2000TC failing when hot

V

vin-kohler

Member
Advice required.
The cool engine started immidiately as usual and had its rough idle - as usual. After 20 km on a hot day (water temp. beeing ok) it started missing. I had to keep the rpm above 2000 to avoid a complete flameout. A restart was only successful after 2 hours of cooling down. The trip home via traffic lights was nasty with the rpm never below 2000 and no chance of a restart.
On today's cool morning the startup was quite innocent again.
Presuming that one cylinder is missing when hot - what is the reason?
 
COuld be more than one fault here-
Rough idle / missing whn hot could be ignition/fuel system/burnt valve or no clearance/blown gasket
Difficulty restarting when hot could be coil,condenser or fuel vaporising
Start with a tune up and compression test
 
Thank you Dave. I was afraid the verdict would be like yours.

But still, I thought a cylinder failing only when the operating temperature is comfortable and the rpm is low at the same time would be a lead.
I was thinking of a faulty valve clearance. But would that become evident under the said conditions?
I'm just wondering where to start my exploration. Compression test it is - must get a tester!

vin
 
Thank you all. Now I have a clue what to start off with. Must bring the lady to behave decently.
Enjoy the weekend!

Vin
 
I think this is definitely a Harvey question. The reason being the doubt about whether a tightening valve clearance could start to show up like this. But, of course, since you maintain your car rigorously ( :wink: ) you will already know what the valve clearances actually are.

Aside from this doubt, I would definitely be looking in the ignition system. These symptoms are reasonably normal for a failing capacitor or a failing coil. The capacitor is cheapest (presuming you are not yet electronic) so I'd change that first. Then probably the routine replacement items, rotor arm, distributor cap and plug leads (and plugs!). Then I'd see if I could beg or borrow a coil to try as a replacement to prove whether or not the coil was at fault. When buying a new one, remember to check that it is for a ballasted system.

Of course, it is just possible that you are seeing the very start of a blowing cylinder head gasket, so the compression test (hot) is a good idea anyway!

Chris
 
After 20 km on a hot day (water temp. beeing ok) it started missing. I had to keep the rpm above 2000 to avoid a complete flameout. A restart was only successful after 2 hours of cooling down
Click to expand...
That is a long warm up and cool down period. So, you would suspect something that is taking a long time to heat up and cool down. Assuming all the normal plugs, valve clearances, ignition and carb set up is right, an ignition fault as Chris suggests would be my gut feeling (apart from waiting to see what Harvey says of course :wink: )
 
chrisyork said:
But, of course, since you maintain your car rigorously ( :wink: ) you will already know what the valve clearances actually are.
Chris
Click to expand...
Well, let me wander from the subject. In the seventies I had a 2000TC and I kept it in good working condition for many years. However it was used as a workhorse, and once when the blacksmith was welding an ironplate underneath, the interior unperceived caught fire and was only brought under control when his mother splashed buckets full of water inside. With no seats to sit on left over I said goodbye to the old lady. But then, four years ago I had a vicious attack of nostalgia and bought the same model again (heaviely overpriced as I now know). My age however in the meantime has progressed well past seventy, bones and joints are not what they used to be, and a car that is friendly to me and does not complain too often is now most desirable. But I confess: I feel a trace of shame of beeing so selfish.

Back to the subject: No, I never checked the valve clearance. But all the items from the previous posts are now hot on the agenda, albeit with external assistance.

Vin
 
My "gut" feeling is the coil. Easy to check when in the failed condition: cool it down with a coolant spray or whatever you can come up with.
 
I agree, but I hate to work like that, I like to take a nice slow methodical run through the system. I have had capacitors give much the same symptoms though and the rev limiting rotor arm on the TC has a certain reputation..

