Anonymous

The dreaded miss is back.

Here’s where to discuss anything specific about your standard(ish) car or something that applies to the model in general.
Hasbeen
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The dreaded miss is back.

Postby Hasbeen » 22 Sep 2013 14:48

I thought I had beaten the damn miss last year, when I put ring tails on the wires on the coil. The thing behaved perfectly ever since.

With a lot of wet weather the 7 has sat for a couple/few weeks at a time, without use this year. After a fair spell I used it a couple of weeks back. It gave a couple of that sort of hesitation, half miss a couple of times in the first couple of kilometers, then ran perfectly. I thought it may have partially flooded before cleaning up.

It sat until yesterday, & let me know it was not pleased being ignored. It started & ran perfectly, but coughed about 3 times in the couple of kilometers getting to the main road. Once there it happily accelerated to 100Km/H, then cut dead, rev counter on zero, for about 10 seconds. It came back to life with a backfire out the exhaust.

It was just up to full temperature a kilometer or so later, when it cut dead again, this time for about 15 seconds. It came back to life again with a bang, & I noticed the radio had kept playing, so it is not total power loss.

I was about to go home, but decided to keep going, hoping the thing would stop permanently, so the problem could be traced. I dropped it into third, & revved it out hard through the gears, then drove on normally.

The damn thing did 100 kilometers or so then, & another 70 kilometers today, behaving perfectly.

I assume there is a poor connection, or earth somewhere, & it does appear to be only when the thing is cold, & only on light throttle openings.

God I wish it would break down properly, so I could find & fix the thing, it almost feels like the car is rousing on me for not using it enough, & I'm too damn old to be treated like a naughty little boy, by a car.

Hasbeen

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Postby dursleyman » 22 Sep 2013 15:20

My "new" project car did that to me a couple of times. I drove it home about 100 miles when I bought it and it was great. Then later it would cut out at random, instant cut with the rev counter dropping to zero, but would restart immediately. Very frustrating. I found a couple of dodgy connections and thought it was fixed but no, it happened again.
It finally died properly when I got it out of the garage to take it to the bodyshop.
Inconvenient but at least I was able to fault-find properly and it turned out to be the optical unit of the Lumenition. Took me a while with a meter to find that one but their user guide was excellent. Luckily I have a spare (as you do) and away it went.

Nothing worse than intermittent problems so hope you can find the source.

Russ

1980 TR7 Sprint DHC
Dursley
UK

http://tr7russ.blogspot.co.uk/

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Postby Workshop Help » 22 Sep 2013 17:24

Well, the good news the problem isn't in the fuel system.

Question #1. What kind of ignition system do you have?
Question #2. How old are the ignition cables?
Question #3. Have you performed an OHM's test on all -5- of the ignition cables has shown in my article on Spark Plug Wires?
Question #4. Have you inspected the distributor cap for integrity?
Question #5. Is the rotor intact and not carbon'ed over preventing the electricity from trotting on thru the ignition cable?

Finally, Question #6. What's for dinner?

Mildred Hargis

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Postby bmcecosse » 22 Sep 2013 21:26

Rev counter dropping to zero indicates loss of all power to the ignition system - so you need to trace the supply lead and find the damaged wire/loose or corroded connection..... Until then - carry a 'jump connection' so if it DOES fail, you can run power directly from the battery to the coil - and get home...........

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Postby Hasbeen » 23 Sep 2013 00:51

Thanks Russ, & in answer to Mildred's question #1/, I do have a Lumenition system on the car. I'll look at it, but as it has only given the problem when I'm in the drivers seat, that probably won't help. At least I now have a starting point if/when the thing finally stops completely. Did engine temperature have any effect on your problem?

Further to Mildred, the ignition cables are quite young, & test OK. The light wires connecting all the ignition bits are younger than me, but still not young. I have tested them for continuity, but still have my suspicions about them, even with their new ends.

The distributor cap appears OK, & no rotor button to check.

Hasbeen

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Postby Stag76 » 23 Sep 2013 01:34

Hi Phil,

Is the radio on the ignition or the accessory circuit?

Have you checked the ignition switch. Quite often you hear the story..."All I did was turn it off then on again and now it's OK". What they've done is move the contacts that are causing the problem.

I've got a Lumenition unit (minus chopper) if you want to try it.

TR7 Convertible
Sprint Motor
MegaSquirt EFI

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Postby Workshop Help » 23 Sep 2013 02:19

I concur with the assembled multitude. It's the ignition unit. There may be a sort of fail safe mode who's intent is to get you home should a fault occur. I consider those 'burps' a fair warning. Do you carry a spare ignition unit in your glove box, perchance?

Mildred Hargis

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Postby Hasbeen » 23 Sep 2013 04:33

Hi Bruce, thanks mate, but I have a spare, although I don't know how good it is. I picked them both up at a garage sale 12 years ago, this one worked & the other is still on a shelf.

No Mildred, I don't carry any spares. [:)] You see I have a theory about carrying spares. [;)]

I reckon carrying spares gives your car the idea that it is OK to break down. You have to trust your 7 if you want it to be nice. [^]

The only spare I have ever carried was an inline fuel filter, during my rusty fuel tank stage. While I was carrying it is the only time my 7 has stuck me up on the side of the road, with a blocked filter. [xx(] Once I treated the fuel tank, I put the spare filter back on the shelf in the shed.

