Author |
Message |
Avery Wise
New User Username: hans3
Post Number: 15 Registered: 08-2017
| Posted on Tuesday, 02 July, 2019 - 20:32: | |
Does the Opus sytem have an integral mechanism to cut ignition at redline? I was exercising the 76 Corniche recently and experienced bogging or cutting-out right after the floor kickdown was engaged at highway speeds ~100 km/h. I was probably close to redline but without a tach could not confirm. On one occasion there was a backfire upon lifting off throttle. At no time did the car stall, but it took several seconds for the bogging to clear. Thanks for thoughts. |
Brian Vogel
Grand Master Username: guyslp
Post Number: 2875 Registered: 06-2009
| Posted on Wednesday, 03 July, 2019 - 02:44: | |
Avery, To my knowledge, no. And what you describe, including the backfire, is precisely what I had happen when my Lucas Opus distributor was days from biting the dust entirely. One can buy either replacement distributor electronics (Pertronix is one often used) or I've actually found, though not used, instructions for rebuilding the electronics in an Opus distributor: Repairing and Modifying the Lucas Opus Ignition 35DE8 Module You do not want to find yourself in the same situation I was in when I started the following topic: A Christmas FTP!! . . . Brian |
Mark Aldridge
Frequent User Username: mark_aldridge
Post Number: 618 Registered: 10-2008
| Posted on Wednesday, 03 July, 2019 - 03:48: | |
Avery, check that you do not have a broken wire on the OPUS unit,where they enter the sealant on the unit. The continual movement of the advance retard unit causes the wire to fracture and become intermittent. Mark |
Martin Taylor
Experienced User Username: martin_taylor
Post Number: 150 Registered: 07-2013
| Posted on Friday, 05 July, 2019 - 17:09: | |
Much more likely you only have one fuel pump running and your carbs emptied out under the load |
Brian Vogel
Grand Master Username: guyslp
Post Number: 2879 Registered: 06-2009
| Posted on Saturday, 06 July, 2019 - 00:00: | |
Backfires are extremely rare if fuel starvation is the issue. SRH33576, unbeknownst to me, was running on one side of the dual pump for over 3 years when I acquired her. The discovery of that fact was entirely accidental, and probably never would have happened if a completely unrelated issue had not occurred, but where I suspected the possibility of fuel starvation. Brian |
Avery Wise
New User Username: hans3
Post Number: 16 Registered: 08-2017
| Posted on Tuesday, 13 August, 2019 - 05:30: | |
Attempted to post an update yesterday but it didn't go through. On my next outing the car FTP'd upon exiting the garage. Timing light revealed no current through sparkplug wires on cranking with current (very rapid flashing) only though the coil-dist cap wire. Giggling the wires to the black capacitor within the Opus unit somehow allowed the car to start again. During road test there was no cutting-out at high rpm or backfiring. Thanks for all replies thus far. |
Jim Walters
Frequent User Username: jim_walters
Post Number: 264 Registered: 01-2014
| Posted on Tuesday, 13 August, 2019 - 06:09: | |
If you have no spark at plugs but spark at the coil to cap lead then your rotor is failing. Flashing of the coil to cap lead indicates the OPUS is switching the coil to fire. Replace your rotor or at least carry a spare to replace if it quits on you again. I'n not saying the OPUS module wasn't at fault, but the flashing you describe by using your timing light is the classic rotor failure scenario. SRH8505 SRC18015 SRE22493 NAC-05370 www.bristolmotors.com |
Alan Dibley
Frequent User Username: alsdibley
Post Number: 204 Registered: 10-2009
| Posted on Tuesday, 13 August, 2019 - 17:31: | |
Quote: - "but the flashing you describe by using your timing light is the classic rotor failure scenario. " - often caused by people who still will insist on checking ignition faults by having plug leads disconnected while the engine is running. The spark energy must go somewhere, so it tracks across or inside somewhere that it should not, and burns a track through the insulation. It could have been started down the failure path several owners ago. Sorry to repeat one of the bees in my bonnet. Alan D. |
Jim Walters
Frequent User Username: jim_walters
Post Number: 265 Registered: 01-2014
| Posted on Wednesday, 14 August, 2019 - 02:27: | |
As Alan says the spark energy has to go somewhere. Spark plug leads should never be pulled off a running engine to check for spark. Use a timing light or a spark tester tool. SRH8505 SRC18015 SRE22493 NAC-05370 www.bristolmotors.com |