Lotus Elan

Non starting / very poor running +2s

PostPost by: Gizze » Sun Aug 14, 2005 6:52 am

I've replaced the water pump, and since this had real trouble in getting the engine to run properly. Before carrying out the work the engine ran reasonably well.
Timing: I've checked the compression ratio (thinking that maybe I'd messed up on the valve timing) but this is at, or close to 160 psi on all cylinders, so I'm assuming that this must be ok? I've statically timed the distributor to 10 deg BTDC.
Fuel: I think the carbs (Webers) aren't well balanced because after trying to start the engine and flooding it, the back two plugs are very dry compared to the front two. However the car ran before the work and I've not adjusted anything on them.
There's a spark at the plugs but it might be a little weak, so I've ordered new cap, leads, condenser, and rotor arm. Removing one plug at a time doesn't seem to affect the running of the engine - it's that bad!
When it does run, it's very lumpy, and misfires badly, and at the moment it won't even start!
So, my question if anybody could help me is:
1. Is there anything else I should be checking / adjusting?
2. Could the valve timing be out, even though I'm getting an acceptable compression ratio?
3. And lastly, is there a good mobile mechanic that anybody has used near Southend on Sea in Essex?!
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PostPost by: nebogipfel » Sun Aug 14, 2005 10:01 am

You seem to be getting a bit confused about valve timing/compression/ ratios etc......... nevertheless ....

The important thing is that if you have 160psi on all cylinders then the compressions are fine.

You need to go back to basics.

1. Put the timing marks on TDC and recheck the valve timing

2. Make sure that number one cylinder is on compression stroke (the valves are closed) and then ensure your ignition timing is set at 10 degrees before.

3. Make sure that the firing order is correct and that when you checked the ignition timing the rotor arm was pointing at number one cylinder in the distributor cap. (remember direction of rotation)

This is all assuming that points, condenser, (if you have them) rotor, cap and leads are all in good condition!

If you still have problems then it is likely that rolling the carbs around may have disturbed all the semi solid debris collected in the float chambers and distributed it through various jets/drillings. In which case a bit of time and one of the aerosol carb/choke cleaners should do the trick

I wouldn't get too stressed about carb balance at this stage, your problem sounds much more fundamental!
John

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PostPost by: types26/36 » Sun Aug 14, 2005 11:58 am

Assuming you have the valve timing marks correct and the ign timing at 10 degrees BTDC then I think you have disturbed the balance between the two carbs, this is easily done as the carbs are flexible mounted.
By removing and refitting the carbs it is unlikly you have got the carbs in the same position (relative to each other) as befor, check with a pipe if both carbs are sucking about the same, hold the pipe to the carb air inlets and listen to the hiss, adjust the spring loaded balance screw between the two carbs until both sound about the same.You may also have to adjust the idle screw as well.
You can get it to a reasonable setting by ear but not to the exacting standards that have reasonantly been discussed on this forum.
Brian
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PostPost by: types26/36 » Sun Aug 14, 2005 12:35 pm

Just re-read your post and reliesed you haven't got it running yet :oops:
so you can't listen to the carbs, I agree with previous post go back to basics and recheck valve timing/fireing order/ign timing etc.
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PostPost by: zuckerlowe » Mon Aug 15, 2005 1:55 pm

Hi Gizze,
I've had this problem in the past when I haven't used the car for some time. Try replacing the fuel. Modern unleaded goes off very quickly. Usually I can get away with pouring fresh fuel into the Webbers via the jet cover and it will start but runs very rough until I can dilute the old fuel. I tried a whole host of changes, leads, plugs, coil etc but just replacing the fuel is the one that worked.

Cheers
Steve (1968 +2)
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PostPost by: nebogipfel » Mon Aug 15, 2005 6:04 pm

I know it's a b*gger of a job to do a Lotus water pump but it shouldn't take so long that your petrol turns into varnish! :D
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PostPost by: Gizze » Sat Aug 20, 2005 6:31 am

Many thanks for all the advice - finally get her running with something resembling what it should - still I suspect needing some fine tuning but a whole lot better than before.
Re checked all the valve timing etc and except for the fact that the pitch on the chain meant I couldn't get the crank sprocket exactly where I wanted it was all ok. Then fitted new distributor cap, leads, condenser etc etc.
Although in a way at this stage a small fire and an insurance claim to write the car off would have been quite welcome I decided to change the petrol hose because this didn't look to be in a very good condition. Now there was no petrol in the hose! I hadn't had this before as previously there were obvious signs of flooding after trying to get the engine to start. Anyway after some initial turning over the engine ran, and on restarting after waiting a couple of minutes started straight away. So maybe what looks like a new fuel pump isn't quite right because the petrol seems to have drained back past it.
So finally a conclusion: problem appears to have been electrical, but masked maybe by the fact that petrol was not always there if I'd left the engine for a while. Life's never simple!
Anyway now I'll tackle the other few remaining jobs and hopefully then it'll be the open road - can't wait as I've only driven the car 50 miles on the day of purchase.
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