TR2/3/3A TR3 hard starting, but has been running ok

[txtr3]

It was a beautiful day here in Dallas, a perfect day to take the TR3 out for a drive. Sadly, it wouldn't start. Quite depressing. /ubbthreads/images/graemlins/frown.gif

I'm a relative novice when it comes to working on cars. I have a strong technical background, and understand the basic theory of how an engine works. But when it comes to the details, I just don't have a lot of experience.

I've searched through the forum, and found a few leads I'll try, but I thought I'd throw out the particular symptoms and see if y'all can provide some advice.

Symptoms:
-- Today, hit the start button and the engine turns over, but it never fires up; by the end of all my attempts to start it, the battery is very weak
-- About 3 weeks ago, it took a long time to start, sputtering a few times before it finally got going
-- Before that, it would usually take a little while to start (10-20 seconds), but I figured that was the time it took to fill up the float bowls (I didn't usually use the priming lever on the fuel pump). This slow starting was after it sat in the garage for at least 1, up to 6 weeks. This part seemed pretty normal.
-- In the past, after it started the first time, it would run great, and start easily for the rest of the day

Additional Clues:
I checked what I could think of in the limited time I had this afternoon:
-- Standard starting procedure: pull choke knob, sometimes/rarely prime the fuel pump, push start button.
-- Points gap ok
-- Float bowls full (didn't check the float valves, but those have been ok in the past)
-- Valve clearances almost ok (intake valves all a little tight, so I set them to spec, but no change in symptoms)
-- Plug gap ok, but the plugs are black. It's been about 1.5 yr and around 500 miles since they were changed; but the engine has 135k miles; it has decent compression (or at least it did 1.5 yr ago), but does probably leak some oil into the cylinders. The plugs seem to be covered in a thin, even layer of soot, but then I don't know what is normal build-up for plugs (see how the lack of detail knowledge comes in)

Suggestions I've gathered from other posts on this forum:
-- Could be the plugs. I've seen some references to starter fluid, and I take it this could confirm whether there is any spark at all. But even if there is, I guess it could still be the plugs.
-- Could be the battery. But could a weak battery be able to power the starter, but not provide a good enough spark?
-- Could be the carbs. Although I checked the fuel bowls, and I could hear air being sucked in, I don't know for sure that the jets are actually feeding fuel in.
-- Could be coil/distributor. Other than cleaning the distributor and checking the connections, I really don't know how to check out anything in this area. I don't know anything about checking/setting timing. Also, are there any useful voltage or current measurements that can be made without an oscilloscope?
-- Could be bad fuel. According to a recent post, bad fuel could cause similar symptoms. I doubt this is the cause; the fuel's not old. It is possible that moisture has condensed in the tank, though. It's only been driven once in the last couple months, and there have been some really humid days.


So, whadda ya think?

Thanks,
Jiri

/ubbthreads/images/graemlins/driving.gif <-- Hopefully me soon

 

[Banjo]

TxTr3 first check for spark.Charge your battery back up, remove a plug or grab a spare ,stick it in the end of a plug wire (any plug wire) lay the plug agenst the engine(secure it so you won't get shocked) and see if it flashes while the engine is cranking.if you Don't see a spark or if it's a pitiful yellow spark then suspect the Ignition system. if you do see a spark, Try cleaning or better yet replacing the plugs. if it starts right up then I would suspect that you're running rich. this would slowly foul the plugs and cause hard starts. this may give you somewhere to start. p.s. bottle some of those nice days and ship 'em up here so I can pour 'em on my TR snow drift

 

[AltaKnight]

Hi TxTr3, does it even sound like it's making any attempt at starting as it's turning over?
If it sounds like it's trying then it's likely a fuel problem, prob too rich from your description, hold the gas pedal on the floor as you try to start with just a little choke on.
If it is'nt even trying and just sounds like it's grinding away getting nowhere then it's a pretty good bet there is no spark or as Banjo says a weak pitiful one.
Get 4 of your best friends give them a plug lead each to hold and try cranking it, if they all jump in sequence ignition is ok (I'm only joking here, don't try this at home) seriously Banjo has the right test shown above.
A so so battery can crank the engine but give so much juice over to the starter that there's almost nothing left for the rest of the car including the coil, voila, weak spark, no start. Try a known battery there, someone on this forum suggested taking the wife's battery out of the minivan, if it works you've solved the problem, keep the good battery in the TR3 and the wife won't ever find out at least till next winter!

