Car:

FD w/ 13b street port
Haltech PS1000 & harness
Haltech HP-4 & Haltech Bosch coils


This setup had an ignition issue out of the gate. It would start to misfire at 5500-6000RPM at only 15psi boost (71mm single turbo). The shop, supposedly well-known and reputable was never able to fix the issue. Aside from this, the car ran ok despite a pretty rough 'break-in tune'. It had a brand new motor so I figured I would attempt to address the misfire issue after the break-in. After less than 200 miles the car randomly died after about 20 minutes of run time. The following day the issue was traced back to a blown Ignition fuse within the fuse box that was part of the Haltech harness. There was a 20 amp fuse in a 15 amp slot.. I replaced the fuse with another 20 amp and the car fired up and ran fine. I was able to actually drive it twice, for about 15-20 minutes with no issue. It was particularly cool that day. A few weeks later, the summer heat had set it and I decided to take the car for a spin. The only change was I had put the stock hood back on; other hood was a vented CF. After about 15 minutes the fuse popped again. This time, I had a few extra fuses with me as a precaution... I popped a new fuse in, and as soon as I hit the key it popped. Tried another and same thing. Sat for a few minutes, tried again and it fired and ran for a second and then popped the fuse. After the car sat for about 90 minutes and cooled off, I popped another fuse in it and it started up and I was able to drive home. At this point, I am not driving the car on the open road anymore. I can start the car, let it idle, drive it up and down the driveway and so far have not been able to replicate the issue. I've let the car run for over 30 minutes but without any real load or heatsoak, it doesn't seem to do it. While it's running I've gone around the engine bay and moved/manipulated every possible wire, connector, etc.. to see if it was something physically shorting out to no avail. It is obviously heat-related. Any advice on where to go troubleshooting-wise would be greatly appreciated.


Thanks,

 

Direct spark setup? It's a coil issue if there pulling that much.

 

Yes, they are set up as direct fire with 5.000ms dwell. Would it make sense that a coil issue would be entirely heat-related?

 

Send me your map. chris@lms-efi.com

 

^Sent!

Also, I was mistaken -- dwell was set to 5.500ms (not 5.000 as indicated above).

 

I just wanted to bump this thread to ask if Chris was able to help you?

(I'm under the assumption that the coils are limited to about 4.5 Ms.So I'd think that 5.5 would be causing them to draw current and blow your fuse.

(PPSS: I'm not a tech guy,.just absorb/read a lot of tech stuff!)

 

Bump any solution here I have the same issue

 

Chris suggested I lower the coil dwell to 3.5ms, but I never got around to trying it. I was not confident that would resolve the issue since it previously ran fine at the original settings, which I believe were advised by Haltech to the shop that did the tune. I sold the car prior to resolving the issue. The new owner indicated the issue was a result of a short in the body harness.

FWIW, the Haltech data sheet indicates the coils can support up 10ms Direct Fire.

 

The only car I've used this combo on runs 30 psi and is shifted at 10.5k RPM and never gives us any issues. So, other than being expensive, there is nothing lacking in the coil and ignitor combination in my experience. There is also nothing that should be difficult or finicky about setting them up.

A word on dwell time. Dwell isn't some arbitrary value and saying a coil is good for x ms of dwell is only giving you some of the info you need at best. Can you dwell this coil 10 ms? Maybe. But certainly not at high revs. At 6k RPM you only have a 10 ms cycle. So, if you set dwell to 10 ms, you're at 100% dwell at 6k RPM and you melt coils. We charge the car I mentioned above at 3.5 ms and get good results. At 10.5k that works out to around 60% duty. Enough energy to do what we need it to do and a low enough dwell to not turn the coil to a liquid state.

 

Thanks for the detail. I didn’t mean to imply that 10ms dwell would ever be needed, or would otherwise be useful (in any application). Just that Haltech listed it as the max for a direct fire setup.

 

I didn't mean to imply you made anything up and I don't doubt their documentation says that. I just didn't want someone to read that and plug that number is and melt a coil.