Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) +4 GDI cold start

Maybe pull another plug (or two) and see if they're similarly pristine ... that clean and 1000 miles in would baffle me a bit in my car (albeit an older and simpler engine) .... if they're different put them all back ... start the car ... and with gloves on pull each plug lead off in turn .... you should notice a definite roughness each time (you'll know in a second or two so you can push the plug cap back on and all should settle down ... that plug is suspiciously clean to someone of my vintage. ... if you pull a plug lead and there's no change that will narrow your search to that cylinder..... may as well eliminate a missing cylinder for sure ... only takes a few minutes and it's free!

K

PS ... you might want to hold on that if your car has individual coils on the plug, pending someone confirming that wouldn't harm them (used to pull the coil packs to test this way all the time on my race engines but better safe than sorry.)

Fully concur with Image comments and sage advice.
It certainly seems peculiar.

Sorry to read of your issues Adam. Thought to relate a little story relative to my first motor car, having spent quite a few years as a motorcyclist in my yoof, rebuilding their usually well worn engines... Same thing with my first car being a 1959 Frogeye Sprite. All back in the day when engines were so much simpler..... I was a little disappointed with the performance of the Sprite, and after a week of running it in, I pulled the sparkplugs to find the plug in No1 cylinder had never ever fired...!!! These ware new out of the box Champion plugs as part of the rebuild.. I dug out one of the old plugs that had come with the car, and boy was I pleased with the increase in performance....(-: I had even tuned the engine running on three to tick over at circa 750RPM.... My excuse is that I was more used to listening to rather loud single or twin m/cycle engines, thus did not detect the missing pot...! (-:
Hope a replacement plug solves your issue Adam, but might have thought any such seemingly obvious fault would have been picked up by the OBD gizmology..?
Looking forward to reading you have resolved your issue.

I think Luddite may be onto something. Suggest pulling another plug for comparison. Something doesn't look right there with number 1. Could unburnt fuel have caused the mess on the threads

Thank you all. A friend who's a bit mechanical wondered if there wasn't a leaky valve cover gasket resulting in so much oil on the threads, something to look into, though the way the plugs are located under the central bonnet hinge it's actually a little difficult to get a clear line of site down there!

Luddite, I do see your point about the OBD reader surely throwing off a code if there literally was no combustion going on in cylinder #1? That said, if it turns out to be like your Sprite and in the end I get 33% more HP than I'm getting now it will certainly be a silver lining!!

I like your suggestion of just pulling the lead to cylinder #1 to see if it makes a difference, but as you note these GDI engines are "coil on plug" setups and I will proceed with caution (i.e. Googling) before trying that one.

I will check some of the other plugs tomorrow for comparison as per Luddite and Richard's helpful suggestion.

One note -- the suggestion to blow out the area with compressed air before pulling the plugs was invaluable -- it seemed to blast away about half a pound of leaves, dead bees and a number of nuts and seeds -- my car lives outside in a forest and I suspect some small local fauna are setting up camp in the still-warm engine come nightime!

Your photo shows a modern Iridium tipped plug, they do burn incredibly clean and don't even erode to increase the gap, Ford branded ones are surprisingly good quality - pulled some at 50k from a Focus and they were almost as clean as new 'uns

The days of comparing the old Champion colour chart are wasted on this modern stuff with fancy ECU's and leanburn tech

Jon, thank you -- that is reassuring!

Is the plug really that white or is it because the pic is taken with flash. The insulator on my plugs are just very light grey. The rim of the thread is black, which my dyno man says is because of the ethanol in the fuel.

For me the best way to see if a cylinder is fireing is to spit or dab some water on the exhaust manifold.

Thanks John that's a very useful tip.

I use one of those infra red thermometer things that you just point and press, gives a reasonably accurate spot temp - super useful for lots of stuff (balance your CH radiators at home properly) (is the LH brake drum really hotter than the right ?) and not expensive from the usual online sites