Cant get the old girl started.

C

Chris_

New Member
Right just a couple of questions, i'm kinda new to all this carby stuff. More at home with EFI really.

If i take the fuel line off the carbs, should i be getting a decent spray of fuel when cranked or does it kinda spurt gently?

How big is the reserve supply, I'm guessing this is just a second, lower, fuel pickup. Right?

Are there any particular weak points on the ignition side of these engines? i dont seem to be getting sparking at the plugs (when i sit one on the rocker cover) Do these lucas ignition coils brake down over time?

Mine seems to give a weak, intermittent spark when you stick a plug in the king lead. But a spare ignition coil from a 1989 BMW seemed to produce a fatter more consistent spark at the king lead, but again nothing when i connect it all up and try a plug lead.

Any suggestions, or info, hugely appreciated.
Chris
 
Hello Chris,

The fuel pressure delivered by the pump, be it mechanical or electronic, will be in the order of 3 to 5 psi. This is all that the carburettors require, and will always be more than adequate.

If you are a little concerned on the rate of flow, replacing the fuel filter, which is a 12 month 12,000 mile affair is a good place to start.

You are correct, the reserve fuel line drawers from the bottom of the tank through a gauze screen.

The original Lucas coils, certainly in the case of mine as fitted to a 1974 P6B are a 16C6 type. Mine is now 35 years old and has never given me cause for concern. Does the distributor still have points fitted?

The original Lucas leads are a carbon core design, and will break down over time, so replacing with a set of Magnecor leads is always an excellent idea.

Ron.
 
Hi Chris.
Lets see what we on the forum can do for you!!
How long since it was started and ran OK???
First, make sure you have a fully charged good battery!
Bung in a few galls of fresh fuel!
Remove and clean the plugs one by one so you dont get the leads mixed up!

"If i take the fuel line off the carbs, should i be getting a decent spray of fuel when cranked or does it kinda spurt gently?"
It should be a good strong pulsing flow!!

"How big is the reserve supply, I'm guessing this is just a second, lower, fuel pickup. Right?"
Correct and reserve is about 2 galls,once youve pulled the resv lever out,but the tap on the pipework could be siezed!!

"Are there any particular weak points on the ignition side of these engines? i dont seem to be getting sparking at the plugs (when i sit one on the rocker cover) Do these lucas ignition coils brake down over time?"
Only the normal stuff!! With some emery,lightly clean the points,check the gap,clean the rotor tip and pick up tips in the dizzy cap.

"Mine seems to give a weak, intermittent spark when you stick a plug in the king lead. But a spare ignition coil from a 1989 BMW seemed to produce a fatter more consistent spark at the king lead, but again nothing when i connect it all up and try a plug lead."

A tip to "hot wire" the ign system is,find a permanent live,"thick brown wire",run a lead from that to the side of the coil that doesnt go to the dizzy.this bypasses the starter solenoid!
Then give it a good crank over with about 1/2 choke.
I once put some fuel into a squirty bottle and while a mate turned the key and opened the throttle, gave a good few squirts into the carbs!!
Put the batt on charge tonite,and see what happens tomprrow!!
good luck!
Dave
 
Funny you should say about the squirty bottle :oops: It's great for starting 2 stroke boat engines :D

Maybe i'll trust the coil a little further if they are fairly robust.

As for your questions Mr Pilkie:
I dont know when it was last started, but a little more than 2 years ago i think. (mind you, tax in the window for 1992 :( )
Fresh fully charged battery
I have put about 10 liters of new fuel in, and cleaned up about half the plugs.
Cleaned up the points contacts (yes it still has them) and the dizzy cap contacts.

I'm wondering now if the fuel reserve tap may not be working as you say, the fuel line pumps but it is not a steady flow of any sorts, just a bit of a spurt at the end of the stroke.

Oh, one more thing, fuel filter. Is that in the engine bay, little creamy coloured canister about 12 inches of pipe before the fuel goes into the carbs?

Right, lets go and figure out how to upload pictures. :D
Cheers
Chris
 
Hi Chris,

Fuel filter....


Good luck with getting her going!

Cheers,
 

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What year is it and what type of carbs have you got?
The remote,bolted to the side of carb fuel pot,or the square bottomed carbs!
It could well be that as it has stood so long the fuel has gone well off,and that will have left a crystallized goo in the carbs fuel chambers,causing the needles to seize up,also in the fuel pump,and in the fuel lines.
You may well have to strip the carbs down,and the fuel pump and give them a real good cleanout.!! A gallon of fresh fuel in a bucket,and an artists stiff long brush does a good job!!
Blow air into the pipe on the input side of the pump to blow back into the tank helps clear it out!
If you squirt neat fuel into the carbs with full throttle,and it just about starts up,that would point to a carby problem!
When I brought a 2200tc back to life,I poured an eggcup full of neat fuel in through each carb to prime the pistons with fuel! It popped and farted a bit then started and ran for a few secs till the fuel was gone,did it again,and then went in with the squirty bottle to maintain tickover for a while to help try to bleed any air out of the system!!
Have fun!! And dont smoke!!
 
Wow, i'm not used to responses this quick on a forum.

This is my engine bay.

P1060190.jpg


Which is a pair of SU's? all integral?

The car is a N plate 1974. 3500S

The little bit of fuel i got out of the lines, when i was first checking flow was not very unleaded coloured. Very old and stale i reckon, hence the new fuel in it.

