MautoK
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| posted on 7/6/09 at 11:46 AM |
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Another Ignition Module Q
Gents,
As you're probably tired of hearing, I've been having overheating problems. 
I'm currently running standard 2L Pinto with original carb, distributor and ESC II and I'm wondering whether the ESC II is playing up. The
car actually drives fine, it just overheats after a few miles.
The distributor looks like a Hall-effect unit, has a solid shaft and no vacuum unit. Therefore I'm inferring that all advance requirements are
taken care of by the ESC II. Could it be misbehaving? Well, of course, it could be....
I have twin SUs + manifold that I was aiming to fit once I had sorted the overheating, but now considering fitting them along with a different
ignition module. The ESC II does a load of messing with the carb - there's a stepper motor to control idle - that will be redundant with the
SUs. So I would like to fit an ignition system that just does ignition.
Options are:
1. Leave the ESC II and live with it;
2. Go back to a basic system - find a distributor with internal mechanical advance and vacuum unit (like the old Lucas A-series type); even a points
unit so no ign. module at all...?
3. Megajolt
Comments please! 
Thanks,
John.
He's whittling on a piece of wood. I got a feeling that when he stops whittling, something's gonna happen. (OUATITW/Cheyenne)
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omega0684
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| posted on 7/6/09 at 11:49 AM |
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megajolt
john have you changed the pressure cap of the header tank?
[Edited on 7/6/09 by omega0684]
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MautoK
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| posted on 7/6/09 at 12:05 PM |
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Alex,
One vote for MJ...
Standard cap. It holds pressure well - when it gets boily and I unscrew the cap there's a great eruption as the pressure releases...
John.
He's whittling on a piece of wood. I got a feeling that when he stops whittling, something's gonna happen. (OUATITW/Cheyenne)
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omega0684
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| posted on 7/6/09 at 12:15 PM |
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pressure caps can appear to work when they actually don't, the spring could be worn etc, the cap might be allowing the water to boil and and
releasing all your water?
might be worth replacng it for the sake of a couple of quid?
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02GF74
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| posted on 7/6/09 at 01:36 PM |
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quote:
Originally posted by MautoK
I've been having overheating problems.
I'm wondering whether the ESC II is playing up.
The distributor looks like a Hall-effect unit, has a solid shaft and no vacuum unit. Therefore I'm inferring that all advance requirements are
taken care of by the ESC II. Could it be misbehaving? Well, of course, it could be....
Assuming you don't live in Saudi, then overheating can be caused by engine or cooling system.
engine would be ignition or fueling - we can rule out lack of oil or friction.
let's look at one thjing at a time, and we start with the easier - ignition.
From you description, there is no advance in the dizzy but done via ecu.
Attach a timing lamp and look how the timing changes at different RPM. This will sjow advance is working or not. The next step is to determin TDC of
engine - the timing marks can be out - so you can see the actual value of the timing.
This will more or less rule out ignition.
Doe the ecu use engine vacuum?
Next you need to look at the carb although an exmaination of the spark plugs after a hard run will probably tell you all you need to know.
The last step is the colling system.
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MautoK
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| posted on 7/6/09 at 03:58 PM |
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I've rigged up the strobe, but can't see squat with it at the moment - even dobbing some paint on the pulley.
So...I refitted the distributor, deliberately over-advanced. It didn't start, stalling the starter motor. Gradually retarded it until the engine
did start and ran cleanly.
Left it idling and the temp came up - a bit more slowly than previously I think, but I wasn't watching that closely. Gauge came up to mid scale
and seemed to settle. Could feel the warm front advancing across the rad as expected.
But after about 10-12 minutes the gauge continued relentlessly upwards and by about 15-17 the header cap was wheezing, expelling air/gas and water,
and bubbles were coming up the 8mm pipe from rad bleed + 'stat bleed ports which are now tee'd together.
The ESC II has have a vac pipe from the carb, but as I can't see the strobe I can't tell whether it is varying the timing dependent on
revs or vac. Will try in the dark... (The strobe is working per se, but there's too much ambient light.)
I'm still having 'orrible thoughts of cracked block or head.
He's whittling on a piece of wood. I got a feeling that when he stops whittling, something's gonna happen. (OUATITW/Cheyenne)
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02GF74
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| posted on 7/6/09 at 06:09 PM |
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in that sequence of events, at what point did teh fan trun on and then stop? (assuming you have electric fan fitted).
yeah - try the tming lamp when it is darker.
if the block was cracked, would water not be lost via the exhaust?
