Starting Problems and overun when switching off!!!

[nico506]

Hi all,
Just started the process of trying to get the engine started after some 4 years of getting the car rebuilt.

I have done the following:

Set the timing to 10 degrees BTDC

Checked fuel to each pot by removing plugs and also checked fuel via carbs via banjo connections- sprayed everywhere when turning over

I have optical lumenition kit fitted to dizzy and set up timing as per instructions.

I have sparks to each cylinder

I have changed coil to non ballast resistor type

Compression to each pot is as per book 160 PSI


The problem is that the car turns over fine, floods with fuel and fires but never catches, and backfires occasionally.

Then when ignition key switched to off the engine twitches on &off - overuns so it seems.


I think it is the timing and wonder if anyone has any problems similar to this as I keep checking everything and keep drawing a blank

I know this is a common thread - but mine is with a difference

Thanks in advance

[david.g.chapman]

Forgive me if you have already done this, but make sure you have the plug leads in the right order.

I got this wrong once and the engine can make all sorts of explosive noises without rotating more than a few degrees

Dave Chapman.

[ppnelan]

Are you SURE your timing marks & valve timing are correct i.e. no.1 cylinder at TDC on compression?
Is the distributor advance mechanism OK?
If it floods with fuel, are the chokes stuck on?
It can 'twitch' when the ignition is switched on & off IF the distributor is lined up ready to fire a plug AND there is a good enough air/fuel mixture in that cylinder. The switching action can trigger the ignition module to generate a spark.
Are you sure you have removed all 'plugs/bungs' from inlet AND exhaust ports etc? I left some newspaper in once and it didn't like it...

Matthew

[rgh0]

Nico

If you changed the coil to the non ballast type did you also change the coil wiring to suit a non ballast setup.

It sound like you have no volts to the coil when cranking and only volts when you switch off the cranking hence the "kick". The ballasted coil has 2 supplies, one that bypasses the ballast during cranking and one that was through the ballast when not cranking. You need to rewire a single supply that works in both situations to the non ballast coil

regards
Rohan

[nico506]

Thanks for the replies - very helpful- but can anyone tell me how to wire up the coil and solenoid to provide this additional power supply and ask whether I need to change the solenoid switch - to what type as noted in Brian Book

thanks for help - gives me some direction

Nico

[Frank Howard]

I have changed coil to non ballast resistor type...The problem is that the car turns over fine, floods with fuel and fires but never catches

Nico,

The way the car was wired at the factory, there were two wiring routes to energize the coil. When the key is in the start position and the starter is cranking, the solenoid sends 12V to the + side of the coil. When you let go of the key and it goes to the on position, the 12V connection between the solenoid and the + side of the coil is broken. Instead, 12V goes from the ignition key switch through the tachometer to the ballast resistor where it is changed to 9V. The 9V comes out of the other side of the ballast resistor and goes to the + side of the coil.

Sounds like you disconnected the connection between the ballast resistor and the coil. If you did that, while the coil will get 12V when cranking, it will get nothing as soon as you stop cranking and the key snaps to the on position. With your new non ballast resistor coil, you need to get 12V to it both when cranking and when the key is in the on position. Disconnect the white wire that goes from the tachometer to the ballast resistor at the ballast resistor and connect it to the + side of the coil. Let us know if that does the trick.

[nico506]

I am still not having much luck trying to get the car started-

As suggested by all-

I have chanegd the solenoid to deliver feed to coil as separate feed (blue /white) and installed ballast resistor to coil with white wire fitted to ballast from the tacho.
The voltages measured are 12v from solenoid to coil is 7.9v and 12v from tacho to coil via tacho.

I have a purple wire fitted to - side of coil from lumention module.

I have checked the spark at the plug end and it is very weak -should be fat spark !!!!

Plug leads are correct way round


Coil body is well earthed.

Looking at various books and diagrams- I am getting confused as to what wiring schematic to coil is correct

Brown/Yellow to + side coil?

White on - side of coil

White to + side of coil via Ballast resistor

Could someone tell me what is correct


I enclose some pictures to illustrate the set up I have and hopefully - spot the difference competition time ?????

No prizes - just lots of appreciation for this forum


Thanks for help

[types26/36]

:Looking at various books and diagrams- I am getting confused as to what wiring schematic to coil is correct
][/b]

Nico, have you had a look at this link, if you click on the pics the wireing colour is shown.
http://www.lotuselan.net/publish/lsb_co ... coil.shtml

[JATLAN4]

Sorry for stating the obvious but this sounds like the timing is 180 degrees out - I've done it myself and spent ages looking for a complicated solution to a simple problem. Is your TDC really when valves on cyl1 are closed?
John

[iain.hamlton]

Nico,

I have just got my +2 running after having a very similar problem.

A few things to look at.

1. Is the luminition compatible with the ballast resistor? I took my Ignitor off, returning to points, while i was trying to get things working. I dont use a ballast resistor either.

2. I had a fault on the solenoid to coil connection. Although it ohmed out OK, it worked better after I tightened the spades up. Remember if the connection is slightly intermittent it will "fire" the coil early, preventing you from getting a a proper spark.

3. My timing was way out. When I turned off the ignition, I was getting a "woomp" as the coil fired wherever the engine was at that moment. The engine would never start like this. I redid the static timing from first principles (set the crank to 10 or 12 deg -check it is on cylinder one. exhaust cam lobe on no 4 looking through oil filler cap faces the middle of the car - turn the distributor until you here the click as coil produces high voltage - then insure the the rotor arm faces the plug-one lead.

4. My timing light had stopped working, leading me to think i wasnt getting enough voltage. A coincidence. Very confusing and annoying.

I havent found what originally prevented starting. i suspect the Ignitor, which Aldon have agreed to test for me. I'll send it when the mail here is back to normal.

All in all, this was difficult and trying. i thought I was going mad.

good luck, best regards, iain

[nico506]

Thanks to all who helped me sort out the problems with starting etc

However I have a few issues:


Compression test
I get 160 to cylinders 1& 2 but 140 to cylinders 3& 4 - should I be worried.

Oil Pressure is 40-60 PSI hot.

However, when engine is turned off and rests for a while - I get a small water leak (coolant) below the engine directly below the clutch slave cylinder area and can't trace the leak - heater matrix & hoses seems dry as is all the hose connections.

No leaks visible from head /block mating joints?

No apparent leaks fro heater valve body or temp sender connections.



Any ideas please - comments much appreciated

Thanks

Nico

[types26/36]

when engine is turned off and rests for a while - I get a small water leak (coolant) below the engine directly below the clutch slave cylinder area
Nico

Nico, There is a welsh plug/core plug/freeze plug on the back of the block, it is behind the flywheel inside the bellhousing, has it been replaced lately?