I'm making it WORSE! HELP!

[spineguru]

Well it turns out the reason my car was running rough and the reason it died are not related. The dieing and then not starting was a bad wire going to the coil. I fixed that and the car is running rough (just like before). Here is where the story gets worse and I am not sure what to do.

I checked the points by measuring (.015) and by dwell meter (upper 40's), so that sounds right to me. I do not have a continuity light so I have not static timed. However, I have put a timing light on each cable to see if I was at least getting regular firing. It turns out the firing is very irratic on all cylinders (it very bad on #3). If I put the timing light over the coil cable, it is pretty regular, but it does occasionally have some irregularity.

It is clear from what I am seeing with the timing light and from what I am hearing and feeling with the engine, that there is an ignition problem. The car has a very irregular exhaust note and the engine rocks a lot in the engine bay due to the roughness.

To add some more pain to this, I previously ( a week or so ago) thought my rough running and lack of starting was due to fuel issues and I had messed with the carbs (I know I am not supposed to do that before I elliminate the ignition issues, but I messed up and did it anyway - call it a learning experience /bcforum/images/%%GRAEMLIN_URL%%/crazy.gif). I am getting an occasional backfire out of the rear carb (when I really hammer the accelerator) and is leaking a bit of fuel. The exhasut does have some black smoke, so I think it is rich, but if I raise the carb piston slightly, engine speed decreases (which is the opposite of running rich according to my tune-up guide).

Anyway, it is worse than when I started and I am even a little hesitant to drive it to the mechanic, which is 15 miles away or so.

Some specific questions:

Since I am getting irregular spark at all of the plugs, is there something that would be most suspect? Condensor? Coil? Wiring inside the distributor? The Cap itself?

Any systematic way to eliminate the good and bad parts? I am thinking if I can just get a regular spark, I can fix the fuel adjustments. I think I am not able to undo what I have done to the carbs at this time because of the spark issue. I assume that if the car is not firing when it is suppossed to, the gas does not ignite and could also create black smoke. /bcforum/images/%%GRAEMLIN_URL%%/confused.gif

At this point I feel like I am just randomly guessing (you probably gathered that from the rambling nature of this message) which will probably lead to more problems, rather than fewer. My wife is also about to lose it as I have dedicated most of the daylight hours this weekend to making the car run worse!

So I have agreed to stop for now, park the car, write this e-mail and enjoy a 65 degree Super Bowl Sunday!

If I can manage to swap out a cheap part and get the firing under control, I think I can fix it. Plan B would be to at least get the car running well enough to feel comfortable driving it to my mechanic.

As always, thanks in advance for any help you might provide.

 

[Harry_Ward]

Engine misfires first things that come to mind are;


Distributor points dirty, pitted, or out of adjustment.
Distributor cap cracked, dirty, or tracking (arcing)
Faulty cable or loose connection in low tension circuit
faulty coil
weak contact spring
high tension plug and coil leads cracked or perished
spark plug loose
spark plug insulation cracked
spark plug gap incorrect
spark plug fouled or overheated (black or extremely white)
ignition timing too far advanced


Sounds to me like you should do a complete tune up procedure with known good parts, or close examination of parts, and according to manual instructions.

Oh, BTW enjoy the game.

 

[Bugeye58]

To start with, the dwell should be 60, not 40. Meter each plug wire from the cap to the end and see what you get. Make sure the contact screws inside the cap are making a good connection with the wires, and make sure the posts in the cap are clean.
Jeff

 

[myspitfire]

Do you have AAA?....I was a shade-tree mechanic once,but decided to flat bed-it.One of the MOST satisfying experiances in my motorhead life!And the ride home was on a beautiful summer day.BUT that was an MG experience(whoa!)I'm TRIUMPH-ently smarter NOW.;-)

 

[Tinster]

The easiest things to check first for a "rule out"
diagnostics are the rotor and cap and wires

Take out the rotor and really examine close for
any cracks or excessive wear. If in doubt,
order two new rotors.