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MautoK
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| posted on 7/6/09 at 10:04 PM |
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After it started boiling I switched the ignition off; the fan had not come on. About a minute later ign on (without starting engine) and the fan was
running.
I went out about 10pm and fired up the engine in the garage. Strobe was all over the place
I need to get a good solid blob of paint on there and try tomorrow....and get sight lines better established - the headlight bar gets in the way.
John.
quote:
Originally posted by 02GF74
in that sequence of events, at what point did teh fan trun on and then stop? (assuming you have electric fan fitted).
yeah - try the tming lamp when it is darker.
if the block was cracked, would water not be lost via the exhaust?
He's whittling on a piece of wood. I got a feeling that when he stops whittling, something's gonna happen. (OUATITW/Cheyenne)
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02GF74
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| posted on 8/6/09 at 07:06 AM |
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quote:
Originally posted by MautoK
After it started boiling I switched the ignition off; the fan had not come on.
Does this not sound unusual to you?
Unless you live on top of a very high mountain, pure water boils at 100 degrees C.
Assuming you have not added additives to reduce the BP, then surely the fan should come on at around 90 - 95 degrees????
Too late it coming on when water is boiling which if your pressure cap is on and working properly, would be around 105 degrees or so?
How is the fan wired up?
Where in the plumbing is the temp switch fitted for the fan?
At what temp *should* the switch close to switch on the fan?
[Edited on 8/6/09 by 02GF74]
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MautoK
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| posted on 8/6/09 at 10:21 AM |
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Hmmmm, yes!
We're at the dizzy height of 500 feet above sea level; the cooling system is filled with the finest Devon tap water.
The thermoswitch for the fan is in the rad hot end; there's a manual override switch in parallel and a relay switches the heavy current to the
fan itself. I also have a telltale light in parallel with the fan (can't always hear the fan operating)
The thermoswitch is from a 1983 Talbot Samba in which it was almost identically mounted (rad hot tank). Not sure what its on/off rating is but it
seems to work properly.
The fan coming on after the engine is switched off suggests that that there's a super-hot slug of water thermo-syphoning around. If I'd
left the engine running a little longer the fan would have switched on (as it has on previous tests)
I still have to do a hot compression test, but I'm convincing myself that I do have a cracked block/head - a crack that is benign at ambient but
opens up at operating temp.
May not be able to do much today due to domestical commitments and the monthly shopping grind , but will try to stoke it up and do the hot comp
test.
Cheers,
John.
quote:
Originally posted by 02GF74
quote:
Originally posted by MautoK
After it started boiling I switched the ignition off; the fan had not come on.
Does this not sound unusual to you?
Unless you live on top of a very high mountain, pure water boils at 100 degrees C.
Assuming you have not added additives to reduce the BP, then surely the fan should come on at around 90 - 95 degrees????
Too late it coming on when water is boiling which if your pressure cap is on and working properly, would be around 105 degrees or so?
How is the fan wired up?
Where in the plumbing is the temp switch fitted for the fan?
At what temp *should* the switch close to switch on the fan?
[Edited on 8/6/09 by 02GF74]
He's whittling on a piece of wood. I got a feeling that when he stops whittling, something's gonna happen. (OUATITW/Cheyenne)
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DarrenW
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| posted on 8/6/09 at 12:22 PM |
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Cooling system - i assume you are using antifreeze with Devons finest? Any air leaks? (can be tricky to get them out). Is the block nice and clean? I
ask as one of my blocks was very crudded up, i removed a water gallery plug when i was flushing it out and no water came through. Took a while with
wire and screwdrivers to get in cleared and running - this had the effect of restricting water flow through the block and was easily recitified.
Dizzy - i assume yours has a plug mounted on the carb body rather than on a flying lead? This is normally the way to identify if it is the hall effect
one or not. Normally people dont fit the hall effect type due to wiring difficulties, but that is more to do with upgrading from points to electronic.
Im not sure how to determine i fthe hall effect set up is running correctly, but id guess you should be able to do some checks with a timing light.
Assuming ignition is OK its worth double checking the cooling system is plumbed OK and circulating before going any further.
Sounds strange that the fan didnt come on. Could be worth checking fan wiring and switch.
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