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Triumph TR6 - No start for me
|It is about 6 months since I started the rebuild, and I finally declared myself ready to start up today. The olly problem is that it doesn't wasnt to start. Let's assume that I won't feel so fed up after I take a break for lunch... |
What is the order to check things? I set the timing at the value recommended by Jeff at Advanced Distributors when he rebuild the distributor. Number one lead comes off at the 7 or 8 o'clock position as you look from the side of the car, which I think is right. I set the timing with number one and two valves closed (rockers parallel and lifters not lifting) - is that right?
I can't smell pterol, even after several failed attempts at starting. Is there a way to test for fuel other than to pull the hose off and turn over to see if petrol pours out?
How about testing for spark? Brand new plugs, Magencor wires, new Lucas cap and rotor, and as I mentioned the distributor was rebuilt by a specialist, so I figure he probably knows what he is doing with the condensor and points. Is the best way to remove a spark plug and hold it near to the block to see if it sparks? What do I hold it with? Doesn't seem very safe...
I would apreciate any thoughts or advice. I had such high hopes.
|Alistair, pull a spark plug, put it back in the plug wire, while holding only the spark plug wire boot, touch the plug to any handy ground and turn the key. If it has spark, you will see it right away jumping the gap. Pulling no. 6 and grounding to the end of the head is easiest because it is a shorter reach to the key. If you have spark, dribble a little fuel down each carb and try it again. If it fires and quits, try it again, if it does the same thing, check to see to make sure that you are getting fuel.|
When you say number one lead comes off the dist at 7 o'clock I assume you also mean the rotor is pointing to that lead position when cylinder #1 is coming up on compression. The position of both at 7:00 looks correct.
When you say you set the timing with #1 and 2 valves closed do you mean the intake and exhaust valves for cylinder # 1 are both closed.
To be set up you should have:
-#1 at top dead center on compression stroke.
-Exhaust and intake valves closed (cam lobes not pusing on either one)
-The distributor rotor pointing to # 1 lead.
If I understand you correctly that's what you have.
Did you check for spark as Rob describes.. dribble the fuel?
If I have missed something hopefully someone else will chime in.
Let us know.
|HP Henry Patterson|
|Thanks for the suggestions guys.|
I checked for spark with number 6, and there was a spark - looked pretty weak, but it was very bright in the sun, so probably okay.
I then began to suspect the fuel pump (which I took apart to rebuild but found it was non-original so had to carefully reassemble the old parts) so I removed the fuel hose at the connection to the carb line and when the engine turned petrol came out, so I guess the pump is working. I didn't try putting fuel in the carb yet (had to be at in-laws for the afternoon) so I will try that tomorrow.
It seems odd that the car doesn't even begin to sputter into life. Even if I had the timing off completely surely with a spark and fuel there should be something? I put new needles in the carbs using Nelson Riedel's recommended start position (one turn back from the stop, as I recall). It looks like the air pistons won't move just with the starter - could that be the problem? Even after a lot of crankling there is still no smell of petrol.
Thanks again, and any other suggestions would be welcome!
If the timing is off enough it could push air into the carbs rather than draw it in to the cylinder. Just off the top of my head... If you we're 180 deg off the cylinder could be going up while the intake valve is opening but on these engines I don't know if the piston would smack into the valve or not. You might try putting your hand over the carbs, while someone cranks, to see if it's sucking in like it's supposed to.
Again, that's off the top of head so I may be wrong but it seems logical.. I usually have to sit down with a beer do some "cypherin'" to figure that stuff out.
Good luck and keep in touch.
|HP Henry Patterson|
Was your new cam a performance cam with timing instructions and a degree wheel? Or was it a stock cam with no instructions or degree wheel (like mine)?
|HP Henry Patterson|
Check some of the following- it doesn't take much to be out and not get any firing of the engine.
As Henry suggests, the rotor should be set when piston 1 is ready to fire (both valves closed) . It is possible to be 180 degrees out if you set the rotor and piston 1 was on the intake stroke.
When setting the timing chain did you ensure the timing marks are correct.
Squirt gas directly into the carbs while cranking- if the engine does not fire at all- sputter or other wise- you have a timing/ignition problem. If it does, then you probably have a carb/fuel delivery problem.
Check the compression. If the valves are not closing properly, you will not get it to run. No compression will be a sign of valves not closing properly.
These ar ethe things I woudl try to narrow down teh problem.
A word of caution. You are getting some good help here and I hope you get her going.
Remember you are dealing with a very combustible/explosive chemical. Use all caution and do not do this in an enclosed garage. Sorry if I am pointing out the obvious.
This is a little close to home for me. When I was a kid, a friend blew himself up when he was 13 while working on an outboard motor in his basement.
My son last week just about did the same thing while trying to start a boat engine. He said it really scared him. He burned off his eye brows. Matt said the explosion was right in his face. Both the Canada coast guard and the town fire department where there. I think safety just became a little more important to him. Matt bought 2 fire extinguishers that same day. One for his house and the second one he will use to teach his 2 kids how to use it.