 

[txtr3]

Couldn't find 4 willing friends, so I had to try the spark test Banjo's way. It did spark, and looked more blue than yellow, but I changed the plugs anyway. The (not so) old ones did look, well, black.

[Another picture of the plugs]

With the battery recharged, the starter sounded strong again, but still it wouldn't start. It never sounds like it's igniting.

Next, I sprayed a quick squirt of carb cleaner in the front SU, while holding the start switch... Fired right up!

At idle (around 900-1000 rpm), it would start to stutter (but it was cold and I didn't have the choke on). I let it run and warm up for a while in the driveway, then drove it around the block, where it still hesitated just slightly at low rpm's.

What does this all mean? Fuel? Spark? Timing? All of the above? /ubbthreads/images/graemlins/confused.gif

 

[aeronca65t]

Weak spark, rich mixture, bad timing or even low compression can cause sooty plugs, so you may have to look at several areas.

Hard starting mixed with decent running is sometimes related to valves. Be very sure that you adjusted them correctly and if in doubt, it is better to have them a little loose.

Be sure that the choke mechanism (really, it's a fuel enricher) is turning "off" fully on the carbs. If in doubt temporarily disconnect the choke cable and be sure the linkage is fully in the off posittion.

Check igniton timing with a strobe light. If it is firing a bit too late, it may run the way you describe.

On an older car (like we all have!) a bad starter may crank the car at an acceptable speed but still draw too much from the battery, "starving" the ignition coil for current. Get those four friends of your's to get behind the car and give it a push while you "pop-start" it in second gear. If it starts up fairly easy, you may have a marginal starter. Notice I'm not suggesting that you use the crank starter....I'm still gun-shy about using these after a few bad moments using one on myTR-3 in the early '70s.

Place your car in a dark area in the evening. Using a plant sprayer, "mist" a bit of water over engine and then have someone crank the engine as you watch. If there are sparks jumping near any of the plug or coil wires, you may be able to see them this way. If you can get the car running, you may also want to try this test while it's idling to see if sparks are "a-jumping". If it looks like a Chrismas tree, it's time for new wires.

If have an ohmeter, check the resistance of the ignition wires, especially if they are the "radio-suppression" (carbon filament) type. If nothing else, see if they are all about the same in resistance value. I use the old-style solid core copper wires. They are more reliable plus they have the side benefit of creating so much EMF that they mess up any nearby cell phones.

Examine the inside of your distributor cap and rotor to see if there are any "trace marks" where current is leaking off. And check to see if the distributor shaft is wobbly (this will mess up points gap, making it irregular).

If the points are worn anyway, I'd change them, just to be sure. This will give you an excuse to replace the condensor, which can sometimes act unpredictably with age (that's probably true of all of us).

The original coils in these cars have an internal ballast resistor but this car may have been changed over the years to an external type. Either way, this device is used to allow full battery voltage to the coil (about 14 volts) while cranking. Once the car is running, this device cuts the voltage back to around 9 volts or so (to make the coil and points last longer). Use a volt meter to check the voltage at the coil while cranking and then running to see if thing are in order. You may also wish to check the actual coil for resistance to see if it's within the workshop specs. If the coil is old anyway, a new one wouldn't hurt.

Be sure that the carb floats are not adjusted too high. If this was the case, the float bowls would have a bit too much fuel in them and the car would run rich. On many SU carbs, floats are adjusted so that an 1/8" drill bit will pass between the float lever and float cover when the float is *just* closed. I'm not sure of the spec for your car, but this should be about right.

