Engine Problems today.

[JDNSW]

Today I took the 2a in for a pink slip, which it passed with no problems. However, soon after leaving the mechanic's it started misbehaving. Every time I slowed the engine to an idle, it would stop, and be difficult to start. It got worse every time during the day, although at first, leaving it for a while enabled it to start. Eventually, I spent about three hours trying to start it, fortunately in a shopping centre car park. During this time I pulled the carburetter to bits and found no problems, confirmed that fuel was being delivered (and the bowl was full when I pulled the carby apart), and checked the distributor without finding any problems. Eventually, after putting it back together, I got it started. By using the hand throttle to set the idle at 2,000rpm, I was able to keep it going to get home. Performance on the road was normal, maintaining 100kmh without any problems, temperature and engine sound being normal. When idling at 2000 however, the exhaust is popping and spluttering, and when I got home and moved the hand throttle back to normal, the engine promptly stopped.

Any bright ideas? I had a brainwave on the way home - sounds like a vacuum leak, possibly an intermittent one. First thing I am going to do tomorrow is pull the PCV to bits, and then vacuum check the vacuum advance. But if anyone else has ideas, lets hear them!

John

[debruiser]

maybe a bad coil????

Although remember I'm younger than your car.... so....

[vnx205]

Manifold loose?

But I suppose the exhaust manifold would be spitting too if that was the case.

Inlet manifold gasket gone allowing air to leak in, giving a very lean mixture?

If it is good under load, it doesn't sound electrical unless it is intermittent.

[jakeslouw]

Primary circuit on the carby blocked?

I assume points gap is good?

Did you swop the condensor?

What about the coil?

[JDNSW]

Manifold loose?

But I suppose the exhaust manifold would be spitting too if that was the case.

Inlet manifold gasket gone allowing air to leak in, giving a very lean mixture?

If it is good under load, it doesn't sound electrical unless it is intermittent.

Manifold is not loose and no signs of problems with the carburetter gasket.

John

[JDNSW]

Primary circuit on the carby blocked?

No, had the carby to bits, and in any case this is hardly compatible with normal operation at full throttle.

I assume points gap is good?

Not having feeler gauge with me, didn't check but it looked OK and was OK when I serviced it less than 100km earlier.

Did you swop the condensor?

Don't carry a spare, and they are not available off the shelf in Dubbo. But again, unless it is an intermittent problem, it seems unlikely, although possible, that the performance is unaffected at full throttle.

What about the coil?

Same applies to the coil as to the condenser.

John

[schuy1]

Does sound very much like a fuel related problem, blocked idle jet? An electrical fault does not really give those symptoms . They tend to be more go or completly not go across the whole rev range
Cheers Scott

[debruiser]

Actually I have heard of the coil giving these types of problems.... Not that I'm saying it HAS to be that....

If your interested. Dad bought a brand new 78 or 79 Game and from new it used to go great until it got hot, then it would stop.... couldn't start it for a while, then would start easy and go well for a while. He took it back heaps of times and they kept changing stuff (sparks, leads, distributor etc) but not the coil.... one day it stopped and the apprentice came to help him out (on the side of the road somewhere too far to walk home) and they swapped in a coil from the apprentice's car and no more problems (they tried the LR coil in the Appretice car - wouldn't start)

[JDNSW]

Does sound very much like a fuel related problem, blocked idle jet? An electrical fault does not really give those symptoms . They tend to be more go or completly not go across the whole rev range
Cheers Scott

My first thought was blocked idling jet (low speed jet to use Rover terminology), but this was why I pulled the carby to bits, and it was all OK.

I have seen cases of ignition problems mimicking fuel problems though, so these cannot be ruled out.

John

[schuy1]

My first thought was blocked idling jet (low speed jet to use Rover terminology), but this was why I pulled the carby to bits, and it was all OK.

I have seen cases of ignition problems mimicking fuel problems though, so these cannot be ruled out.

John

OK yes saw that you had pulled the carby apart After I posted;) So thats my theory done.:D Could be electrical, a broken wire flexing and intermittently connecting , although strange it went at normal revs Nothing harder than to track a fault like that down!:( Good luck!
Cheers Scott

PS What type of carby is it?

[JDNSW]

PS What type of carby is it?

Zenith

John

[JDNSW]

First thing this morning, pulled the PCV valve off. Found it very oily, more so than when I had the carbie off a week ago. Removed the top cover, and found that the diaphragm, when cleaned up, has several splits across the circular rib. Confirmed it by taping off the connection below the carbie. Engine now starts and idles normally.

Now all I have to do is see if I can get a new diaphragm.

John

[JDNSW]

Just ordered a diaphragm from Rimmer Bros - could not find one locally. I could find the entire valve, but apart from the fact that it was a lot more expensive, I'm afraid I had instilled into me in my youth, by parents who had lived through the great depression and two world wars, that you avoid waste. And replacing an entire unit when all that needs replacing is the diaphragm, constitutes waste, especially since the diaphragm is readily removed by removing a spring clip - don't even need any tools or to take it off the vehicle.

