Cant get my 2500M to start
Discussion
Hi,
I have a 2500M, which has been through a period of ill health, which has resulted in an engine out, strip and rebuild, at the hands of yours truely. Whilst at it I had the head skimmed, new valves, guides and an unleaded conversion. Anyhow, now its all back together and back in the car but I cant get it running, I think I might be going mad, so be grateful if anyone can suggest anything stupid I might have done.
I have set the timing marks on the crank shaft and cam shaft, made sure I'm at 11° BTDC (as per TR6 book) on the compression stroke for No 1 cylinder, set the distributor so that its pointing at the correct lead, with the electronic ignition just entering the firing zone. Its running twin SU's (HS8s) which were taken off with the inlet manifold and otherwise have been untouched, it has an electric fuel pump with a pressure gauge immediately before the Carbs & there is fuel in the float chambers... There seems to be a spark at the plug, I'm not sure how to check fuel actualy makes it into the engine from the carb, but I cant see why it wouldn't...
Looking through the TR6 manual the only thing it seems to easily get wrong would be to set the timing sproket on the cam shaft 180° out, but as all the timing is set of the cam shaft, and the crank shaft goes around twice for each rotation of the cam shaft, I cant see that this would actually make any difference (I havent checked this again but I'm 99% that I got it right the first time anyhow)?
Anyone got any ideas?
Cheers
Warwick
I have a 2500M, which has been through a period of ill health, which has resulted in an engine out, strip and rebuild, at the hands of yours truely. Whilst at it I had the head skimmed, new valves, guides and an unleaded conversion. Anyhow, now its all back together and back in the car but I cant get it running, I think I might be going mad, so be grateful if anyone can suggest anything stupid I might have done.
I have set the timing marks on the crank shaft and cam shaft, made sure I'm at 11° BTDC (as per TR6 book) on the compression stroke for No 1 cylinder, set the distributor so that its pointing at the correct lead, with the electronic ignition just entering the firing zone. Its running twin SU's (HS8s) which were taken off with the inlet manifold and otherwise have been untouched, it has an electric fuel pump with a pressure gauge immediately before the Carbs & there is fuel in the float chambers... There seems to be a spark at the plug, I'm not sure how to check fuel actualy makes it into the engine from the carb, but I cant see why it wouldn't...
Looking through the TR6 manual the only thing it seems to easily get wrong would be to set the timing sproket on the cam shaft 180° out, but as all the timing is set of the cam shaft, and the crank shaft goes around twice for each rotation of the cam shaft, I cant see that this would actually make any difference (I havent checked this again but I'm 99% that I got it right the first time anyhow)?
Anyone got any ideas?
Cheers
Warwick
Are the plugs wet with fuel?
Does it stink of fuel?
If not try getting someone to squirt some easy start into the air intake while turning it over - if it fires you have a fuel problem. (You could I guess just squirt a bit of fuel in)
If the plugs are wet you need to dry them thoroughly with a blowlamp or similar, not just a wipe with a cloth.
Does it stink of fuel?
If not try getting someone to squirt some easy start into the air intake while turning it over - if it fires you have a fuel problem. (You could I guess just squirt a bit of fuel in)
If the plugs are wet you need to dry them thoroughly with a blowlamp or similar, not just a wipe with a cloth.
I'm no expert but if it were me I'd check fuel is getting into the cylinder OK (as per last post) then try testing the leads & spark plugs for a spark. Using insulated handled pliers or wearing rubber gloves, hold the plug (HT lead attached) so that the tip is 1mm from the cylinder head. With someone using the ignition to crank the engine over, you should see the spark. Alternativly remove lead from spark plug & hold the end of the lead about 1mm from the cylinder head (this won't test the plug). If you are then sure you have fuel & a spark, I would check the compressions are OK, otherwise as you've said it must be the timing.
Moto
Moto
3 basics as covered.
Spark
Air
Fuel.
Spark you'll see. Check all plugs are healthy
Air you'll feel if you put your hands over the carbs sucking into engine.
Fuel you'll smell and have wet plugs as advised.
Again as moto otherwise timing.
And also as before compression.
Tbh when i rebuild mine I, for the first few times poured a small amount of fuel straight into my carb.
Stick at it :-)
Spark
Air
Fuel.
Spark you'll see. Check all plugs are healthy
Air you'll feel if you put your hands over the carbs sucking into engine.
Fuel you'll smell and have wet plugs as advised.
Again as moto otherwise timing.
And also as before compression.
Tbh when i rebuild mine I, for the first few times poured a small amount of fuel straight into my carb.
Stick at it :-)
Is the petrol fresh? If it's old then that could be the problem. Is the battery fully charged - is cranking quickly enough? Do you have a ignition timing light? That would help you see if it's firing - and when it's firing.
Unfortunately it is really easy to get the timing 180° out, also, getting that dizzy drive gear installed correctly is a pain (took me LOTS of attempts on a spit I once had).
Keep at it and you'll get there!
Unfortunately it is really easy to get the timing 180° out, also, getting that dizzy drive gear installed correctly is a pain (took me LOTS of attempts on a spit I once had).
Keep at it and you'll get there!
ON the same theme....
check you are getting sparks first, it's the easiest thing to check... power to ign coil and earth strap to engine ? Does your ignition have a bypass and resistor ? (later 2500 systems had this for easier start) make sure that's OK. If sparks then ...
After turning over a bit the exhaust should smell of petrol. Then you know at least it's making it's way through the system.
It's all too easy to put the dizzy in 180 degrees out, check this, and then check it again just in case. I had this very problem on a T2500 saloon, and after a frustrating hour realised I had indeed put the dizzy in the wrong way round.....Doh!!
Firing stroke on cyl 1 has NO VALVES MOVING during it's firing compression (up) and stroke (down) as a double check.
could be flooded, take plugs out and make sure they ain't wet....
check you are getting sparks first, it's the easiest thing to check... power to ign coil and earth strap to engine ? Does your ignition have a bypass and resistor ? (later 2500 systems had this for easier start) make sure that's OK. If sparks then ...
After turning over a bit the exhaust should smell of petrol. Then you know at least it's making it's way through the system.
It's all too easy to put the dizzy in 180 degrees out, check this, and then check it again just in case. I had this very problem on a T2500 saloon, and after a frustrating hour realised I had indeed put the dizzy in the wrong way round.....Doh!!
Firing stroke on cyl 1 has NO VALVES MOVING during it's firing compression (up) and stroke (down) as a double check.
could be flooded, take plugs out and make sure they ain't wet....
Edited by RCK974X on Wednesday 2nd May 21:12
FWIW...
The thing we've all done wrong.....are the plug leads on correctly?
If it has not fired at all I would not expect it to be fuel unless it is very old - use fresh. If its been standing have you cleaned the carbs out and made sure they're Ok?
Are you SURE the cam is timed correctly? Were you turning the engine the right way when you timed it? Are you sure its on the correct stroke? Its remarkably easy to cock up - I speak from experience
Best of luck
The thing we've all done wrong.....are the plug leads on correctly?
If it has not fired at all I would not expect it to be fuel unless it is very old - use fresh. If its been standing have you cleaned the carbs out and made sure they're Ok?
Are you SURE the cam is timed correctly? Were you turning the engine the right way when you timed it? Are you sure its on the correct stroke? Its remarkably easy to cock up - I speak from experience
Best of luck
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