Sometimes we get complacent and forget about safety.
Thanks for all the ideas- please keep 'em coming!
I didn't get back to the car yet but I spent some time thinking about anything I could have done wrong.
I set the timing to 12BTDC - the recommendation from Jeff was 10 to 14 BTDC and I have the little adjustment wheel so I figured that was a good starting point. I know thatthe standard is later than that - could that be enough to prevent start-up? Easy enough to move it to 4BTDC and give it a go, I suppose. He recommended no vacuum retard (no vac advance on a '75). The more I think about it the more convinced I am that the distributor drive gear is set correctly, but if I don't get anywhere today then I will take it out and start again - out of interestm, if I take it out how do I get it back in oriented correctly with the oil pump in place? Just a matter of trial and error?
The camshaft is a Goodparts GP2, and I set it using a degree wheel. I got it pretty close to spot on as far as I could tell. Obviously it was the first time I have done anything like this so I could be totally off, but the opening and closing values are as close as Richard Good expects them to be. I really will have to look at the numbers again and watch the lifters to make sure I am on the right part of the stroke with the distributor. Maybe the different openings for this camshaft have thrown me off on stroke.
When you say squirt fuel into the carbs, exactly what are we talking about? A small syringe? Into the opening of the carb or lift the piston and squirt towards the butterfly?
Rick - fear not, I am not quite stupid enough to mess with sparks and loose fuel in the garage! Saying that I was stupid enough to try to change the fuel filter from underneath without clamping the hose at the tank. Only half a pint or so spilled, most on my arm, and two doors open to get air flow, but I didn't even turn the lights off for the night.
Right, I have a deck to stain before the wife gets tired of telling me to do it, then back to the garage (well, driveway!).
Thanks again for the help
Good point Rick!!
Since you have a Goodparts cam and all the instructions there's a good chance you have it right.
One simple test you might try is hang a piece of paper over the carb intake and have someone crank the engine. The paper should be sucked toward the intake.
Also, in line of your own suggestion, if you have a little pen light you can see the piston travel through the spark plug hole. With that you could watch the entire cycle of cylinder #1 while watching the valve rockers. As you rotate the crank (The direction that makes the distributor rotor turn counter clockwise) watch for the intake valve to start openening.. of course the piston should be on the way down. As it starts to come back up both valves should start to close for the compression stroke. Approx. when the piston gets to the bottom the exhaust valve shoul start to open on its way back up. If all this looks good then it should at least pop when trying to start..even if your timing is off a bit. Oh yeah.. and while your verifying all this keep an eye on the rotor.. somewhere around 12 deg. or so of TDC compression the rotor ought to be close to the #1 cylinder wire on the cap.
Let us know...
|HP Henry Patterson|
You can use an eye dropper or syringe (a milliliter or so) and just squirt it in the carb. But As Rick suggests, and you recognize- you are dealing with a flammable explosive material. A safe way to do is squirt it in , then crank engine when you are away from the carb intake. Or rig up somthing so you can stand well aways and do the squirt. All you are trying to do is see if direct fuel gets the engine to run. If it does, then fuel supply/carbs are not doing its job. If it doesn't then ignition/timing is not doing the job.
A missed time engine can cause a backfire out the carbs.
If the boat motors Rick refers to were 2 cycle, there is a higher risk of flashback since the intake and power strokes are basically together. A 4 stroke is separated by the compression stroke.
|I tried a couple of things this evening and I am even more depressed with the whole thing! |
I checked the timing - the inlet valve for cylinder 1 closes, then another half turn of the crankshaft or so brings us to TDC, and that is the point when the rotor arm points at the number one lead. I changed the timing to 4BTDC to be sure that I wasn't too far advanced. No joy.
I squirted 1 ml or so of petrol into each carb using a syringe, then cranked. Nothing. Not even an attempt to fire. Before I did that I lifted the pistons up and touched the needles (new) and they were coated in petrol, so there is fuel in the float chambers anyway.
I really don't understand what could be wrong. I guess I will check the valve clearances again, though I have checked twice, and they are bigger gaps than for a standard cam, so I can't believe that I am not closing the valves fully. I guess I need to find a compression gauge to be sure.
I am tempted to just start again with the timing. I feel like if I take the distributor drive gear out and start again I might somehow do it better this time? I am not sure how exactly, but I am running out of ideas. Well, I ran out of ideas the other day - I am now running out of your ideas!
Once again, thank you for your help.
Sounds like a fundamental problem somewhere. On my previous car, a 73 MGB, after installing a new rebuilt motor, I connected the plug wires assuming the rotor turned clockwise (like the crankshaft). It still started and ran, albeit somewhat roughly. On seeing the light and making the correction it ran much more smoothly!
Stick with it.