Chris
 
Yes, I had one of those rev limiter rotor arms on my car. It broke down internally when hot causing the engine to cut out. So that the car wouldn't start until the engine (and rotor) cooled down. Then she started perfectly. I replaced it with one from Distributor Doctor 3 years back and it's been trouble free.

vin-kohler, if I ever make it to 70+ and I am still driving a P6, I don't think I would feel too guilty about wanting a little comfort :) .
 
vin-kohler said:
Advice required.
The cool engine started immidiately as usual and had its rough idle - as usual. After 20 km on a hot day (water temp. beeing ok) it started missing. I had to keep the rpm above 2000 to avoid a complete flameout. A restart was only successful after 2 hours of cooling down. The trip home via traffic lights was nasty with the rpm never below 2000 and no chance of a restart.
On today's cool morning the startup was quite innocent again.
Presuming that one cylinder is missing when hot - what is the reason?
Click to expand...

Just some quick thoughts in addition or alongside what has been written already. Coils and condensers are prone to failing when hot, but if you can prove that it is one particular cylinder that always causes the problem, then it won't be either of those causing it. They will cause random running of all cylinders. You need to find out if it is one particular cylinder, if so which one, and then interchange parts until the misfire moves. If it's randomly affecting all cylinders, then they are a good place to start though.
All that assumes everything is in good condition to start with, if not, get it so it is, by which time the fault may have disappeared, if not carry ot the above. Running a compression check is always a good idea, it gives an idea what you're working with, and could show up the fault. You could do one check cold, and then another when it's hot, and has the problem.
If it is a TC with a rev-limiting rotor arm, replace it with a normal one.
 
Thank you, Gentlemen, for your useful suggestions. I have now a good strategy to attend to the matter. That will be on tuesday.

Vin
 
harveyp6 said:
All that assumes everything is in good condition to start with, if not, get it so it is, by which time the fault may have disappeared, if not carry ot the above. Running a compression check is always a good idea, it gives an idea what you're working with, and could show up the fault.
Click to expand...
After considering my abilities and the means I have, I decided to chicken out and to hand the car over into able hands.

A short description of yesterday's tranfer might be in order: Having started in the early morning I had an uninterrupted and uneventful ride of 250 km at 130 km/h +/-. But then traffic congestions began, and as soon as I couldn't keep the revs high enough the engine failed and refused a restart for the next 40 mins. That went on. When finally I was blocking a traffic light I asked for a tow to cover the remaining 6 km.

Thanks to your knowledgeable suggestions I had an informed talk with the expert. Once the car is back on the road again I will certainly report.

Vin
 
harveyp6 said:
If it is a TC with a rev-limiting rotor arm, replace it with a normal one.
Click to expand...

For the sake of future-proofing that component, go for one of the resin red rotor arms from Powerspark (simonbbc). One of the instalments in the epic dramatic trilogy that was my ignition saga a few years back was traced to a rotor shorting to the cam through the rivet because the plastic had gone brittle. The red ones don't dry or crack and don't have a rivet.

Just a small thing, but if you're buying a new one anyway......

Michael
 
redrover said:
harveyp6 said:
If it is a TC with a rev-limiting rotor arm, replace it with a normal one.
Click to expand...

For the sake of future-proofing that component, go for one of the resin red rotor arms from Powerspark (simonbbc). One of the instalments in the epic dramatic trilogy that was my ignition saga a few years back was traced to a rotor shorting to the cam through the rivet because the plastic had gone brittle. The red ones don't dry or crack and don't have a rivet.

Just a small thing, but if you're buying a new one anyway......

Michael
Click to expand...
The rotor arm I got from Distributor Dr was a red one. IIRC, I did a bit of reading when mine failed and apparently many of the modern rotor arms made of black plastic should perhaps be avoided. This is because they use too much carbon to colour the plastic black during manufacture. Obviously carbon is a conductor, so this is not a good idea when you are relying on the plastic to act as an insulator! For this reason, I tend to be a little suspicious of rotor arms and distributor caps made of black plastic.
 
I've got the idea, and red it will be.
Still it is peculiar that so many millions of these failure prone arms have been installed. Are they intentionally build to fail? Should like to hear the opinion of a rotor arm design engineer.

Vin
 
Harvey, looking again through past posts this line struck me.
harveyp6 said:
If it is a TC with a rev-limiting rotor arm, replace it with a normal one.
Click to expand...
How does that thing operate? And how can I distinguish this one from a normal one by looking at it?

Vin

Oh, I found the answer. It's got a centrifugal cut off. Easy to recognise. Thanks anyway.
 
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