Outer Limits 4x4 Board

I drove my car for 18 hours/1700km on the weekend before last, only stopping for fuel. It's a carburetted TB42 ie a 4.2 litre straight six.

Temperature was rock steady, oil pressure good, no smoke, all looked good on the gauges.

But after the first 200km or so, it started to run a little poorly, basically not wanting to rev, slowly getting worse, and by the time I arrived at my destination, it was a real struggle to get it to rev over 2800 rpm or so without juddering and basically feeling shit.

My gut told me it was having trouble making good spark. The next day, after some pretty heavy sleeping, I pulled the dizzy cap and rotor off and checked the points. They looked kinda worn to me (I was expecting a lump of molten slag), as though they weren't opening enough. I didn't measure anything, I just casually bent them out a microscopic bit and now it runs fine.

But I don't know if that is because I bent the points open slightly, or because I haven't run it for such a long period again.

I'm guessing that the points or the coil got extra hot on the long trip since they don't get much help from the cooling system. I also noticed it improved slightly when I stopped for 20 minutes or so, and when I hit cold rain just north of Melbourne.

What do you reckon? Was it just the points? Or coil? Or something else? Something not even electrical? It runs now as if there had never been a problem at all, but I'd like to replace the shagged component.

Jason

Sounds more fuel related to me.

Is it possible the fuel was vaporising????.......this will happen when the fuel lines are to close to areas of the motor that allo0w it to get to hot.

Are the fuel filters clean???

Dirty filters will cause the car to struggle under load.

Have u checked the timing????..........Is the motor pinging at all????

Always use a feeler guage to do points and plugs..........most important.

Points should not burn out unless u leave the ignition on with out the motor running.

Have u checked the radiator for signs of oil???...usually evident by small bubbles of oil sitting on top of the water under the cap.

Or alternately the motor for water???........easy to test.......just remove the oil filler cap........turn it upside down and look at what u see.........it should be just a smear of pure oil.........any white sludge looking stuff may indicvate water.

Both of the above indicate a stuffed head gasket and that can cause the motor to only rev to a certain point.........usually (but not always).......this will cause the vehicle to overheat.

Are you certain the temp guage is working?????

For some silly reason I thought you'd have one of those Jaycar electronic ignition kits. If you haven't got one, just do it - they work real well, and eliminate some points type problems.

I had a problem on my Galant, because that little block which rubs on the lobes inside the distributor was worn away. This meant that the points were barely opening, and because they were opening later, it had retarded the ignition too. Without the electronic kit my dwell would have been stuffed, and I probably would have had all sorts of problems with poor ignition, like arcing across the points? With the Jaycar kit the electronics took care of the dwell, and less points current meant arcing wasn't an issue. The only problem I noticed was loss of power as the ignition slowly retarded itself. I advanced it several times before I worked out what was happening.

Could this be part of your problem?

Cheers,

Scott

It will be those points - The jaycar kit is the go - I know the feeling of the car I have had it with my old rangie. My problem was that the ignition system needed ballast block and didn't have. The points copped a flogging and would die at regular intervals with marks on it like someone was stick welding on them

My car had a jaycar kit on it at some stage but it was removed when it died (after about 10 years or so of use) and at the time I knew nothing about points and ignitions so I just put a fresh set of points in and away we went. After several sets of points I realized what was going on.

Popped in a ballast and she was sweet as.

Check you leads as well - look for marks where they have been earthing out, check your cap for lines etc. What can happen is the plugs can get harder to fire then points go and as you stress them further by driving it and then it will eventually cause a lead to earth out and then the cap will start earthing out.

The PITA is replacing the bits in a logical and economical fashion, you don;t want to put a new set of points in only to have them poo their pants cause other things are busted. Check it out

Tom

What you guys are saying is all true.....however in this guys case i dont think it applies as he is claiming that it was all ok when the vehicle had cooled down.

A points prob wont change just cos the engine is cool..........well not to my knowledge.

Oh and great call with the electronic ignition to.

Top Cat wrote:
A points prob wont change just cos the engine is cool..........well not to my knowledge.

