88 tb42 Mav won't start!

[BLKWDW]

My brothers got a problem his tb42 carb engine. Its starts anytime of the day fine on first start up but once it's warm it won't start again after u turn it off. What causes that?

Edit: as of yesterday arvo car won't even turn over. Turn key and nothing. Battery is at 12.6v. Turn key and voltage doesn't move.

It started fine yesterday 1st go drove a couple km to shop. Then wouldn't start. Would wind over but not fire. Car started fine when I went to give a hand to clutch start it. Now won't even wind over. Checked fuses and all good.

[garett]

try checking the voltage to the starter motor. both wires one will be the trigger so get someone to try and crank it over while you check that one. other wire should be constant 12v.

if no rigger voltage or low v check the ignition switch could be burnt contacts in the switch. if you have 10 v or more on the trigger probably the solenoid on the starter.

was it turning over when it wouldn't start before?

[BLKWDW]

Yeh at first it was starting fine 1st thing in the morning but if he went to the shops or somewhere when he got back in to start it, it wuld turn over but just not fire. I clutch started the car last time it did it and drove it home but when we got home and turned it off and went to turn it back on again nothing. Not even a click click like a dead battery. Battery reads 12.6v now and was charging at 13.88 when we got it running

[garett]

i run a diesel so not 100% on the petrol system they use. but i have run some carbs, if you can see the float level should be half way. and check spark is it weak strong or not there at all. but before all that it needs to turn over. no security systems ?. check your powers start at the starter motor work back to the ignition switch.

you ever used the screw driver trick to turn the car over ? touching the two terminals on the starter it should turn over (be careful it can spark ect). if this works it confirms a triggering issue, common fault is the ignition switch burning the contacts inside it, some can be pulled apart and cleaned up. if it doesn't work try tapping the starter might help but it sounds more like its no longer triggering the starter motor solenoid. if you have a voltmeter check the v at the trigger wire if it's below 9ish v common fix is to add a relay to boost the voltage.

have you tried wiggling the key about while trying to crank it over ?

hope this helps

[threedogs]

Re-do the battery terminals after giving them a once over with a green scourer.
Re-do the earth strap as well.
Does it make a clicking sound or nada when you turn the key?

[BLKWDW]

Can't see how there would b a fuel or spark issue as it could b clutch started and ran fine when it was going.

Cleaned and re attached all the terminals.

Didn't try wiggling the key.

Will try the screwdriver trick when I get home next.

Doesn't make any sound. Turn key and nothing.

Does the carby engine run a crank angle sensor?

[garett]

its either a ignition module or points not sure on this engine some one else might be more accurate. if you open the dizzy and can see a little spring leaf pressing onto the main shaft under the cap its points.

[BLKWDW]

Upgraded the points to a Petronix ignition setup

http://m.ebay.com.au/itm/Pertronix-Electronic-Ignition-Kit-Coil-for-Nissan-GQ-Patrol-TB42-58725905-/221563123279?nav=SEARCH

[garett]

ok that is the bit that does the work of your crank angle sensor. if it is faulty it may work while its cold but fail when it gets hot.... why it can run fine on first start but won't fire when warm (never seen one stop it from cranking) . thats why i suggested checking the spark after the cranking is sorted. it seems to be having 2 different problems.

sorry my mind has already gone on holidays but at a guess from what you've written id suspect a ignition switch for your cranking issue or lack there of

[taslucas]

If it's not cranking then it could only be the starter motor couldn't it? But that doesn't explain why it cranks but doesn't fire other times...
As Garrett said above, it appears to have two problems.
Sometimes if a coil is damaged it will fail once heated up

tappin from tassie