Engine running roughly

G

georgecook

Member
Am trying to do what I believe are the correct "things" to try and resolve my 2000TC engine problems. Have moved the distributor( electronic) around, changed plugs and checked the compression. The compression varies between 125psi and 160., which I believe is probably acceptable.. The oil pressure after running the engine for around 5 minutes, remains at 50 psi. After re checking the plug gap on the new plugs it was obvious that the plugs from cylinders 3 and 4 were very sooty. Does this indicate that the carb supplying cylinders 3 and 4 is running rich. Could this be the answer or are there a thousand other things which I should check before starting to play around with the carburettor?....georgecook
 
georgecook said:
my 2000TC engine problems.
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georgecook said:
Have moved the distributor( electronic) around,
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Just randomly moved it, or set the ignition timing?

georgecook said:
checked the compression. The compression varies between 125psi and 160., which I believe is probably acceptable..
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I'd say that was a bit too much of a spread. Ideally you'd be looking at maximum of 10% variation between cylinders.
Have you checked the valve clearances?

georgecook said:
The oil pressure after running the engine for around 5 minutes, remains at 50 psi.
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The oil pressure will have no effect on how it runs, unless there wasn't enough pressure to operate the timing chain tensioners, and if that were the case, you'd hear the chain.

georgecook said:
After re checking the plug gap on the new plugs it was obvious that the plugs from cylinders 3 and 4 were very sooty. Does this indicate that the carb supplying cylinders 3 and 4 is running rich.
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Yes.



georgecook said:
are there a thousand other things which I should check before starting to play around with the carburettor?....georgecook
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Not quite thousands, but plenty enough. You need to eliminate all problems in the ignition system, set the ignition timing, and then you can move on to the carbs.
 
The compression varies between 125psi and 160., which I believe is probably acceptable..
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Err, no. +- 10% ideally nearer 5% 125psi is way too low for a 9:1 CR engine. Repeat the test with some oil (the wet test) that'll tell you if its valves or rings.
 
Thanks fellas ....As I have the plugs out, I will carry out a wet compression test. How much oil do I need for each cylinder and can someone remind me which way the results indicate ,is it higher for rings or valves? Alternatively do I replace the plugs first, and set the ignition timing.
Have tried to check valve clearances but am unable to turn the engine ( with plugs out) the fan belt just slips around the crankshaft pulley. I realise, a large socket on the crank pulley would be the answer, but don't have one, any suggestions please....georgecook
 
georgecook said:
.As I have the plugs out, I will carry out a wet compression test. How much oil do I need for each cylinder
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Just a few squirts from an oil can.


georgecook said:
and can someone remind me which way the results indicate ,is it higher for rings or valves?
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If the readings go up it's the rings, if they stay pretty much the same it's a valve problem.

georgecook said:
Alternatively do I replace the plugs first, and set the ignition timing.
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Do your compression check first.


georgecook said:
Have tried to check valve clearances but am unable to turn the engine ( with plugs out) the fan belt just slips around the crankshaft pulley. I realise, a large socket on the crank pulley would be the answer, but don't have one, any suggestions please....
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Put the car in top gear and roll it backwards and forwards. Don't forget to do it with the engine stone cold, and don't forget to take it out of gear afterwards.
 
Will recheck my compression figures later this morning, first of all dry again, followed by the wet method and keep you posted.
I did however manage to check my valve clearances, these are front ( radiator ) to back Metric... mm
0.04
0.3
0.12
0.12
0.12
0.07
0.08
0.04
These figures are in the main very tight according to the manual. Would worn tappets or valve seats cause this ?....georgecook
 
Apologies
0.0016ins
0.019
0.005
0.005
0.005
0.003
0.003
0.0016
Other than the exhaust on number one cylinder the clearances are well down......georgecook
 
If the clearances are that tight, it will affect how the engine runs, and they need to be set correctly before you move on to anything else.
 
Thanks harveyp6 ..would it be of benefit to carry out the wet and dry compression tests now. This would determine whether or not I need to remove the cylinder head anyway...georgecook
 
The problem you've got is that those tight valve clearances will affect the readings you get when doing the compression test, and so as you did get readings previously, I'd do a wet test, and my guess is that you won't see much improvement, meaning that setting the valve clearances should improve the compression readings and the running issues.
 
georgecook said:
Will remove the camshaft and try to sort out those shims .. many thanks.....
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I have a reasonable selection of used shims that I can sell you on an exchange basis once you've sorted out your size requirements if you have the need.
 
Thanks harveyp6... have removed the camshaft and bought a micrometer (metric) at Toolstation, am now in the process of measuring the shims. Starting to become concerned as I am now realising how far out my valve clearances have been. For example, unless I have made mistakes(highly likely) moving from metric to imperial and back again the first shim I have measured would need to be 2.246mm less in thickness .Could an engine run with typical valve clearances such as these? Would certainly like to take you up on your offer re the shims ...need to get my measurements sorted. georgecook
 
Measuring in Metric, then converting to Imperial shim sizes is a recipe for disaster. You should have bought an Imperial micrometer....
 
2.246mm is a huge number for these! that's 0.88", clearances for our cars are in the region of 0.009"-0.011" for inlets and 0.013"-0.015" for exhausts I believe! I would double check your maths if I were you.
 
harveyp6 said:
sdibbers said:
clearances for our cars are in the region of 0.009"-0.011" for inlets
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0.008"-0.010"
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So close! I used to be able to remember these things without losing a digit or two. But, yes, 0.088" is way off and sounds wrong on the maths side of things.
 
sdibbers said:
But, yes, 0.088" is way off and sounds wrong on the maths side of things.
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The perils of using Metric micrometers to reset clearances to Imperial measurements using Imperial shims.
 
I Know, I know, I know I made a minor error regarding my calculations... well a major one really. I am a Sunderland supporter and we are not supposed to be very bright anyway.
I just cannot understand why the whole world will not change, just to suit me and my metric micrometer...0.2286mm Inlet .and 0.3556mm.Exhaust....georgecook
 
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