• Hi Guest! Being a Paying Supporter is NOT a requirement to participate at BCF. However, subscribing will help ensure we can continue to serve the LBC community for years to come. If you enjoy BCF and find our forum a useful resource...Please consider supporting us by **Upgrading**
    (PS: Subscribers don't see this banner)
Tips
Tips

No Spark

MadRiver

Jedi Knight
Country flag
Offline
Howdy all,
I've had a somewhat frustrating day with my BT7. She hadn't run in a couple of years, but after I drained the tank, rebuilt the fuel pump, cleaned and rebuilt the carbs, and put fresh gas in, she started like a charm. I drove her a bit on Sunday, and then parked her in the garage, quite satisfied with myself.

I went out today to take her for a spin, and she turned over nicely, had fuel, but wouldn't start. She had fuel, but no spark. I checked several plugs. I replaced the coil with a new spare, still no spark. The prior owner had installed a Pertronix ignitor, which so far has been trouble-free.

Any thoughts from the collective wisdom? Thanks in advance.

Bill S.
 

Gliderman8

Yoda
Gold
Country flag
Online
Did you happen to leave the ignition "On" without the car running for a period of time? I ask this because the Pertronix (I have it in my car) could possibly burn out if the key is in the "On" position and not running.
Make sure you are getting voltage to the coil and that your rotor and cap are OK.
 

Keoke

Great Pumpkin
Silver
Country flag
Offline
I agree with Gliderman8:

Do not leave key on when engine is not running , as during testing
 

Healey Nut

Luke Skywalker
Country flag
Offline
Check the little thin white wire on the battery isolated switch
 

Scottswim

Freshman Member
Country flag
Offline
Yes, the battery cut off switch in the boot might have malfunctioned. In the OFF position it shorts out the ignition power to ground, but sometimes it grounds it out even in the ON position. I cut off the wire (white with black stripe I think) at the switch and taped over the end. You would lose the hot-wire prevention, but that was rarely used anyway.
 

MadRiver

Jedi Knight
Country flag
Offline
Yes, the battery cut off switch in the boot might have malfunctioned. In the OFF position it shorts out the ignition power to ground, but sometimes it grounds it out even in the ON position. I cut off the wire (white with black stripe I think) at the switch and taped over the end. You would lose the hot-wire prevention, but that was rarely used anyway.
Thanks for the advice. Do I have to change anything else?
 

Madflyer

Jedi Warrior
Country flag
Offline
Spark Fuel Air that's all you got. Check fuel filter again. try a new wire from battery to coil. Check Dis cap even a small amount of moisture will kill it spray with WD 40 and wipe dry. also try starting fluid in air cleaner . in any order Try with battery charger on. low battery cold oil will take all the AMPS the starter needs not enough for coil also. Try if you can role start and pop the clutch in say 2nd gear. If it ran then it should run now. MF
 
Country flag
Offline
If a Pertronix was installed, the coil grounding wire might have been disconnected (IIRC, the instructions call for a separate ground wire at the coil since Ignitors switch current 'upstream' of the coil, not 'downstream' as with a points system). When I installed a Pertronix, I switched the leads on the cutoff switch so the coil is grounded in the ON position, and open in OFF--same as the big lead to the battery--preserving the 'anti-theft feature (such as it is).

My guess is the rotor, as they can fail suddenly with no warning.
 

jimmyr

Member
Country flag
Offline
Do not jump the battery to the coil as this is not how the Pertronix system works. Measure the voltage at the coil when cranking to see if the Pertronix is pulsing the coil. Otherwise as said previously, the Pertronix system may have failed.
 

MadRiver

Jedi Knight
Country flag
Offline
Howdy all. Ok. I've removed the black and white wire from the battery switch and the coil. She continues to turn over fine, but still no spark.

I removed the Pertronix system with the old fashioned points, condenser, etc. I had lying around. Still no spark. I replaced the coil, and still no spark. I replaced the rotor, put in new graphite into the cap, and still no spark.

I've replaced both fuses, and still no spark at the plugs, or when I open and close the points. This one is a sticky wicket. Any additional wisdom would be greatly appreciated.
 

jimmyr

Member
Country flag
Offline
Try using a voltage tester light or a voltmeter, and determine where the 12V power is missing. The fuse, the coil, the ignition switch, etc. Then trace it back as to why no power. If that is all OK, then look for something inside the distributor that may be broke. Points grounded, wire broke, insulator cracked, etc. The ignition circuit is quite simple, so find out what is missing and correct it.
 
