Epic Journey but only on 5 Cylinders

[robmurray]

I am driving my new 1967 2000 Coupe back from Lisbon in Portugal to Marlow in the UK. It is a great adventure and the car is gorgeous. However, the engine is misfiring and I think only running on 5 cylinders with much popping in the exhaust. It turns out that the Dinoplex is in emergency mode so it is, clearly, faulty. I have tried switching it back and this makes no difference. My understanding is that it should still run OK with Dinoplex in this mode. I have cleaned up the distributor cap contacts and the rotor arm which were quite dirty. It ran smoothly for a couple of seconds then the misfire came back. The plugs are brand new and the engine was professionally rebuilt 3000km ago.
Any tips for anything else that might get me going better?
Pic of engine bay attached.
Many thanks
Rob

[frogspawn]

Probably teaching you to suck eggs...
Make sure plug leads are correctly fitted, pushed right in.
Remove plugs and see if one looks "different"
clean points- bit of fine glass paper run between the contacts.
Run engine at night or in the dark and see if one of the plug leads is shorting out.
Remove plug leads when engine running (insulate yourself!!!) does one make no or little difference?

Clean fuel filter - yes I know but you never know.

You do have insurance that gives you recovery don't you?

David

[Dinoswede]

Congratulations to your new Dino Coupe! The engine bay looks nice, so probably, your misfiring problems are an easy fix. When reading your description of the
misfiring engine, I thought of the possibility of badly adjusted carburettors. If the idle mixture needles are set to a very lean mixture, the engine will probably
misfire - and backfire loudly, when letting the accelerator pedal up. It will simply not perform well in most normal driving conditions.
Well, just a thought... Let us know, how the trip - and the Dino - turned out!

Dinoswede

[robmurray]

Hi there
We made it back - all 2481 km, misfiring all the way. We think it is a combination of carbs (it is the middle cylinder on each bank which is not firing and we have compression and a spark) and worn distributor. Im going tonged a specialist to set it all up so I have a good place from which to start my ownership.
The journey was epic and I love the car!
Rob

[beebee246]

Hi, a couple of days ago you were advised the following:
Remove plug leads when engine running (insulate yourself!!!) does one make no or little difference?.
There is a simpler test for a plug that's not firing. Dab your finger on each exhaust pipe (quickly; they should be hot!). If a plug isn't firing, the pipe will be stone cold.
Hope that helps,
Brian Boxall

[The Dutch Dino]

Some has been covered already, but I had a long search recently before I found the cause for my misfire.
-check ignition: remove lead from coil to distributor and it next to metal of body, turn ignition, look for spark.
-your issue is that only one or two dont spark, so check individual plugs. Remove from block, keep it in the plug lead, grounded at block with the metal side, turn engine, observe for spark
-alternatively use an infrared thermometer gun and point it at the individual exhaust pipes of the exhaust header. DO NOT use your fingers!!!! Dino exhaust header can get red hot!!!! Way over 500oC!!!
-I found one or two misfiring some of the time but not all the time. Hard to spot. My problem was the points. I use a modern electronic setup (MSD) and the points are there for triggering the ignition. Problem was that the points did not open fully every time when they were supposed to do so for cylinder 2... Sometimes they did, but not always... I tested the distributor with a test light on the workbench. Easy. Take it of then car. Connect plus and minus from a battery to each side of the points and a lightbulb inbeteeen. Turn rotor and see if light goes out. If not or not every time the points open up, then you'll have a misfire. If so, adjust point (2 minute job), test, and reinstall. Presto!!

But this was all after opening up the carbs, discovering dirt in the chambers, cleaning, reparing bent idle screw, balancing carbs, changing coil, testing compression, checking valve play, cleaning grounds, rewiring gas pump, etc.

But now it goes like never before!

Remember: these cars are not that complicated and quite solid. You'll work you way through and find it and it will probably be something small. And they run fine in emergencia mode also, so you should be able to track the real fault in that mode also. Also balancing the carbs is easy if you follow the normal procedure.