John

[JDNSW]

Just ordered a diaphragm from Rimmer Bros - could not find one locally. I could find the entire valve, but apart from the fact that it was a lot more expensive, I'm afraid I had instilled into me in my youth, by parents who had lived through the great depression and two world wars, that you avoid waste. And replacing an entire unit when all that needs replacing is the diaphragm, constitutes waste, especially since the diaphragm is readily removed by removing a spring clip - don't even need any tools or to take it off the vehicle.

I have just ordered a diaphragm from England, having been unable to find one here - complete valve, yes, but not the diaphragm. Complete valve costs $44, diaphragm $6 plus about the same paostage. Postage for the valve would be about $10

John

[JDNSW]

After I got it going last night I went for a test drive, with the intention of adjusting the idling when it warmed up - but by the time I got back it was refusing to idle again, stopped and refused to start. So today I started looking at it again. I had had the carbie apart in town, and found no problems, so I decided it must be electrical, and went over the entire ignition system with a fine tooth comb. Cleaned and gapped the plugs, dressed and set the points, tried another condenser, checked the coil, checked distributor plate earthing, checked primary circuit, checked coil lead, checked timing.

Eventually decided it had to be fuel, so pulled the carburetter to bits again (this time on a level surface, out of the sun, and with a set of steps). It seems that this problem was self inflicted. The screws holding the emulsion block were loose. I pulled it apart and checked everything anyway, and reassembled it making sure everything was tight this time. It then started and ran normally, went for a drive and when warm adjusted the idling. Now idling better than it has for some time - there are four splits in the PVC diaphragm, and it would seem that the last one to develop was the last straw.

John

[oldyella 76]

Change the coil I had the sane problem on my 2A many years ago. Like you I was convinced it was fuel. Instead it was a faulty coil.
Lindsay.

[wrinklearthur]

Hi John

Have you tried a vacuum gauge to see what the manifold is doing at idle.

Should read 0 if it stalls !!! :D:D:D
.

[JDNSW]

Hi John

Have you tried a vacuum gauge to see what the manifold is doing at idle.

Should read 0 if it stalls !!! :D:D:D
.

I don't have a vacuum gauge. The problem is now solved, operating without the PCV and with both hoses blanked off until I get the new diaphragm. I have ordered a new set of points and a condenser, although I don't think they are needed at present, but holding spares would be a good idea.

John

[wrinklearthur]

Hi John

I don't have a vacuum gauge.
Some of the early Holden Commodores had a vacuum gauge that's easily pulled out, and can be rebuilt into a glass faced box.
They have a large face that's easy to see and the air line can be a piece of windscreen washer tubing.

The problem is now solved, operating without the PCV and with both hoses blanked off until I get the new diaphragm. I have ordered a new set of points and a condenser, although I don't think they are needed at present, but holding spares would be a good idea.John
I had the exact same problems as with your Land Rover, with a series three belonging to a uncle of mine.
Did find all of those faults, but with the addition of finding a earth wire broken, the one that runs from the points plate to the distributor body.
.

[JDNSW]

Hi John

....... with the addition of finding a earth wire broken, the one that runs from the points plate to the distributor body.
.

Although I have never struck it, this is one I am well aware of, and carefully tested for it in this case.

The only primary problem I had was the PCV diaphragm, the carburetter problem was created by myself while I was looking for the problem, and I am pretty convinced that there were no ignition problems, although, having a good look at them, I think I will shout it a new set of plugs.

Also, didn't mention it, but I found a slight fuel leak in the in-line filter just before the carbie, so I have replaced this with a length of fuel hose until I get to town next.

John

[dreamin']

John

Silly question: what's a PCV? Something to do with vacuum advance?

Roger

[Dinty]

PCV is an abbreviation of Positive Crankcase Ventilation, unless I'm mistaken LOL, cheers Dennis

[muddy]

Hi John

Have you checked the vac advance/ weights in the distributor is not intermittently sticking I have had a similar problem just recently

Maurice

[JDNSW]

PCV is an abbreviation of Positive Crankcase Ventilation, unless I'm mistaken LOL, cheers Dennis

Right!

John

[JDNSW]

Hi John

Have you checked the vac advance/ weights in the distributor is not intermittently sticking I have had a similar problem just recently

Maurice

I checked that, but this would not have given the same symptoms, as far as I can see.

To summarise, the original problem was a vacuum leak due to a split PCV diaphragm. After I had located this and temporarily removed the PCV unit until I get a new diaphragm (Fred Smith has them, one on its way), the further problem turned out to be due to loose screws in the carburetter, my fault as I had pulled it to bits looking for the problem when I was in town. But looking for that I gave the whole ignition system a thorough going over.

It is now running much better than it has been for some time, probably because the diaphragm has been leaking for some time (there were actually four splits).

John

[dandlandyman]

I note you say you've checked the coil but is it the right type (ie: it doesn't say on it anywhere: USE WITH A RESISTOR. I'm not yelling, it's written in capitals) and that it's wired in the right polarity (neg or CB to distributor). I had issues with both problems years ago in my KE20 Corolla. Sounds like you've cured most of your tuning problems, though.

Dan.
69 2A 88" pet4 (still in disguise), 68 2B FC pet6 (still resting quietly for sale), plus 13 other pipe-dream-projects/parts cars (1xS2, 5xS2As, 7xS3s).