Problems with starting the engine after filling carb with oil and topping up oil.

[77LotusEclat]

I bought a 1977 Eclat back in September. When I got it home we managed to start it up with a new coil installed. One of the carbs were dry (Zenith Stromberg), the engine started with no effort. Then I filled the dry one and topped up the oil. Then for some odd reason the following week it didn't want to start and it cranked very slow. It got spark, fuel (smells it in the cylinders and sparkplugs are wet), rotor is good, spark housing is good. When I tried to start it would not fire. Starter is ok. Also it fried the green wire for the negative pole on the battery, and I mean FRIED it, so I turned off the ignition and cut battery power. When I later tried again it blew the 1st fuse (top) in the fuse box 3 times, replaced 1 by 1 and blew all of them. Any idea what caused this? I assume there's a short along the green wire from the battery somewhere, and have to locate it, but I don't understand why it didn't start the 2nd time we tried. The new coil were there on both attempts (need new spark plug wires due to mice destroying the silicon layer on some of them). Have read a bit about the Lotus engine in other forums and many seem to have problems with these engines (907). Also this car have been imported from the USA and they have done a crazy wire tangle in the center console by putting all the gauges in there and it's a bunch of red wires going to and fro all of the gauges....an American custom nightmare failure! Not sure if it's a Federal or domestic edition. Anyone know the difference, because I don't.

[Escape]

A green wire is normally ignition switched and fused 12V feed, so shouldn't be connected to the battery negative. Unless you want to blow fuses.

Of course if the wiring has been messed with, there's no telling where the problem might be. The 9## engine is pretty simple and robust, you just need to work methodically and make sure everything is in decent shape.

[77LotusEclat]

I see in the picture it's connected to the positive pole. 
Planning on changing all the wires due to the mix of different reds in the system and missing EC components. Sourcing the internet for reasonable harness wires.

If anyone have a picture of the wire connections on the coil I would be very greatful. There's 1 wire I just don't remember where it was connected.

[EXCEL V8]

Hi Asmund - welcome to the forum!  Looking at your photos I think I'd start by rewiring everything!  Most of the original wire colours are available - usually in thin-walled cable.  Let us know how you get on!

Pete

[77LotusEclat]

That is my initial plan, have already contacted companies that make auto harnesses in order ot get a new modern one.

Only thing now is to find out if it's a non-federal, domestic or European wire harness in the car. I guess there are a few minor differences. This is a LHD from USA, with minor shortcuts in the harness and removed AC and radio and some crazy instrument customizing in the dash and center console. The first thing I have noticed is the crazy wire web on the back of the center console to all the switches and gauges. Then I found they had changed the color of the (brown wire, if it's even going to be there on this car) from the positive terminal to the rear fuse box, but I don't think that electric chart is correct for my Eclat since the chart is for late series 1. Then there's 3 for the Elite, 2 non-Fed. and 2 Fed. and 3 Elite late series 1, electric diagrams/charts. The question is which one do I use? The 3 remaining is for RHD cars. Been thinking of splitting up all the different end with their own fuse so it's easy to find the broken link whenever that happens, since there's basically only 7 fuses to all the different components. Anyone have wire diagram for Eclat 1976-77-78 models?
Think the easiest will be to rewire the whole cars electrical system.

Edited December 5, 2022 by 77LotusEclat

[EXCEL V8]

I'd be tempted to gradually build your own harness and include some more relays for the lights/heater circuits etc. - the switches carry too much current and tend to fail as a result.  A modern harness with thin-walled wire would be an improvement but I think you could do better, unless you really would like to keep it as original as possible.

Pete

[Dunc]

Slow cranking and a melted wire would suggest an earthing problem or a faulty starter.

Random left field thought....

I once did an oil change on a mates nova 1L, and only ever having worked on engines of a proper size, put far too much oil in it. The result was very slow cranking, as the crank was immersed On 907's, the dipstick tube can break, allowing the oil level reading to become ridiculous. Did you perhaps over fill the sump?

Probably not the above, but thought it worth mentioning.

Also, I recall an issue on a Volvo 244 with a stromberg carb whose rubber diaphragm split. Car wouldnt start - took a long time to find that issue. Wouldnt affect the cranking speed however.

 

Good luck with tracing it.

[Mike C Sailor]

I suspect an earthing problem and very, very strongly suggest you check and service the engine earth strap  before cranking again. Preferably renew it and in any case, clean the contacts, assemble and rustproof with waxoyl or grease.

If this earth is not good, several hundred amps may try to find a way to earth via say clutch cable, throttle cable, LT wiring, whatever; the risk of fire is substantial.

I renewed mine and added a second to different points for safety.

[77LotusEclat]

Will most likely change the whole harness and try to use similar color coded wires. Maybe just get hold of a wreck and use the wire from it to rebuild the one in the Eclat.

Have also contacted several harness manufacturers asking if they can make a new harness using similar colors as the original.

On 06/12/2022 at 11:17, EXCEL V8 said:

I'd be tempted to gradually build your own harness and include some more relays for the lights/heater circuits etc. - the switches carry too much current and tend to fail as a result.  A modern harness with thin-walled wire would be an improvement but I think you could do better, unless you really would like to keep it as original as possible.

Pete

Maybe just getting a wreck and use the harness from it and modify to modern fuses and relays.