TR6 PI starts with a bang, then dies

[MortenHoyseth]

Guys, sorry about the radio silence from my side. A bit hectic this weekend, preparing for traveling the next two weeks.
I did manage to get a brief test - very temporary setup - this morning (I haven't sent the dizzy yet), unhooking the vacuum spring, fixing the plate. I rotated the base plate to what looks like right (contact point opening, rotor), and it did start Not running beatifully, but I had no time to test and dynamically set the timing, nor did I bleed the injectors after having them all out - and timing the MU - n times.

When I'm back, I will update asap

BIG THANKS TO EVERYONE SO FAR!!! You have been great help !!! Impressed and appreciated

[MortenHoyseth]

...and Peter, yes, Mrs H got flowers Good tip

[MortenHoyseth]

Hi all of you! This thread has been inactive since August due to two reasons – 1) the distributor was sent to Distributor Doctor (DD) for a check and 2) Some traveling was done and on top of that I became a father for the second time, and situation has not allowed for any time spent in the garage.

But there are news on the topic, and since there has been so many helping out on this ignition/timing issue, the least I can do is to update.

It was the distributor. Martin at DD found the problem and fixed it (thanks Martin!!). As more that one of you commented, the base plate seemed to be stuck in the wrong position, and that is correct. Effect of that is that when the point opens the rotor is right between cap point 1 and 4, so I was unlikely to get a spark going, and it could go the wrong spark plug (or none). The reason for this is that the spring from the retard unit had been pulled out of position by 7 mm (damaged), pushing the baseplate CW. Martin comments that this is rarely seen; if the spring comes loose it normally is obvious, but in this case the spring was jammed for some reason, so it looked right. He was also surprised that the engine could have been running at all with such fault. I have no idea when this happened, but I might have damaged it when trying out the electronic ignition. Guessing.

To remedy this, Martin removed the retard mechanism – no need for that in my case. The baseplate is set in right position, drilled and screwed, and a CP type micrometer adjuster is put on.

My system setup might be a bit “different” – it’s a US spec car with 2.5 PI engine (engineno. MH108HE so a 2.5PI saloon for export to Sweden from what I’ve found out) Injection fitted. Stage2 head with a Sprint90 cam. The dizzy is (probably) original to the US car.

So problem found and fixed. Well, I won’t pop the Champagne before I get the engine started, but point (2) above prevents me to test it before next weekend.

So

1. Thanks to all of you for fantastic help on this matter! Highly appreciated and very glad that you never gave up helping!
   My knowledge of timing an Ignition/PI system has increased a lot – still not the widely experienced expert, but quite confident about how things work and should work.
   Hope this thread has helped others as well.
   
2. I’ll conclude this thread when the engine runs.
   

[Mark Davies]

Just had the situation of a heavy midrange misfire. Also, when trying to start a very rough running with a great deal of unburnt fuel in the exhaust. 

Solution was replace rotor arm which had split into two, replace cap as matter of course. Still a slight miss so changed the CONDENSER!  which I had not long replaced... 

Problem seems to have gone

72 CP car with Reworked Lucas.