200 rpm, she's showing 15 degrees advance. I'll try dialing the dizzy back a bit and see. Easy things first before getting into a massive tear down.
4129R:
I bought 4 syringes from the chemist (honest I am not an addict) and use them to squirt petrol directly into the inlet trumpets of the 40DCOEs.
If that does not get at least some firing, I know the problem is on the ignition side.
Squirting ether sprays into the trumpets was getting costly, so I thought why not use petrol.
With engine timing, I use a strobe to get about 35 BTDC on about 3500 RPM and that seems to work. Anything less and I get misfires and bangs when I switch off.
EuropaTC:
--- Quote from: Bryan Boyle on Thursday,March 21, 2024, 05:46:45 AM ---Brian:
it's the pertronix replacement (the original lucas was hacked apart to take the retard capsule off and the bushings are shot). The diaphragms are new (well, 2 years old) and were installed last time I pulled them apart. Like I said, it's been starting and running fine up until now...only the last couple times did it give me fits. I'll check the timing first next time I get her started; like I said, at 1000-1200 rpm, she's showing 15 degrees advance. I'll try dialing the dizzy back a bit and see. Easy things first before getting into a massive tear down.
--- End quote ---
Ok, the diaphragms should be ok although we do seem to have issues with the quality of some rubber components and modern fuels over here and a split could give the "it was fine yesterday but today it's a dog" symptom.
Even so I think you're right to re-set the timing and see if that sorts it out. I have the older Pertronix which means I can set it static with a bulb, I'm guessing that option isn't so easy with your set up but you can always guesstimate a few degrees and see if it's easier to start. And once it's running you can get an accurate setting and see if it advances/returns from blipping the throttle.
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