Rotor looks ok?

Check the cap real close for any loose plug wires
or worn rotor contact connections inside. If in doubt
order a new cap.

How old are your spark plug wires? Try testing all
the wires by rotating a new plug thru the series.
If in doubt order a new set of wires, they are cheap.

I would try all these items first as they will cost
you only a new plug.

Hope this gets you started toward a conclusion.

d.

 

[spineguru]

Do you have AAA

Yes I do. I recently upgraded to AAA Plus, so the Tow would be "free". I am leaning that way the more I read...

 

[Banjo]

I agree with Tinster. If the spark on the coil wire looks good, then most likely the points, condenser, and coil are working correctly. and if you're getting irratic firing in all the plug wires, I would strongly suspect the cap and rotor.
If the parts are all older, I would replace the cap, rotor and wires.
I'd Start there.
Good luck Guv'na.

 

[Geo Hahn]

I'd suspect points first, but as many folks want to have a spare of everything it is not impractical to try new (and assumed or proven good) parts all through until the offending item is found.

Not ideal or scientific but inasmuch as you can replace the entire ignition system in about 20 minutes and can hold everything you need in one hand then you might ask yourself what your time is worth (not to mention that Constitutional issue of 'Domestic Tranquilty'.

The 'one hand ignition collection', these parts have all spent time in use and are likely to be sound...

 

[Bugeye58]

I agree, George. I've got a similar setup that essentially only gets used for troubleshooting purposes.
Jeff

 

[spineguru]

Meter each plug wire from the cap to the end and see what you get. Make sure the contact screws inside the cap are making a good connection with the wires, and make sure the posts in the cap are clean.
Jeff

OK, I lied earlier when I said I was doen for the day. I couldn't stay away from it completely. No wonder my wife calls the TR3 "Trixie" and says it is the "other woman"! /bcforum/images/%%GRAEMLIN_URL%%/grin.gif

I do have an update. I put an Ohm meter on all the plug wires, measuring from the inside of the cap to the end of each wire (including the coil wire). All of the wires measured less than 1 Ohm (which seems low enough to me), except for one. The #4 cylinder wire measured infinite (i.e. open circuit). I unscrewed the screw and removed the wire and still could not get a reading just measuring the wire. Certainly might be my problem (or one of them).

I also checked the resistance of the low tension lead and some of the other wires inside the distributor. Those seem good.

One thing to note is that it was difficult to get a resistance signal on any of the spark plug wires just measuring the resistance by touching the post inside the distributor. I had to put the probe tip on the screw itself, rather than the post. I could sometimes get a reading if I scraped the post with the probe. Maybe the posts have too much build up. /bcforum/images/%%GRAEMLIN_URL%%/confused.gif

I checked my records and the mechanic replaced the points and the condensor less than a year ago when he helped revive it from its long slumber. It does not look like the plugs, wires, or cap were replaced. The cap looks old (original?), as does the rotor, but neither look horrible in my opinion (although I have no idea what "good" looks like). Nonetheless, you can definately see the wear on the posts where the rotor hits the posts. The plugs look pretty good, but are pretty cheap to replace.

Sooo.... I am thinking a new cap, rotor, wires and plugs. Based on this new info does this sound like a reasonable plan?

Oh, one more thing, assuming that the only thing wrong is the point setting (evidently my dwell is set a little low), and that all the plug, wire, cap, rotor issuies were nonexistent, how rough would it run? Slightly, moderately, or very? I am trying to get a feel for how much of an improvement I would see if we just got it down to the points adjustment. It is quite rough now.

Thanks again. Back to the game....

Thanks.

 

[Tinster]

If you buggered up the carb settings
it might still run ruff.

