No spark again!

[Marsu]

I have no spark again!

The Lumenition module and ballast resistor both are receiving 13.6v with ignition on and a bit less when cranking.

The key differences between now and when the car ran last weekend are:
- The brand new battery had drained so it would not crank at all over the five days since last run
- The multimeter registers a constant drain of 0.5v everywhere I test
- The ballast now has the same voltage (13.6v) on each end where previously it was less approx -2.0v at one end to another
- In following the Lumenition procedure to test the ignition module it now registers a constant reading of approx 6.0v where previously it switched from 3.5v to 14.0v (the Lumenition doc says it should switch between 1 and 13v)

I've just fitted a new coil - it's the third that's been in the car recently and it made no change. I've tried my other rotor button and it effected no change either.

HECK! [}:)] - I DON'T KNOW WHAT TO DO NOW?

Should I order another ignition module or fit points and condensor?

I fed up with electrics - why didn't they teach this stuff at school?

[Stag76]

A common cause of battery drain is a failing diode set in the alternator...there is a small brown wire connected to the alternator that carries 12v all the time, and is used to excite it to start it charging. When the diodes fail, the 12v goes to ground and flattens the battery. If you disconnect the alternator plug and the voltage drain is gone then it is the problem.

Luminition modules have a very low failure rate, as they're basically only an amplifier and power transistor coupled to the optical sensor in the distributor.

You could bypass the ballast resistor to eliminate it (running the coil on 12v for an hour or 2 will not cause any damage). If that's OK, check that you have 12v on one side of the optical sensor when the vane is in the eye, and on both sides when it is not in the eye. The fact that the resistor registers the same voltage both sides seems to indicate some type of failure.



TR7 Convertible
Sprint Motor
MegaSquirt EFI

[busheytrader]

I've got Lumenition on my V8. The only problem I had after 19 years ocurred when the connector block's contacts became coated in the usual green powder. That's the red plastic Lumenition connector that connects the dizzy to the main component.

A quick clean up and the chronic misfires disappeared. I'm not a vehicle electrician but it worked for me.

Might be worth a look if you've got the same fitted on your kit.

Adam



TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, S/S Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes all round, Anti- Dive, Strut-Top Roller Bearings, Capri Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 14" 5 Spokes or Maestro Turbo 15" Alloys, Cruise Lights, S/S Heater Pipes, Replacement Fuel Tank. No Door Stickers. Mine since July 1986, V8 from 1991

[FI Spyder]

I've got a vampire drain in my Integra of .3 amp that will drain the Optima battery in three days. (I just remove the fuse that controls that circuit, it's apparently a ICU leak). Not that that will help you in diagnosis, just the time frame that the battery will drain.

Constant voltage sounds like a module problem but clean connections are paramount, no cold solder joints, a close visual inspection under magnifying glass or better yet one of those large magnifying glasses with round flourescent lights around it. (I've got one in my garage you can use if you want to come over)>[:p]
.

TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

[Hasbeen]

My 7 started to develop a slight hesitancy, but only at low revs, small throttle opening, about 2 years ago. This was mostly so slight some people could not hear it in the car. Over about 10,000Km it had me cleaning/replacing plugs, leads, coil etc, & cleaning every connection in the ignition system a couple of times.

Every time I did something the hesitancy would go, only to return in a couple of thousand Km.

Ultimately the thing would dead cut for a second or two, & occasionally long enough to result in a backfire, [tail pipe] when the sparks returned. Still it would not show any fault when tested, only while driving.

By now I was more interested in finding what was causing the problem, than in curing it.

During another contact cleaning session, I noticed a slight bit of discolouration around the base of a bayonet connector on the coil. When I pried the connector open, off the wire, I found some corrosion of the wire, inside the fitting.

After cutting the wire back 1/2 an inch, & soldering all connectors, the problem disappeared, & remained gone.

Check if you have any crimped connectors, or joiners, they may be the problem.

Hasbeen

[Marsu]

This has been a saga!

Over the last week and a bit I took the ostrich approach to this problem. I then picked up the bit went out to kick the tyres again yesterday.

In between I've been thinking hard about about what a B$TCH this car is and how she may look after going through a crusher.

After charging the battery and checking all the connections I had exactly the same situation as reported previously.

I then changed the rotor button, putting the repro unit in that seemed bad before. No change. Next I swapped it for the last "newish" original Lucas one I have. No change. Next I swapped back again and fitted the new (poor quality, IMHO) repro cap and leads I ordered from Rimmers. No change.

At this point I stood back and kicked the RH front wheel hard - my toes still hurt. My local neighbor came over to console me and advise that his wife would prefer me to moderate my language. His name is Peter too, so with this serendipity I unleashed a few more expletives and then apologised.

We commiserated together for a while on the vagaries of women and cars.

I reached into through the window and give the ignition key another tiwst.

The car started immediately!

Spark is now good all the time. I just wich I could ascertain what caused the change!

[PeterTR7V8]

All Peters are named after the saint (of the same name) so tend to be a bit sanctimonious (ie, a prick) at times. [8D] No offense to other Peters. [B)]

Now that it's working you have no chance of fixing it but in future, if all the wires & connections are clean & good, the battery is OK, the coil has 12V & the points/ignition module is pulsing then it will probably be the rotor, dissy cap or the HT leads. The problem with electronic ignition is it can be barstard to diagnose especially if it is an intermittant fault. Maybe you can restore it to a simple points system to help with the diagnosis.





The map: http://tinyurl.com/wedgemap . The blog: http://www.forum.triumphtr7.com/topic.asp?TOPIC_ID=8548

[RadioGuy]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">No offense to other Peters.<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Oh, did you leave that one open for comments.

But, I will not delve into such topics...in writing...[:0][:I]


Maintained on Saturday…Drive on Fun-Day !!! 1976 FHC - 1980 DHC

[PeterTR7V8]

Well, this is where all the Peters hang out isn't it? [:D]



The map: http://tinyurl.com/wedgemap . The blog: http://www.forum.triumphtr7.com/topic.asp?TOPIC_ID=8548

[RadioGuy]

[:D][:D][:D][:D]


Maintained on Saturday…Drive on Fun-Day !!! 1976 FHC - 1980 DHC

[Beans]

<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 Marsu</i>

... I just wich I could ascertain what caused the change!
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">Looks like you kicked it hard enough [:D]
Agree with Peter, make sure all contacts are cleaned thoroughly.
If the fault happens again switch to points and see what happens.

<center>
<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="2"><font color="red">My Weblog</font id="red"></font id="size2"></b></u>[/url]</b></i></center>

[Marsu]

Agree, the toes are still aching.

All connection points are VERY clean, all suspect crimps have been renewed, all wires checked thoroughly.

I've got out my spare 44D and set it up with new points and condensor. The first sign of weak spark I'll pull the lumenition dissy out and fit the spare.

On reflection I am wondering if the issue could be an intermittent fault in the ballast resistor - I'll get a new one as well so as to be ready for the next episode of recalcitrant behaviour from the car.

I used to refer to this car as HOGGY, as she seemed to have a heart of gold, but a new name seems called for such as: an mhuc, y mochyn, domuz, gast, kurwa. Other suggestions welcome.

[jclay (RIP 2018)]

I am sure that you have checked this, but just in case. Check the wire going into the dissy right where it makes a turn as it enters to see if it is worn through. It sounds like something is moving slightly and shorting out. Then when you make changes to the dissy, it moves away again stopping the short.

Clay

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