advice please on a toyota 3y engine intermittent fault

[poppa smurf]

I have a 3y, naturally aspirated, non electronic ignition completely old school engine in my camper

it has a strange fault......the engine will give a complete cutout for a millisecond,

I am pretty sure it is electrical as it happens too fast to be fuel

it is as if a kill switch is in place and a quick flick off and on takes place

I dont reckon it is plugs nor dizzy or leads or coil.......could it be a short

if so where?......anyhow.....ideas please

[zilo]

Ignition switch on steering column does it in some old cars...bounce around with a heavy set of keys and it will do that.

Have seen an earth strap rub against the 12v on an ignition coil over bumps do it as well on a skyline.

Also seen loose ballast resistor conections do it too..

[JimStone]

Loose mounting screw on condenser will do this too....

[poppa smurf]

ignition switch.......I give it a hammering, moving it from side to side and up and down, in and out with engine running, didnt miss a beat, I only have 3 keys on it, ignition, gas door and main house door

coil is well away from any wiring but I gave it a hammering with a nylon bannister broom and all wires coming too and from.....no miss

I cant see the condenser but I gave all wires a really good shake with no result

I found the inline heavy fuse, gave that a belting with no result

any wires I could find I gave a good shaking too....no result

I havent tried the batteries as yet but when i checked them a couple of months ago they were both fine (house and start).....battery isolator wires all tight

I'm out of ideas.....she goes in for a passenger side rear wheel bearing next week so I'll get the mechanic to have a look around

[supershifty]

Poppa, def sounds electrical. I'll have a stab in the dark and suggest you look at the wiring to the carby. This is pushing my memory. You should have a few wires running to it. One of them will run to a solenoid that shuts off fuel flow to the idle circuit when you turn the ignition key off - this helps to prevent "running on" or "dieseling". I wonder if the solenoid isn't getting a good electrical connection. You didn't state whether the fault occurs at idle or while motoring along. If it occurs both at idle and whilst driving along - then my theory has failed.

Cheers!

[poppa smurf]

Originally Posted by supershifty

Poppa, def sounds electrical. I'll have a stab in the dark and suggest you look at the wiring to the carby. This is pushing my memory. You should have a few wires running to it. One of them will run to a solenoid that shuts off fuel flow to the idle circuit when you turn the ignition key off - this helps to prevent "running on" or "dieseling". I wonder if the solenoid isn't getting a good electrical connection. You didn't state whether the fault occurs at idle or while motoring along. If it occurs both at idle and whilst driving along - then my theory has failed.

Cheers!

anytime, anywhere mate......idle or 100 kph......I checked the wires to the carby, well belted them with the bannister brush, nothing

if the thing would simply stop so I could do a proper test and see what is failing it would be better ...but this can happen anywhere, anytime

it's not really a worry but simply an annoyance ..."what was that" type of thing, it happens in a blink of an eye

then of course on a long trip such as our last one it plays on my mind, takes the enjoyment out of the holiday

a bloody nuisance more than a drama but one that must be found

[big_landau]

i had heaps of trouble with my last landcruiser,i spent thousands on that car and in the end i traced the intermittent fault to my brain.i made a mistake and will never own another toyota again,we even popped a bottle of bubbly when the dog was sold.never had a problem since and i feel great,oh what a lemon.

[poppa smurf]

this old girl has been anything but trouble....we've owned her so long that she is a part of the family

getting a bit long in the tooth now and a bit behind in technology but she's been around the block a couple of times with us and many forays into never never land

we have only needed to replace

alternator brushes

fifth gear and bearing after a big blow heading past the coorong and a road train coming the opposite direction that almost stopped us dead from 90 kilometres per hour

clutch, pressure plate and thrust bearing

clutch master cylinder

we've done 245,000 trouble free kilometres...only near drama was the alternator brushes failing heading into Halls Gap the back way at 10 o'clock on a Friday night, roos everywhere, with lights failing, due to be on the Melbourne ferry the following afternoon

I've had 3 Toyota's....all damn good cars with no breakdowns

this small annoying fault is minor and I'm sure once found all will be well again with her

[Peter B - CV8]

My money would be on the coil (intermittent failure). How old is the existing coil ???

[poppa smurf]

never had the coil replaced.....I thought they either worked or didn't!

I guess I could replace it and see.......I used to use the GT40's are they still around and are they suitable?

