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View Full Version : TR2/3/3A Need advise of TR3 engine expert....(long)



Rustyone
03-15-2003, 01:38 PM
HELP!!!!!!! I have rebuilt my TR3 engine and it runs like crap. It idles fine(maybe a little rich) but it has no power under load, is way too rich under acceleration, backfires out of the carbs and in the exhaust. To run this car on the road I have to increase the mixture to 28 flats and then of course it is too rich but I do get enough power to run the car. All sparkplugs get light carbon suit, #1, #2, and #3 get wet while #4 usually only gets sooty--plugs get so bad that they need to be cleaned sometimes to even get the engine to start. Carb air flow is balanced. At 12 flats on a warm engine and clean plugs idle is good. After a period of idle, no acceleration, plugs are dry but somewhat sooty.

Let's start with what I know. 1962 TR3 with TR4 liners every thing else is stock. Engine compression is 150,150,150,140. The engine has been statically timed at 4 degrees B4TDC. The slot in the distributor pedestal is in the 5 minutes to 5 position when the #1 piston is at TDC. There does not appear to be any vacuum leaks. Carbs also have been re-built; new throttle shafts bt TRF and I installed gasket kits (several times). Lite oil in piston dampers such that damper pistons meet resistance at around 1/4 inch before top nuts touch threads. Pistons move freely with no interference between needles and jets upon return.

Observations of a troubling nature or observations not explained. (1) Rotor points at number 2 push rod tube when #1 piston is TDC. (2) Distributor points decidely towards head (not parallel to head as usually seen) when timed as described above. A one tooth adjustment of the distributor/speedo gear would change this orientation by 22 1/2 degrees which would be too much. (3) Furthermore, it would appear that rotor is almost beyond contact with the #1 distributor contact at point of ignition. Is this correct and this relationship is not adjustable? (4) Jet return springs (used after choking) do not return jets fully ( I should add however we have been returning them manually for the purposes of these testing). I have not tried to lubricate the jet with petroleum jelly yet. (5) The Cork gland that holds the jet assembly into the body of the carb ( before installation it is 1/4 " high with 1/8" side walls with a 3/4" or 7/8 " ID) had to be tightened very tight to keep gas from leaking and only about 1/16" of this gasket now shows from the outside.

clint
03-15-2003, 02:44 PM
If you can't get the distriutor near where it should line up, even with moving it a tooth, or that throws the timing way off, I'd double check that the timing chain is on right.

piman
03-16-2003, 09:14 AM
Hello Rustyone,
When I encounter a problem like yours I go back to square one and recheck what work I have done.
Ensure that the TDC reference you are using is actually TDC. (simple check is to put a short screwdriver into plug hole one, rotate carefully in both directions until the screwdriver just bottoms on the head, mark the damper when the screwdriver bottoms and measure from each mark back to the pointer. They should be equal, this is obviously not that accurate and care needs to be taken, but it will show if it is way out)
Take the rocker cover off and see if number four cylinder valves are just rocking at TDC, (i.e. one closing the other opening) and number one cylinder should just have fired with your 4 degrees BTDC, and the rotor arm should be aligned with your number one cylinder lead. Check also that the firing order is correct for your leads.
Does the piston on both carburettors fall onto the bridge with a click, if not the jet is not correctly centered.
When in doubt, double check and take nothing for granted,
good luck,
Alec
graemlins/cheers.gif

aeronca65t
03-16-2003, 09:31 AM
I would check what Alec has suggested first...a good start.

Then....see if the distributor advance shaft is "stuck". Put a timming light on the car and see if the spark is advancing fully (against the front pully marks) as you rev the engine. The upper shaft of the distrib could be stuck at full advance, explaining the orientation problem you've observed (rusty advance weights or broken advance springs can cause this).

Also....do you have a good strong spark?

And.....got your valves adjusted properly?

MDCanaday
03-22-2003, 02:52 PM
Rusty I am with PIman on this one, sounds like cam timing is a tooth off. To be very precise jack up the back of the car untell the block is dead level. pull the rockers off, and as PI said see when #4 push rods are dead level (put the level on the tubes and turn the crank by hand) This is DTC for the cam it should agree with the crankshaft marker.
Or it could be something too simple such as a cracked dist cap. (or carbon tracing)this can also drive you nuts. dont forget new wires for the plugs old ones can ruin your day.
You didnt mention headers but if you put some on you might have problems with the intake manifold sealing properly.
Keep us abreast of your progress!!
MD(mad dog)

tlthorne
04-01-2003, 09:13 PM
First thing came to mind was engine vacuum?
what does it say? is it steady, go down when
accelerating and rise when decelrating?

Good luck with the project

tt