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TR4/4A TR4A Won't Start

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I didn't have a lot of time to devote yesterday, but here's where I am:

a) the coil sparks, so I'm not so sure that's my problem after all. However, the voltage across the coil is still only approx. 11 volts. I also can't see a coil just wasting away during a period of idle sitting.

b) maybe I should pull and clean the plugs since the car sat for 7 months.

c) same thought on the gas; I suppose it's not the best; but I'm not sure what I'd add.

d) my point gap is only .010. However, the car ran terrific before the sitting spell, and I have some kind of performance cam. The PO called it a mild cam, I think from Gilliland. Could the cam warrant a different point gap or should I open it back up to .015?

e) I'm suspecting I should pull the air cleaners and check for fuel at the jets.

Thanks for all the help. I'm still all ears.
 
KVH said:
d) my point gap is only .010. However, the car ran terrific before the sitting spell, and I have some kind of performance cam. The PO called it a mild cam, I think from Gilliland. Could the cam warrant a different point gap or should I open it back up to .015?
Click to expand...
I'm a little confused here; you mention "point gap" (which I take to refer to the distributor) in connection with your cam. That makes me wonder if what you're really asking is about valve/rocker clearances? Ignition points generally should be .014-.016" regardless.
 
No, actually, it's the ignition point gap which is only .010. The proper spec on my TR4A, as you likely know, is .015.

I was only asking whether something done in the design of the cam would explain the points setting. The cam was specially ground by an engine shop in California for the prior owner.

Before I put the car up on jacks 7 months ago, it started every time with a slight turn of the key and was among the smoothest idling cars I've ever owned.

That is why I'm reluctant to fiddle with that point gap until I eliminate the other big items--unless this one is glaring, which it may be.

Thanks.
 
I would change it to .015 now. That should be checked regularly.


As Eric and Phil suggested, if you haven't take the air filters off and shoot a little carb cleaner or starting fluid in there. In my experience after cars sit and don't start it's fuel.
 
Too small a point gap usually won't prevent an engine from firing.

7-month-old fuel usually won't prevent an engine from firing.

A tired battery usually won't prevent an engine from firing.

One stuck float usually won't prevent an engine from firing.

A couple of fouled plugs usually won't prevent an engine from firing.

Well, you get the idea. But of course several of these conditions at once can cause your problem.

My guess is that you won't be able to get at any big problem until you've got more of the basics squared away.
 
Grab an old spark plug, unplug one of yours at the spark plug and stick the old one in the plug wire now hold the little thingy on bottom of the spark plug to the head (Hold the plug with some insulated pliers) and turn the motor over. If it sparks at that little gap, put the wire back on the plug that is still in the engine; put the old spark plug in your pocket. Take off your air cleaners and squirt some starter fluid in and it should start!
steve
 
FWIW, my coil failed while I was at TRfest 2009. Engine ran fine the evening before, was nearly impossible to start the next day. Steve's test showed it was producing a spark, but a puny, weak one. After lots of fiddling and coaxing (including new plugs, points, rotor, condensor) I finally got it to run, but just barely. Drove it into town with it spitting and coughing all the way, even after it was thoroughly warmed up. Got back to the hotel, bought a new coil from a vendor, and it ran great.

A previous experience (many years ago) with weak spark was caused by a bad condensor. Literally driving down the highway, the engine sputtered a few times and died, kind of like being out of gas. Again, the spark plug test showed a spark, but it was weak. Hiked up the road, bought the wrong condenser at a filling station, engine ran fine again.

My point being that it takes more to fire a plug under compression than out in free air. If the spark is weak (voltage low), you may be able to draw one and it still won't start the engine.

That said, since you do seem to be getting spark and the above situations are very rare; I would investigate fuel. Starter fluid or even just spray carb cleaner (the carb cleaner seems to be more flammable than what they sell for starting fluid these days) down the carb throats is a quick test for lack of fuel. If it will fire even just once after dosing with the spray, that is an excellent indication that the problem is fuel.

And problems with the jets and/or float valves getting clogged after being parked "wet" for a few months seem to be much more common these days than they used to be. Apparently gasohol tends to dry into something that looks like hard water deposits rather than the old soft 'varnish'. On my lawnmower, I had to literally chip it out of the main jet with a dental pick! Carb cleaner didn't phase it at all.

PS, one more thing to watch out for : Don't accidentally create a new reason for it not to run while troubleshooting the old one! If you have the points out, double-check that they are properly installed (the wires go UNDER the plastic washer!) And don't do my favorite trick of leaving the rotor laying on the inner fender.
 
IT RUNS GREAT!

Thanks everyone. I found gas in the carbs, so I felt I could eliminate that, but I pulled the filters and worked the jet needles up and down to be sure no issue there.

I then pulled the plugs and found all them a bit carbon coated, with the insulators a bit "caked" on two of them. I cleaned all plugs.

The car then started right up.

I still think about that .010 point gap. It makes me wonder how important the precise gap can be. I always thought that an incorrect gap would throw off the timing. I'll reset it this weekend. (or "if it ain't broke, don't . . .")
 
KVH said:
I still think about that .010 point gap. It makes me wonder how important the precise gap can be. I always thought that an incorrect gap would throw off the timing. I'll reset it this weekend. (or "if it ain't broke, don't . . .")
Click to expand...

Yes, changing the point gap will affect the timing. Of course, you can adjust the timing then to compensate.
 
KVH said:
I still think about that .010 point gap. It makes me wonder how important the precise gap can be. I always thought that an incorrect gap would throw off the timing. I'll reset it this weekend. (or "if it ain't broke, don't . . .")
Click to expand...
Vital to national security? No. But I've always found that the closer to the spec. of .015" the better in terms of overall performance!
 
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