BTW. Did you check all the vacuum lines?

d

 

[KVH]

A few points here:

a) you can static time that car, and will enjoy knowing how if you don't already. For me, that's always been the best technique by far. Just use your front parking light bulb and a piece of 16 or 18 guage insulated wire. Ignition on. Your manual will tell you how (pointer on the pulley hole, rotor to piston 1, points just opening--light just coming on). I'd use that and not a timing light;

b) turn your mixture screws, both of them, all the way up, closed, then back off 10 to 12 flats which should leave you a bit rich, but OK until finer adjustments;

c) clean all plugs with a wire brush and rag, then reinstall;

d) I'd then clean the spring peg in the distributor cap, clean the rotor, make sure it's properly installed--a good rotor is important and we've all seen defective ones.

Then, be absolutely sure there is no "arcing" occuring from the rear of your spark plug boots to any nearby steel, including your fuel line. Sounds nuts, but it's not. Just make sure the boots are well secured and that no steel part appears too close to the rear of any plug.

Try is all again and see how you do. If that won't fix things, I'd replace that distributor cap, wires and maybe even the plugs.

Something else I'd do. Obsess and check it well into the wee hours of the morning when the wife isn't looking.

Good luck

 

[spineguru]

a) you can static time that car, and will enjoy knowing how if you don't already. For me, that's always been the best technique by far. Just use your front parking light bulb and a piece of 16 or 18 guage insulated wire. Ignition on. Your manual will tell you how (pointer on the pulley hole, rotor to piston 1, points just opening--light just coming on). I'd use that and not a timing light;

Cool idea using the front parking light. Just so I fully understand, where do I hook up the wires? Thanks.

 

[KVH]

This will sound primitive to some, but this generally follows the old Chilton Manuals:

Strip about 2 or 3 inches on one end and 1/2 inch on the other end of a two feet piece of insulated wire.

With a 12 volt bulb, usually the same one from a front or rear lamp, I wrap the 2 or 3 inch bare wire tightly around the base of the bulb and fix the 1/2 inch piece to the coil lead that goes to the distributor. That is the negative lead.

With the timing mark on the pulley lined up with the pointer, and the rotor pointing at plug number one, and with the ignition key turned on and the distributor clamping bolt slightly loosened, you're ready to test the timing. (Of course, you first set your breaker points to the correct gap)

What you do next requires two hands. With one hand, put the contact located on the buttom of the bulb, the hot point contact, on a good negative ground while holding (same hand) the 2 or 3 inch bare wire around the base of the bulb. For a ground, I use one of the two bolts sticking up out of the valve cover.

Then, while holding the distributor body firmly in place, carefully (slightly) rotate the body of the distributor until the bulb just lights--the points just open. That will be TDC. I usually go back and forth to be sure the light first goes out, then comes back on.

When it just comes on, re-tighten the distributor clamp. Never over tighten that clamp. It will deform.

After re-tightening, the rest can be done with the dial, and most people will rotate the dial until one more notch appears on the micro scale. One notch equals 4 degrees, making it 4 degress BTDC, Before Top Dead Center. Some people like the timing slightly retarded for better performance and less pinging, but for your purposes, I'd just leave it at 4 BTDC and address the other issues you mentioned.

Note: You'll get a slight shock when the bulb lights up. You'll know it's all working when you feel that.

Good luck. Let's hear how things worked!

 

[martx-5]

Being that you have an ohm meter, which I would assume has a voltmeter on it also, just use that (DC part of the meter) instead of making up a special test light.

 

[spineguru]

Do you have AAA?....I was a shade-tree mechanic once,but decided to flat bed-it.One of the MOST satisfying experiances in my motorhead life!And the ride home was on a beautiful summer day.BUT that was an MG experience(whoa!)I'm TRIUMPH-ently smarter NOW.;-)

This is the route I have decided to go. Putting it on a flat bed tomorrow. I feel a bit like I have punted, but I think it is the right way to go. I want to get it right so I can enjoy those great Spring days just around the corner!

Thanks to all for your help. On the positive side, I have learned a ton in the last few weeks.