D15B4 Misfiring unless under load or idle, happened after hitting 6k RPM
Okay so I let someone else drive the car and they did a pull to 6-6.2k in 3rd or 4th gear and after that we noticed that the car now misfires, first noticed it taking off at the lights. The car has been to 5.5k a couple times and no problems.
The car sounds and feels to be running fine while idling and under load, so pulling up hills above 3k rpm it's fine. Its most notable around the 1k-3k range. But will do it at any rpm if the accelerator is down a bit but not pulling. The engine is D15B4 Dual Carb.
Have taken the dizzy cap off and checked it. Pulled each spark plug out and checked it seem to all be okay.
Have a feeling it could be a clogged carby jet? Idles jets seem to be okay. But if this was the case wouldn't it also be a problem while pulling?
I don't think it is ignition, even though it's probably the most likely cause. I'm going to get out the timing light and compression tester tomorrow.
Anyone have suggestion or know if this is a known problem with the engine/hondas? Read that some of the newer hondas get hairline cracks in the coil packs which seems to cause a similar problem. Guess that could be a possibility? All help and suggestions will be greatly appreciated as I want to get it back on that road as quickly as possible.
Many thanks.
Nic