[The Yeti]

doesnt matter

[supershifty]

Poppa, let's say we've ruled out the carby electrics. That brings me back to the ignition side of things. Pull the distributor cap and rotor button off and have a good look inside where the wire goes to the points. The points are rotated on a plate actuated by the vacuum advance mechanism. Just lift that wire away from anywhere that looks it might me touching. Again mate - just another theory. Hard to say as I'm a 1000 miles away.

Yep, it's gotta be fixed - it might be just a quirky thing, but too late if you're stuck on the side of the road on an otherwise pleasant trip!

Big LOL on the bannister brush Poppa - I've got 1000's worth of hand tools, but a bannister brush is not part of my kit, must get one someday!

Cheers!

[poppa smurf]

righto I'll do that.....sounds like just the tricky little bugger that may be at fault

[Peter B - CV8]

Originally Posted by poppa smurf

never had the coil replaced.....I thought they either worked or didn't!

I guess I could replace it and see.......I used to use the GT40's are they still around and are they suitable?

Nah - they can play up (oil inside overheats). Go the GT40R (it's got the built in resistor so your radio doesn't pickup any whine & don't forget to scrape away the paint so the retaining clamp gets a good contact.

[poppa smurf]

okay i'll grab a newie tomorrow

[302 XC]

Check all earth connections
Over time they can get a bad contact or even start to break connection at the bolt or screw where they are connected to well earth points

Just undo whatever they are connected by, bolt,nut ,screw, scuff the electrical end and the body with emery paper
Being an intermitant miss here and there, its a wire somewhere starting to break connection,id try all the earth points first
These arent too dear for parts, so a set of plugs and leads wouldnt go astray either
Could be one of those also

[poppa smurf]

Hmm! all earth connections.....theres a job.....the distributor is up under the drivers seat and to even see the thing is a step to becoming a contortionist

but I'll have a look see

supershifty.....the bannister brush was a substitute for a piece of wood.....motor running and belting wires with a metallic object didn't seem to be the smartest thing to do

why was I belting wires?......I'm glad you asked....I cant reach most of them so I had to use an extension of some sort to make them jiggle about and hopefully create a failure

may be time for a full revival.....plugs, points, and leads

[JimStone]

Originally Posted by poppa smurf

may be time for a full revival.....plugs, points, and leads

& condenser; everyone seems to forget this one for some reason??

I would recommend checking the following,

1. Condenser mounting screw - note two potential mounting points fro condenser on the 3Y dizzy

2. Base plate earth - make sure not broken and screws are tight

3. thru body points feed - make sure nut is tight.



appologies for rough diagram, but these have been the most common faults I have come across over the last three decades for intermittent spark irrespective of manufacturer.

[poppa smurf]

brilliant stuff Jim.....very much appreciated.....I cant see most of the dizzy but this explains to me what to look for

I have found the fault and it's a wonder it didn't shut down completely before now

using your diagram I can see it is the "base plate earth".....broken but somehow it had lodged itself between the dizzy main shaft and the busted end is rubbing on the base plate thereby supplying a sufficient earth but failing intermittently

given my nonchalant attitude of "when it fails out there I can fix it".....this would have been catastrophic "out there

I cant even work out how to get to the outer screw whilst the dizzy is in the vehicle

once again......thanks to all who helped.....very much appreciated....hopefully someday I can return the favour

[302 XC]

A 3y camper , something like a hiace ???
Ive got ,well the remnants now of a hiace ute 3 Y powered here, getting to anything meant removal of the complete front seats
Some of the seats have the floor plates bolted to them,it all comes out
Thats how they pull the motors out , from inside the cabs,not sure if you knew that, but once those floor plates are out,its easy to work on

[poppa smurf]

yep! a toyota, long wheel base, full sopru conversion, camper with side awning and rear annexe......3Y 5 speed

my engine access is not too bad, the passenger and centre seat lifts up or rather pivots back revealing most of the engine

the dizzy, coil and other fun stuff are up under the drivers seat

I've just finished giving her the once over, points, rotor button, plugs, leads, condenser, air filter.....running as sweet as a nut, she goes in next thursday to get a new set of rear wheel bearings

then we are actually thinking of selling her......it will be strange indeed after all this time of ownership.....but we have the caravan and it seems silly to have both

I can see a few tears when she goes, wont take long, she's a striking looking girl, a real dark blue with large ali bullbar, driving lights and rear step....she gets looks and comments everywhere she goes