Fried Toyota COPS, too much dwell?
 

So today my car started running on 3 cyl. I managed to limp it home and pulled the coils. One is melted and was smoking when it came out and the other 3 were showing signs of overheating and they had black soot on the electrode/spring.

When I was running my Megasquirt last year, I ran these coils for 15,000kms on a 3ms Dwell cycle as per the reasons given by Joe Perez. The MS has options for cranking and running dwell. Cranking on the MS was 3.2ms or so.

On ECU Manager I only had the option for one dwell setting so I chose 3ms to be safe. I presumed the voltage calibration was the same as the MS, but obviously I was wrong. I am running a Haltech Spring ECU btw.

Here is a photo of the coil that stopped working, and one of the other three that were black and hot... but still working.

Melted/broken coil
Attachment 189389
Attachment 189390

One of the others that still worked... but was black. 15,000kms with the MS and they did not get black like this. The rubber boot on this one had very minimal melting to it as well.
Attachment 189391
Attachment 189392

These coils have approx 3800kms being run on the Haltech.


So before I replace them... I want to try to figure out what I can to do ensure it dosen't happen again. I was thinking to try a 2.5ms dwell cycle since some people have been running these Toyota COPS at 2.5ms without issue.

You didn't do that with 3ms of dwell. I ran a set at ~5.7ms of dwell (accidentally, missed a 190% multiplier in the AEM software) and in 4 months I popped two of them. No external damage, just no more spark.

If you're causing external damage, melting, etc. you've got a bigger problem than 0.5ms too much dwell.

They are wired into the car exactly as they were with the megasquirt. Same as everyone else has been doing. All they are getting from the ECU is the trigger. Other than the peice of hardware telling it how much dwell to use, nothing has changed from the megasquirt setup which gave me 15,000kms of trouble free use. Could plugs be the issue? I changed over to some Denso plugs... from using NGK's.

What do you think could be the issue?

FML. I just went and opened my map. Dwell was set to 2.5ms.

I am baffled as to why this happened.

I'd look to the software personally - does the Haltech software have an odd hidden multiplier? Who sold you the ECU?

Any chance you have the ability to scope the outputs to confirm that you're actually getting the recommended 2.5ms of dwell?

From my understanding it does not. LMS Efi (Ludwig motorsports) sold it to me and iirc I asked him back in feb about dwell and he said 2.5 or 3Ms would he fine.

Would a resistor type plug cause this? Holding in too much heat causing it to melt? I think I saw a bit of browning on the porcelain last time I pulled the plugs.

I dont have a scope, sorry.

On tr haltech forums for the ls1 coils the recommened dwell is 5ms which is the standard for ms too. So that makes Me think there is no multiplier.

Typing on my iPhone sorry if some stuff dosent make sense.

Coupld the boot not completely seating on the plug cause this? Arcing or something along those lines?

One other thing different since last time is I made a COP plate to mount the coils to. Before they were being pushed down from the top.


In any case, just picked myself up some LS2 coils. All the local wreckers wanted like $250 for a set of Toyota ones. I can't ebay it since I need the car running by tommorow. LS2 it is.