Since then I have had no trouble with blocked filters, which, if you look at it the right way [:o)] proves that I was only having fuel filter problems because my car knew I had a spare onboard. [:D]

Seriously, does anyone know if there is a test to show that the ignition system is dying, other than one confirming it is dead.

Hasbeen

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Postby Hasbeen » 27 Sep 2013 01:33

I think I could get to hate 80s British Brass.

The thing cut dead 3 times on a little 8 kilometer run to the post office & back on Wednesday. I sulked all day yesterday, then attacked the thing again this morning.

To my surprise I found a bayonet connector, in one of the wires running from the distributor to the Lumenition box of tricks on the inner guard. Why just one of about 6 wires should have one of these things made of that garbage British brass I can't imagine, but it does. It was kind of hidden in a bundle of wires, where they go into a home made bit of a loom.

I sanded the spade, dipped the female part in Bakers soldering flux, the only acid I could find, then washed them up with contact cleaner & WD40.

While I was at it, I cleaned the newish coil ringtails, & cleaned out the distributor, cap & rotor, before firing the thing up, & going for a run.

The little lady purred like a kitten with a belly full of warm milk.

God knows how long this "FIX" will last, it is about the 5Th time I've fixed this same set of symptoms, but one can only hope. I will replace that bit of garbage with something made in Japan when I get to town next. Who would have thought 50 years ago we would ever say that.

So folks, if you are having any electrical problems, look for some bit made of garbage 80s British Brass. It is probably what is giving you your problem.

Hasbeen

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Postby Beans » 27 Sep 2013 13:59

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Hasbeen</i>

... You see I have a theory about carrying spares. [;)]<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
Yes, you Always carry the spares you are not going to need [:p]

<center>Image
<font color="blue"><i>1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)</font id="blue">
<b>[url="http://www.tr7beans.blogspot.com/"]<u><b><font size="3"><font color="red">My full Weblog</font id="red"></font id="size3"></b></u>[/url]</b></i></center>

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Postby FI Spyder » 27 Sep 2013 14:23

If you combine hot temperature and moisture which I think you sometimes get you have maximum situation for corrosion. I know you use dielectric grease before, have you used it on these connections? There is a pump spray you can use to spray on battery connections to prevent corrosion there, that might work. Back in the day, a trick we used to use hair spray on spark plug wires to moisture proof them.

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Postby Hasbeen » 27 Sep 2013 14:46

Spyder I didn't even know this one was there, so no treatment or protection, which is hopefully the problem, & fixed now. However, I won't bet on it just yet.

There is no corrosion as such on these things, just the brown colour that unpolished brass goes. I have had many fittings look the same, & continue to operate perfectly on other cars. There must be something different with this stuff.

Hasbeen

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Postby HDRider » 27 Sep 2013 17:18

I had a similar problem on the Green 79 TR7. It was the ignition switch. I found it by starting the car and then gently moving the key. There was a dead spot right up against the spring for the start portion.

It was just wear on the contacts and new switch fixed it permanently.

Edward Hamer
Petaluma CA

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Postby Hasbeen » 27 Sep 2013 23:50

I don't think that can be the case with mine Edward, as doing something with the ignition wiring has "fixed" the problem, in a couple of instances for a year or even two. I did fit a new switch a few years back.

This is the first time it has actually brought the car to a stop. Another Triumph enthusiast & I were wondering if the problem may be acumulatively. We thought each connector in a particular system may build up a level of resistance which is not enough to actually stop the whole system working, but has the level of resistance high enough to stop current flow with just a slight increase in resistance in any one connector.

The way various functions of the headlight system will fail, [won't raise, go down, will cycle when turned off, light but don't raise, or raise but don't light], but will work OK for a while with just one connector cleaned triggered the thought. We reckoned systems were on the verge of failure, requiring only a small trigger to fail.

The way Spyder goes through a complete system may overcome this, but many of us stop work when a system comes back to life, without doing a full servicing, so leave it ready to play up again.

I do think our high humidity all year round does effect our cars detrimentally. In Oz it is the Jap cars that give least electrical trouble. Perhaps the fact that much of their early market was in the wet tropical parts of Asia led them to get serious about electrical gear earlier than other manufacturers.

Hasbeen

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Postby FI Spyder » 28 Sep 2013 14:15

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Hasbeen</i>

I do think our high humidity all year round does effect our cars detrimentally. In Oz it is the Jap cars that give least electrical trouble. Perhaps the fact that much of their early market was in the wet tropical parts of Asia led them to get serious about electrical gear earlier than other manufacturers.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

I've only had one electrical connection issue with the Toyota. It was blowing headlight bulbs on far side every three months which I put down to poor quality bulbs in after market. Turned out it was arching in the headlight sealed connector. Replaced it with another connector I found at auto wreckers that I spliced in and problem went away. Only problem with Integra is the cheap capacitors they used in the ICU circuitry which blows and affects some of the accessory items. You could replace the English connectors with sealed ones like Beans has done but that would take all the fun out of owning an English car.[:p]



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