Alright so I just installed Toyota COPs in my car as the OEM ignition was breaking up badly around 6300 RPM. The cops are wired with Hydra 2.6 to run direct fire sequential. The car runs great in most circumstances, unfortunately I'm getting misfire now around 4500 RPM. It doesn't happen every time but its consistent enough. It also seems to happen in other areas of the rev range. In my logs you can see areas where the RPM drop 50-100 RPM before returning on its normal course. The bad breakups drop 100-200 RPM. My plugs are gaped to .040 so i cant imagine I would be getting spark blow out. My dwell settings are right about what Jason and most others recommend on the multiple threads. I was not having any misfire issues on the OEM ignition prior to this (in the lower rev range that is). I've attached a log for reference. I don't see anything that shows me the 4500 RPM misfire is related to knock or bad AFR (but I am still pretty new to all of this so i could be wrong), As for knock, now that i am able to rev past 6200 RPM I need to make some changes to timing. I Also need to recal the knock retard as I think I'm getting a little retard for events that aren't true knock.

Let me know if you have any ideas as to what may be causing my misfire issues.

this is a smaller datalog that shows the miss pretty clearly around 4400RPM.

 

Alright so I thought I may have jumped the gun making a thread on this. I thought I fixed the misfire byincreasing the dwell so that it was at 2.5 in the battery voltage range the car typical is driving in, which on my Hydra is around 13.3V. Hydra is known to read lower than actual voltage from the research I've done. I don't know why. The way my Dwell settings were had Dwell around 2.2 in that voltage range.

I also gaped the plugs down to .035. I should be able to run the .040 based on what Ive seen on here, especially at my boost level but oh well. I took the car out and didn't notice any misfires in various load ranges.

But then just a few minutes ago i took the car out again it it was missing just like before. Typically around 4000 RPM (likely because thats where I tend to be when I'm hitting full boost). No idea if this is blowout, bad dwell times, bad wiring. Kind of at a loss.

 

I would first check if one or more of your coils is bad. I've had times where even new coils were bad. Just because a part is new, don't assume it's good

 

I'd investigate with buying a new coil as well. Just swap out one at a time to see if you can isolate a bum one.

 

I will test the coils today when i go home. I have a feeling they will come back good though as the car runs well most of the time.

Is it possible I need to run a capacitor and/or extra ground wires? Seems like that was the early wisdom but has since not been deemed necessary.

I did notice one of the coilpacks was pretty filthy inside (I bought them used). When I removed it from the plug it left grease and grime all over the spark plug. Also seemed like another of the coils had some oil in/around the boot (not from my car). I supposed dirty coils could create some misfires.

 

You and I are chasing the same problem. Check my thread. I have tried: new coil packs and cas. Next is plugs, wires and connections were my cas and crank a s was wired in.

 

It's not that the coil is completely dead or working. Under stress, the coil will cut out. That is the problem with a couple coils that I had. Especially if they are used, I would consider getting another just to test. If it doesn't work out, you have an extra set just in case. Some times they'll work just fine under normal circumstances, but if things heat up or you're stressing the component, that's another story. Extra coils are worth the investment anyway, as is cleaning them :P

 

How are they wired? Butt connectors, crimps or solder?

 

I know it's probably no help, but I've been battling with a random stumble / misfire on my Hydra FM2 car. Heck I went to LS coils because I assumed a bad coilpack, stumble is still there. Mine is very random, I need to try and get a log of it. I'm wondering if there is a wonky cell value somewhere in my map (might be something you want to double check before throwing any parts at it).

 

they were twisted, soldered, and shrink wrapped. Not the best solder job. My iron starts melting insulation before the wire gets hot enough to melt the solder

 

I'm just wondering if there's an intermittent connectivity issue with temperature. I had a solder joint break on me, but was held in place because of heat shrink. It's hard to test for continuity when it's all so intermittent.

 

yea I've been through the map and don't see anything blatantly off. It's also the same fueling and timing as what I had with the oem coils.

When I went to remove the boots on the coils two of them were pretty dry rotted. One ripped in half. Both had some strange dried glue looking build up inside the boot. I bought two replacement boots and thoroughly cleaned all the crap out of them. Also but in fresh plugs since they are only 10 bucks

i will take the car out shortly. I'm hoping maybe I was getting a short under heavy load from the cracked and dirty boots

 

Alright good news, I thoroughly cleaned inside the coils, contacts and boots and replaced the two dry rotted boots, As I mentioned before they had some strange build up inside them that almost looked like dried glue as well as just general grit and grime (I really should have looked at them more closely before installing them to begin with). I put some dialetric grease on the porcelain portion of the spark plug hooked everything back up and tested the car out. No misfires at all. To verify I had found the issue, I gaped the plugs back to .040 and lowered my dwell settings in hydra back to where they were supposed to be (based on other threads on here). Took the car out again and tested under various conditions. No misfires at all, pulls strong in all gears/loads. I am pretty damn glad that was the issue and I'm not having to chase something in the wiring harness or ECU.