Like Top Cat said I don't think it will go away when the car is cooler, I was thinking perhaps it cooled down everything so there was less stress on the plugs to fire ? Talking out of my a$$ here

Tom

RaginRover wrote:

Top Cat wrote:
A points prob wont change just cos the engine is cool..........well not to my knowledge.

Like Top Cat said I don't think it will go away when the car is cooler, I was thinking perhaps it cooled down everything so there was less stress on the plugs to fire ? Talking out of my a$$ here

Tom

Yeah that's kinda what I was thinking of too, in particular the coil.

I'm not sure I even need to worry about it for a while as I'm not really planning any long trips in the near future.

Jason

Tom's mention of a ballast resistor reminded me - when I was a youngster I bought a new coil for my car. It took me a couple of years to realise I bought a coil designed for a ballast resistor, and was running it without one. Because it was designed to run with about 7 volts, and I had around 14V across it, it got very hot - I discovered this when I burnt myself with it.

I was having other ignition problems anyway, so I don't know what sort of problems it might create (if any) - but it could be worth looking into?

On the subject of leads & Kettering ignition systems. I can imagine dodgy leads would lose their ability to transfer spark as they get hotter. A standard points system has less energy available per spark as the revs rise. Put the two together and that might explain Dr Chimp's symptoms.

Cheers,

Scott

NJ SWB wrote:
Because it was designed to run with about 7 volts, and I had around 14V across it, it got very hot - I discovered this when I burnt myself with it.

The other thing that made me think of is - not to leave your car on full ignition when it is not running, i.e make sure it just sits on accessory
when you have a points ignition, if the points are closed it will sit there and make the coil cook itself - learned that the hard way.

With you 14V across you points it would shred them out in a shorter period of time - like 5000K before adjustment perhaps less. I read somewhere or someone told me that points are usually only good for 10,000K and should be replaced. $26.00 item in my rangie and I know the part number by heart

Probably would have used half the number of points if I learned/read/knew about it from the beginning !

Tom

When I bought my VL commodore from a dealer it would run fine when it was cold but as soon as it hit operating temp it would cough and fart. I took it back under warranty and they gave me an injector cleaner and replaced the fuel filter etc. It took three times of me going back to get the shits and take it to an auto electrician. The leads were worn out and arcing, my money is on the leads as I've had the exact same problem.

high n mighty wrote:When I bought my VL commodore from a dealer it would run fine when it was cold but as soon as it hit operating temp it would cough and fart. I took it back under warranty and they gave me an injector cleaner and replaced the fuel filter etc. It took three times of me going back to get the shits and take it to an auto electrician. The leads were worn out and arcing, my money is on the leads as I've had the exact same problem.

for a vl this sounds more likely to be a crank angle sensor starting to play up

one of the most common faults in that model... ah ive had 4 of them

Ice wrote:

high n mighty wrote:When I bought my VL commodore from a dealer it would run fine when it was cold but as soon as it hit operating temp it would cough and fart. I took it back under warranty and they gave me an injector cleaner and replaced the fuel filter etc. It took three times of me going back to get the shits and take it to an auto electrician. The leads were worn out and arcing, my money is on the leads as I've had the exact same problem.

for a vl this sounds more likely to be a crank angle sensor starting to play up

one of the most common faults in that model... ah ive had 4 of them

CRANK ANGLE SENSOR IS ON ITS WAY OUT !!!!!!!!!!
get it looked at or else it'll go bout 3-4 kays and then just cut out and die til it cools down again !

Sounds more fuel related to me.
CHIMPBOY !!!!!!

ur tank isnt pressurising is it !! fuel tank breather may have crap in it that makes it run like a second hand mower sometimes !


just a thought

thats acutally anther vl problem lol

the fuel breather lines perish badly... you have to take the tank out to replace them though

not a bad car except for a few little things like that

RaginRover wrote:

Top Cat wrote:
A points prob wont change just cos the engine is cool..........well not to my knowledge.

Like Top Cat said I don't think it will go away when the car is cooler, I was thinking perhaps it cooled down everything so there was less stress on the plugs to fire ? Talking out of my a$$ here

Tom

if the points are two close it will over heat the coil after a while there for dropping spark and some times causeing back fire through the carby DONT STUFF AROUND get a electronic setup (been there done that) better starting better power and no more points to clean