Have tried to "Bump" start the car yet? I had to use this method on a crankie Hillman Hunter GLS, even though it ran rough it served two purposes 1. it showed that the engine will run, 2. that my timming was out? This may be a quick way to find out out before you have to go and pull things apart. I guess that you have checked your head gasket?
Update on my spring/summer work....still waiting for the Soda Blaster to appear and the welder has gone to Alberta to Fort Mac$$$$. So in the meantime I am using aircraft grade chemical stripper to peel away a top coat of very thick paint, yuk.
You've verified spark, fuel to the carbs, timing of the cam to crank, and timing of the distributor rotor.
Not much else.
It should of course pull fuel in (unless the rings are realy bad but that's not likely). As you say a compression test should be next. You could also try holding the piece of paper over the carb intake while someone cranks (like I mentioned earlier). Then you'd see if it's sucking air and hopefully fuel.
Is it posible the rotor is in the wrong position relative to the lobes that the points ride on? Are you using points? I'm just thinking a long shot here and maybe the spark is actully going off at the wrong time... like the top of the exhaust stroke. Although you'd think it would pop out the exhaust. Again it's a long shot and is something worth checking before doing anything more complicated.
If all that checks ok then I'm outta ideas!!
|HP Henry Patterson|
A easy way to check for compression is remove the rotor in the dist , pull out the easiest to reach plug...#6 and crank her over ..try plugging the spark plug hole with your finger..it should be pretty strong against you when it reaches compression stroke...Even if you don't plug it it will make a definite sound of compressed air.
You have fuel at the carbs so I think your problem is electrical as in not a good enough spark / make sure the cap is good..is the little contact inside that meets the rotor broken or missing ??..is the rotor new ?...When doing the spark plug test it should be a strong spark with a clear cracking / sparking sound
|I borrowed a compression gauge from Autozone and just did the test - all cylinders between 110 and 120 (psi?) though as I typed that I remembered that I was supposed to hold the throttle open and I didn't. I don't think that should make a difference for the purpose of this test, though, should it? |
I also did the spark test again and managed to watch the spark for number one cylinder in a darkened garage and it happens between the inlet valve closing and the exhaust valve opening, which seems right to me. It was happening too quickly to be certain of the exact timings, but I could see the rocker arms move well enough to determine that the spark seems to be on the right part of the cycle.
Given that I have compression and properly timed spark I have to assume that something is wrong with the carbs. The paper test showed that air is indeed being sucked in while the engine turns over, though not at a great rate - I guess that is because it is just cranking on the starter.
Speaking of the starter, I have a new gear reduction starter on the engine - would there be any point swapping that for the original Lucas starter? At this point I am ready to try pretty much anything. I just sent my friend to get some starter fluid in the hope that that will be more effective than the fuel spray - I did that test again and thought I heard a slight "splutter", and I wonder if maybe I am being too conservative with the fuel I spray in. Why I think starter fluid is a better idea than squirting more petrol into the carbs is anyone's guess. Maybe just the fact that it is called "starter" fluid gives me some sort of hope.
Well, back to it. My plan for tonight is to try the starter fluid and if that works (and probably if it doesn't!) I will change back to the original needles in the carbs. It fired right up last year after I rebuilt the carbs using the old needles, and the new needles arrived about 2 days later having been on backorder for months. I figured it was a good idea to fit them now, but maybe I was wrong. Easy enough to try.
I am scraping the bottom of the barrel now, ideas wise. Any other thoughts would be gratefully received!
How about the mixture? Either too rich or too lean may not fire at all. Are the spark plugs wet or dry?
When you changed the needles did you turn the adjustment screw clockwise to richen? I know the needle direction for adjustment is sort of counter intuitive.
This may be redundant but I'm trying to give you some ideas to think about... That's about all I have.
|HP Henry Patterson|
|It runs! I found the problem - it was the nut that holds the steering wheel. Actually it appears that in my rather amateur efforts to set the timing I was turning the distributor too much, and so instead of firing number 1 it was firing number 4. I think that it still makes sense that I saw the spark at number 1 spark plug between the inlet and exhaust valve movements, but it was moving fast enough that I missed that it was about 120 degrees off. Somehow it never occurred to me that there would be a mis timed spark in that same time frame. |
I actually took the distributor and its drive wheel out to see if the timing was off somehwere (if only I had noticed that it was the distributor cap!)and "while I was in there" I made up a pump priming tool because I was worried that all the cranking on the starter was doing the engine no good. I made up a tool to turn the oil pump and spun it up to about 20 psi on the gauge. Now I may have a problem with the rocker shaft - I am not seeing any oil come out of the holes on each rocker arm, but that's a problem for another day!
I am very relieved to finally have the thing running, and I am happy to admit that I am an idiot. It is too late to do the 20 minute break in for the camshaft now, the neighbours might put up with my Monza exhaust during the day but at 11pm I can see how they would find reason to complain!
Thanks again for all the help and advice - it was much appreciated.
This thread was discussed between 25/05/2008 and 28/05/2008
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