Hi All,
 
I have just picked up a mk1 with a pinto conversion and it seems to have a relatively consistent slight ping to it that is there when its cold or warm.
 
At idle its there a little bit, when i accelerate it might come and go, when im cruising around 3000 RPM at a constant speed though (like on a main road holding a constant speed) it disappears and then might come back ever so slightly.
 
Things i know about the car that i think may be contributing:
- there is a vacuum leak i suspect somewhere because when i stick my foot on the brake at the lights the rev's raise
- it has a brand new 32/36 carbie on it and im not sure what any of the jetting is
- i have checked the timing and all timing marks are lined up correctly (cam, dizzy, crank) and at idol (with the vacuum advance still connected) its sitting around 8' TDC.
- the temp seems to continue to slowly climb up over a period of about 30 mins where it gets to the point that it is almost at the red and i shut it down.
 
Suppose my questions are:
1) Does it sound like its being caused by running lean, potentially from the vacuum leak, potentially because of the unknown jetting.
2) Would the right approach be to block the booster vacuum connection on the manifold (booster / dodgy line is where i suspect the leak is), fire it up, confirm the timing is correct again and test to see if the ping is there (can replicate the ping by just holding revs slightly off idol)
3) What are the chances its an issue potentially with the vacuum advance on the distributor, is it worth blocking that too and setting the timing again and testing? Is that the best way to set the timing.
 
Any experience that can be shared with this kind of issue would be greatly apprecaited.
 
Thanks,
 
Josh
 
 
 
 
 
 
 
 

Gday Josh
Had the same overheating problem on my mk2.
Have you tried a colder thermostat ( tridon tt4-180 ) it fixed my overheating.
Mark

Thanks Mark,
Hopefully this weekend i can get a couple of hours to have a look. For the sake of $20 i might just replace it anyway so its one less thing to worry about. Thanks again!
Josh

Bit of an update:
 
Blocked the brake booster off at the manifold. Issue is still there.
 
I checked the Thermostat and its working okay, opens up fine and i can see the water pumping through once the car is warm
 
I checked the spark plugs and they appear to be a coffee colour so i don't think its running lean.
 
Also checked the jets and they seem to be in line with what people are running on a standard pinto for a 32/36.
Main's
140/140
Air Correction
145/160
Idol
60/50
Idol Screw
2.5 turns.
 
 

Whooligan has probably nailed it. 
I have been continually warned by people employed in the petroleum industry that the quality of petrol is now very poor. Apparently Australia is a dumping ground for poor quality imported fuel.
This time last year I had fuel related problems from using 91 octane fuel in a car I have owned since 2001.
I now only use good quality 98 octane.
Very questionable however impossible to prove if 91 octane is actually 91, and 98 octane is actually 98.
Unfortunately we live in a commercial world where the profits of powerful multinational companies take precedence.
 
 

Thanks for the ideas...i wasn't sure what fuel was in it (it was in there since i bought ti) so I drained the tank and got some fresh 98 but its still there.
 
While i was under the car though i did notice that the exhaust about half way down the car has been squashed up against the under side of the body at some stage and its compressed the pipe to about 1/3 of its size.
 
im now starting to wonder if its chocking on its own exhaust a little bit (or a lot!)
 

Josh, is your compression ratio too high fir the fuel and perhaps try colder plugs. I had similar issue and part of it was that the machining done on the head created sharp edges which developed heat concentrations. Something to consider
Rodney

Just thought i would close the loop on this one.
 
Couple of things, the overheating was because there was no thermostat in there at all. I stuck in a tridon tt4-180 as recommended by @mvscon and its been working the treat. Turns out wasn't running lean etc.
 
Also the ping noise. Managed to get it up in the air and get under the car and it sounded like the noise was coming from down low (inside the bellhousing).
 
Whatever mechanism that pulls the starter gear back in was shagged and at a particular revs the harmonics must have just been enough for the starter motor pinion to work its way out and it was clipping the flywheel (the ping noise) and then pushing back.

Engine ping is usually constant, usually happens during acceleration and is telling you that the ignition timing for the compression ratio and fuel octane and engine speed is incorrect. Is easy to determine on a dyno and usually can be eliminated, but not always as the fuel octane rating may not be available or financially viable even for a track car.
It is the onset of pre-ignition or over advanced ignition in most cases and is not to be confused with actual mechanical noise from any source which have to be eliminated first.
 
 

Im ressurrecting this old thread, just to ask what octane fuel you guys normally use?
I am planning to drain the old fuel in my 1600 crossflow, now that its back on the road.
 
Currently it is pinging a bit when under load, but given that its sat idle for a few years, it's not too surprising and I expect the valves are probably sticking a bit.
It has a 1600 GT mild cam, 32/36 weber, but the HC head remained fairly std from memory. I need to use lube additive, as it did not have hardened seats done back then.
 
So with fresh fuel, like 98, what basic timing should I be looking for?
Then take it somewhere for a decent tune?