A good spray of neat fuel down the carb throats whilst cranking didn't provoke any response from the engine which is kinda why i'm focusing on the ignition side for now.

Is there any easy way of getting to the jets/needles to check them out.

At the moment the car is on a trailer in a storage plot in a field, i cant get it home until its running and move able under it's own steam as it will have to move about every now and then as i'm short on space. So i'm just collecting ideas to get it to start. Then i can get it home and get to cleaning and refurbing.

Chris
 
The 2200tc I revived had that type of carb on,and I had to remove them and strip them to fully to clean them out!! It will be almost impossible to do it in situ,and really is easier to remove them and do it!! Ive had to do it on mine!!
And,due to a sticking needle, at the roadside on my hols as well!!
It can take a fair bit of cranking to get things going again!! You could also give it a compression test just to be sure there is pressure and suction being created in the bores!!
Its just a matter of methodically working it through until you find the problem,or it decides it wants to start up after its slumber!!
Do you know why it was laid up all those years ago???
 
Hi again Chris,

If you're not getting a spark at any of the cylinders it would suggest the problem lies somewhere up to and including the dizzy cap. As Dave (pilkie) suggests the usual suspects are the points, rotor arm and cap contacts. The system incorporates a ballast resistor in the loom, which is bypassed on cranking to give battery voltage to the coil. Once started, normal running LT voltage will be somewhere between 6V & 9V. The coil primary resistance should be around 1.5 ohms.

Have a look at this flowchart for a start..

Troubleshooting Lucas Points Systems
 
When you squirt fuel into the carbs (please be careful doing that - ask my brother!!) did you lift the pistons?

When you do this with your finger it should be a damped but smooth operation, and it should come back down on its own slowly and smoothly. If not, unscrew the black knurled knob on the top of the carbs and drop in some 3:1 oil, up the the bottom of the thread. Careful how you put them back as it is easy to cross thread them. Move the pistons up and down with your finger until they are smooth. When you move them up you will see the needle in the centre of the piston, going downwards into the jet.

You need to check the voltage on the positive side of the coil. It shoud be 6-9V with igniton on and 12V whilst cranking the engine. Also check the voltage on the negative side whilst cranking. It should go from 0V to 12V rapidly.

One way to check you have fuel at the needle is to crank the engine whilst looking into the venturi (Remove the HT lead from the coil to the dizzy whilst doing this in case it tries to start and back fires.) You will see the piston move upwards slightly and there should be a spray of fuel at the base of the needle going into the engine.

Let us know how you get on, and please be careful with petrol. My brother was squirting petrol into his carbs (Never a good idea with sidedraughts) and some of it inevitably dripped out onto the exhaust manifolds. One of the gaskets was not too good and when it fired, it set light to his whole engine bay. He also lost one of his eyebrows and part of his beard.

It wasn't funny - well not for him. The rest of us laughed ourselves silly 8)
 
Yeah, i'm always careful with petrol in spray bottles. I watched a con rod shatter the side of a two stroke, two pot engines crankcase once after the owner decided to fill the bores up with fuel before cranking it over. I guess it was still in there burning when the piston came back up.

Pilkie: as far as i know, the story goes that the first owner was going to get rid of it (scrap) and the bloke i bought it from bought it to save it from the scrap heap. drove it around for a couple of years and then had the idea to restore it. But never really got round to it so it has just sat around waiting for this restoration.

vaultsman & quattro: I am getting those sorts of voltages on the coil, and i've got power traveling across the points when they close so i think the actual electrical side of it is mostly alright. Just all covered in crud. Time for a good clean up i think.

Oh, i dont think i'm getting that high a resistance across the primary side of the coil i seem to remember it being just off 0 Ohms which i thought a little odd at the time, but i'll have to check.

Thanks again for all your help and info, hopefully one day i'll be able to help someone out with what i know.
Chris
 
Agree with dizzy cap / rotor arm. Wifes 800 died at a roundabout, traced it to a failed brand new rotor arm, same symptoms spark at king lead, no spark at plug leads. Rotor had broken down and was earthing out.
 
Yep it eventually came down to manky fuel, and different brands of cap & Rotor not touching in the middle.

Gave the carbs a good clean up, ran her for a little from a jerry can, pumped plenty of 'yellow' petrol out of the lines, and shes running lovely.

Now just gotta give it a good service. :oops:

Cheers For your help, I'll be back with more dumb questions later.

Cheers
Chris
 
Good to see that you got it going :) I would be a little concerned at the lack of a nice strong spurt of juice from the petrol pump it may be the pump is in need of some attention also.

Graeme
 
No, pump seems to be pumping quite well. Just what was coming out was quite manky.

Give a good 'glug' every couple of revololutions.

Now just got to track down a good used clutch master cylinder. Seems to be the problem that is stopping her moving at the moment :roll:

Roll up roll up, the next big problem he he.

Chris
 
I am about to list a clutch slave and master on ebay. Brand new, fitted to my 3500S, ran around yard, and far too heavy for my conversion, so whipped off and am running SD1 Master and slave. From memory the master was about £90 and the slave £30. Make me an offer if you interested. Both are new and for the V8.
 
Chris_ said:
Now just got to track down a good used clutch master cylinder. Seems to be the problem that is stopping her moving at the moment :roll:
Chris
Click to expand...

Hi Chris,

Great that you've got the engine running. What's the problem you see with the clutch MC?
 
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