Country flag
Offline
What kind of plug wires are you using, original stranded copper or aftermarket suppression type? See if you have secondary spark coming out of the coil; not sure what you'd use, do you have some spare spark wire laying about? The stranded copper wires with a stock coil typically just used some of the copper wire wrapped back on the wire, with a cap to hold it in place (I put small brash washers on the coil end with a sheet metal screw into the stranded wire to ensure contact). Aftermarket plug wires usually have a carbon core that can be broken.
 

nevets

Jedi Knight
Silver
Country flag
Offline
I've encountered the frustrating no-spark gremlin from time to time. Once, I discovered that the coil to distributor wire was not making good contact where it connects to the coil. On other occasions the problem has been incorrect stacking of the wires/insulating washers on the points post (grounding out).
 
Similar threads
Thread starter Title Forum Replies Date
K TR2/3/3A Testing spark plug wires..... Triumph 11
Gliderman8 TR6 Spark plugs for TR6 Triumph 7
B Anyone have spark advance data for Piper camshafts? Spridgets 1
B TR4/4A Spark plugs Triumph 1
B Resistor type vs non-resistor type spark plugs for 100-6 Austin Healey 17
G Opinion on spark plug color Austin Healey 15
Lin Distributor to Spark Plug lead wire continuity Austin Healey 5
S Spark Plugs Spridgets 2
AUSMHLY BJ8 NGK Spark Plugs Austin Healey 13
B MGB 1972 MGB Project Blue First attempt and fixing no spark and other checks MG 67
AUSMHLY Spark plug wires 7mm or 8mm Austin Healey 21
longbridgehealey Spark plug wires Austin Healey 8
AUSMHLY When to replace spark plugs Austin Healey 1
K TR2/3/3A Anyone running NGK spark plugs? Triumph 26
K TR2/3/3A Spark Plug Gap? Triumph 4
FlyingCat Spitfire Spark to Coil Triumph 23
K Numbered Spark Plug Boots? Austin Healey 25
tahoe healey Spark Plugs Austin Healey 12
Got_All_4 General TR Anybody Hear or Use This Hot Spark System? Triumph 10
mgedit TR2/3/3A Lost Spark Triumph 26
jfarris TR2/3/3A Which spark lug to use - copper/platinum/iridium Triumph 14
S No spark, im in the dark. Spridgets 6
G spark plugs Austin Healey 10
B Spark Plug Wire Caps Austin Healey 16
Sopwith_Camel MGB the mysterious disapearing spark MG 21
S Wedge Need help with TR8 no spark Triumph 7
vickxxx T-Series 1952 MGTD spark plugs. MG 4
S MGA 1956 MGA negative ground, True Spark Ignition distributor MG 3
B TR6 Spark plug gap Triumph 5
toysrrus TR6 Spark plug question Triumph 23
K TR2/3/3A Spark Plug cuts and diagnosing? Triumph 13
M TR5/TR250 No spark... again Triumph 29
G Correct spark plug ends - early BJ7 Austin Healey 1
N TR4/4A no spark in start position Triumph 8
Mink General TR I am a serial killer [of True Spark ignition modules] Triumph 4
R BJ7 spark plug threads Austin Healey 17
SherpaPilot TR6 Single Spark Plug is Burned Triumph 12
M TR5/TR250 No spark on TR250 Triumph 17
Simon TR4a TR4/4A Spark plugs, what do you use? Triumph 4
gbtr6 TR6 What spark Plugs do you use? Triumph 1
steveg Accidentally deleted Spark Plug Issue thread Austin Healey 2
steveg Spark Plug Issue Austin Healey 54
G Help!!! No spark, no start Austin Healey 2
S MGB 1969 MGB No spark to plugs MG 5
R Spark plugs for 61, BT7 Austin Healey 2
M TR4/4A Spark plugs. Triumph 1
S TR2/3/3A Spark plug threads Triumph 10
T TR4/4A What gap on Champion L-87YC spark plugs? Triumph 3
sim Dead spark plugs ? Spridgets 52
eyera3 no spark Austin Healey 7

Similar threads

Top