New build - Won't Start

[satancom]

Right been fitting a v8 into my landy and after a dead starter I managed to get it spinning nicely today on the key. But no joy. any suggestions would be welcome

It could be one of 4 things I guess.. or worst case 4 of 4 things.

Fuel
Yup its present, and getting to the carbs, and no longer leaks out from the float chamber. So assuming the fuel is getting into the inlet then its fine. Can I Check this?

Compression
Well certainly takes some effort to spin by hand and made nice suck suck suck noises when being moved around, so fairly sure thats ok. It spins round rapidly enough on the starter

Spark
Well the dizzy is an electronic one (Opus) and is running on a 12v coil without any ballast resistor. I pulled one of the spark plugs and there was definitely a spark, but a little weak. Battery is on charge tonight as it was a tired one I have been lent while mine get a proper charge by sideez in his garage.

Timing
Well yes quite possible. The leads are all correct as far as im concerned. and at TDC the rotor arm is more or less on plug 1. Now I believe this is correct but will happily be told otherwise.

Whilst cranking the engine turns freely, the ful pump humms merrily, but I don't really seem to get much in the way of firing! Any suggestions welcome I worked from 5pm till 7pm in the rain and cold and dark. Im too tired to continue and would prefer to do this in day light so I can check for oil flow!

[katanaman]

to check if your getting fuel into the engine your plugs should be getting wet. You said TDC but have you timed it on the right one? There is an exhaust TDC and a compression TDC it needs to be on the compression one.

[satancom]

OK, I willl spin it up a few turns tomorrow and then pull the plugs to check for fuel. No filters at the moment so theres not much to complicate things.

With regards to the timing. I believe I have it on the compression stroke. When it was on the floor in my house I fitted the dizzy. Compression stroke would be no1 piston at the top of the cylinder with both valves closed, yes? If so then its timed 'near' to where it should be. I would have assumed it would fire and make some noise there!

The carbs are not completely connected up, I only have the fuel in connected. Should there be any other pipework connected for a test fire?

[ChrisJC]

Are you 100% sure that your timing is not 180 deg out on the distributor?

To check, lift the drivers side rocker cover, and turn the engine until both valves on no. 6 cylinder are equally open. At this point, cylinder number 1 is at TDC on the firing stroke. Ensure that the distributor will cause a spark in the next few degrees, and that the rotor arm is pointing towards no. 1.

Another option is to try to tow start it, that way you can spin the engine much more quickly than with a starter.

Chris.

[satancom]

Well it was raining last night which won't have helped matters, but it should be dry tonight so i can take the rocker off and check #6 to ensure the timinigs correct I will also leave the cover off to check for oil flow!

Tow starting isn't an option at the moment as in true land rover style the front brake cylinder hasn't enjyed being sat for two months and spat its dummy (well fluid) out all over my driveway!

And the clutch isn't connected yet either It needs a lot of finishing

I will let you know hoiw I get on, any other suggestions welcome Want her to start tonight!

Oh also, I have a ballasted coil, If I stick this one it should start easier? I won't run it to long as it will be connected to 12v supply and cook itself, but at least I will get a good spark during cranking? Good idea or not?

[Eliot]

180' out on the timing i suspect - was it popping and banging through the carbs?

[satancom]

Nope no noise! so slightly frustrating.. SO im starting to think the spark may be too weak ?

[Stu E]

Sounds basic, but i forgot to put the choke on when i went to start mine the first time with SU's fitted . Connected it up and it fired almost straight away.
HTH Stu

[ramon alban]

Hello Stan, observations in RED.

It could be one of 4 things I guess.. or worst case 4 of 4 things.

Fuel
Yup its present, and getting to the carbs, and no longer leaks out from the float chamber. So assuming the fuel is getting into the inlet then its fine. Can I Check this?

Squirt some fuel into the intakes directly and see of it fires.

Compression
Well certainly takes some effort to spin by hand and made nice suck suck suck noises when being moved around, so fairly sure thats ok. It spins round rapidly enough on the starter)

Have you tried a compression test?

Spark
Well the dizzy is an electronic one (Opus) and is running on a 12v coil without any ballast resistor. I pulled one of the spark plugs and there was definitely a spark, but a little weak. Battery is on charge tonight as it was a tired one I have been lent while mine get a proper charge by sideez in his garage.

Fat sparks are best, but even a small spark would give the odd pop and bang which sorta makes me think its fuel.

A poor battery when cranking might be down as low as 6 to 8 volts so it has to be a strong battery to crank a tight engine and fire the dizzy electronics and the coil.


Timing
Well yes quite possible. The leads are all correct as far as im concerned. and at TDC the rotor arm is more or less on plug 1. Now I believe this is correct but will happily be told otherwise.

This sounds a bit doubtful Firing sequence 18436572 with No's 4 and 8 nearest the radiator should do it.

Check the image on this link:

http://www.vintagemodelairplane.com/ima ... utor02.jpg

Timing about 6 deg before TDC. It it is retarded a fair bit it may not fire as the piston is descending.

Whilst cranking the engine turns freely, the fuel pump hums merrily,

Starting an engine from cold need a rich mixture so check the choke is working.

Hope this helps?

[satancom]

Squirt some fuel into the intakes directly and see of it fires.
I think I will do that on the weekend. As I believe this is the problem, the plugs remained dry through cranking.

Have you tried a compression test?
Nope, I can get a compresion tester if need be, but will do that once im happy its nothing to do with fuel/spark

Fat sparks are best, but even a small spark would give the odd pop and bang which sorta makes me think its fuel.

A poor battery when cranking might be down as low as 6 to 8 volts so it has to be a strong battery to crank a tight engine and fire the dizzy electronics and the coil.
Yes. I checked the voltage at the coil and it ws down to around 7 volts. I swapped the coil out for a ballasted one and the spark was much nicer. no pops or bangs though.

This sound a bit doubtful Sad Firing sequence 18436572 with No's 4 and 8 nearest the radiator should do it. Timing about 6 deg before TDC. It it is retarded a fair bit it may not fire as the piston is descending.

Ok timing is correct using the method detailed a little higher in this thread. Although I set it to TDC so will need to set it 6 degrees advanced

Starting an engine from cold need a rich mixture so check the choke is working.
Choke? hmm now there an interesting one. Don't think the chokes working as the throttle linkages are home made as RPI wanted £75 for the linkages... I will see if I can get them to work as they should.


Cheers for the advice, more welcome I'm a little pushed for daylight and time as im working on my driveway.

[Garth84x]

numbers 4 and 8 nearest the radiator.....?

mmm good job i read this as mine has no1 stampted on the inlet manifold
nearest the n/s/f

praps iv'e put the inlet manifold on back to front....


Garry

[satancom]

I took it to mean that 4 and 8 on the dizzy are nearest the radiator. The inlet manifold has no 1 at the n/s/f

[Garth84x]

oh...

new some new eyes......


Garry

[ramon alban]

Firing Order, Hope I didn't confuse too many people



Have added the image to the earlier post

Ramon

[satancom]

Well, I took the dizzy off and primed the oil pump with a 12mm socket on a long extension in my battery drill Did the job.

I then set the timing to 6 degrees before TDC and threw some petrol at the carbs. Vroom on the first turn of the key But then It wouldn't start again without more petrol in the carbs. So I wired the chokes open (need a linkage) and she starts and runs like a goodn.

Cheers for all your help guys, i can now continue with the plumbing.. My neighbours seemed to like the noise too