Typically on these SU carbs, the main jet nut is set at an initial adjustment of 2 turns out (from being fully screwed in). If you are running rich, you may want to look to see if this is in the ball park.

Be sure air filters are clean.

There is a wonderful part of the original TR-3 owner's manual that suggests "de-coking the head" every 10,000 miles (removing the cylinder head and scraping off all the crud that acumulates on the valves and so forth) I'm not suggesting you do this, but it does sort of imply that these big Triumph engines can get gunked up easier than most cars. A reasonable solution is to give this car an "Italian tuneup". That is to say, take it out on one of your Texas-size roads and give it a good run! It sounds like your car sits around a bit and a good run at highway speeds for a few hours would help clean things up. Plus it's fun!

G'luck.

 

[Banjo]

If it fired right up on ether then its probably a fuel problem. I'll add to this post tonight

 

[Geo Hahn]

The suggestion to basically check everything is a good one... lots of things can cause hard starting and using ether can bypass many of them.

To what has been said I would ask what weight oil you have in the carb dampers? Wouldn't be the source of your hard starting but could produce the hesitation you describe.

The sooty plugs could be due to all that cranking you did though something else you said ["At idle (around 900-1000 rpm), it would start to stutter (but it was cold and I didn't have the choke on)"] makes me suspect it is too rich. My TR3A will not continue to run when cold unless the choke is on a notch or 2. If yours can run when cold w/o the choke then I would think something needs adjustment.

 

[Dave Russell]

[ QUOTE ]
If it fired right up on ether then its probably a fuel problem. I'll add to this post tonight

[/ QUOTE ]
One of the "benefits" of using ether is that it will compression ignite. Very little spark is actually needed.
D

 

[Banjo]

Ok, at this point it gets difficult to diagnose long distance. My crystal ball is in the shop. It's very possible with as many miles as you've said it has that the compression is indeed low. You indicated that with the battery charged a spark test produced a good blue spark. If that is true then unless the timing is way off I would suspect fuel. but in rereading the posts I see you state that there is fuel in the float bowls. that would eliminate the fuel delivery to the carbs, but not a problem in the carbs.
So first off check the carbs. Make sure the pistons are free, that they don't stick, espically ath the very bottom of thier travel, make sure the enrichment(choke)levers are moving the full length of thier travel. Ive seen hard starts from cold if the choke levers aren't being pulled far enough due to the cable housing slipping in the holder. also as a side note, make sure to align the two small holes on the carbs with the holes in the gasket and the air filters when replacing them or that will affect your mixture and performance.
If you determin that the carbs are in order and that you are getting fuel through them and into the engine,and it still won't start then on to the compression. Start with a simple compression test. I wont detail a comp. test here as it would take a lot of space, but any good tec sould be able to lend you a hand.
Finally, the only time I've ever hit a persistantly hard starting triumph that I knew was in decent mechanical condition a PO had incorrectly installed a timing chain. It was off by a couple of teeth. The car would start only after A LOT of coaxing when cold. After it was warm it would start on its own wou it still took a while. a readjustment of the chain solved that. Most 4 cyl Triumphs I've delt with are very willing to start even if the compression is a little low.
So basiclly my thought to you is start with spark, then go to fuel, then on to compression.(and if your still stuck then on to a shop) hope I've helped and not confused. And if I'm way off then for pete's sake someone post and correct me. Cheereio Guv'na

 

[txtr3]

Thanks, everyone, for the advice. Unfortunately, I won't be able to get back to it for a few days, but now I've got lots of good leads to check.
Cheers! /ubbthreads/images/graemlins/cheers.gif

 

[MDCanaday]

MY 2 cents is that the simple stuff is often overlooked.Gas can and WILL go bad in a fairly short time making a car difficult to start. If it has set without fuelsabilizer in the tank , get some fresh gas asap so you arn't trying to fix problems that dont exist.....
md(mad dog)

 

[Banjo]

Ah yes, a very real possibility we all overlooked. Good call