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View Full Version : Ignition break-up at 5500-6200rpm



C-dubb
03-25-2014, 10:18 PM
So after I ditched the limiting 550cc set up and upgraded to 1000cc top feeds, the fuel problem is corrected but I'm having an ignition problem. At 15psi and 300whp the ignition cuts out bad right around 5500-6200 rpm. My tuner advised me that the car had a weak ignition system and that I needed to upgrade because it was causing ignition break up. So, I upgraded. MSD digital 6a, Blaster 3 coil, Magnacor 8.5mm plug wires. Problem is now, that there is still a terrible cutout. no change, at all.

http://www.celicatech.com/gallery/files/1/6/3/8/0/evo_583.jpg

There is also a lower rpm ignition break up at 2100-2300rpm at cruising speed it makes that car buck driving down the road.

Looking to see if anyone on here has any advice at all or has experienced a similar problem.

I have the AEM log if anyone wants to look at it I can email.

Funkycheeze
03-25-2014, 10:48 PM
AEM?

Try grounding the case of the ECM to the ground wires on the engine harness, and isolating the case from the frame of the car (use rubber). Worked for me!

You may also try a smaller spark plug gap.

T-spoon
03-26-2014, 06:45 AM
Yep, what plugs and gap are you currently running? Also sometimes reducing the coil dwell can help with ignition breakup/misfiring. I had similar issues with the supra. A small spark plug gap helped, but finally got rid of the issue by bringing the coil dwell down because they were getting a bit too warm and unhappy, apparently. Obviously a very different setup than yours, so YMMV

C-dubb
03-26-2014, 02:20 PM
Yep, what plugs and gap are you currently running? Also sometimes reducing the coil dwell can help with ignition breakup/misfiring. I had similar issues with the supra. A small spark plug gap helped, but finally got rid of the issue by bringing the coil dwell down because they were getting a bit too warm and unhappy, apparently. Obviously a very different setup than yours, so YMMV


AEM?

Try grounding the case of the ECM to the ground wires on the engine harness, and isolating the case from the frame of the car (use rubber). Worked for me!

You may also try a smaller spark plug gap.

Yes, AEM. I will try rhe grounding and seperating the housing from the chassis. That thought popped into my head but didn't think it would have a huge effect.

My plug gap with the stock ignition was at .016" ! I changed to a colder plug range and started now at .025" and the break up has improved a but but still very apparent. Thinking about bringing it down to .020" and see where I'm at.

How do you go about adjusting dwell time in the coil?

T-spoon
03-26-2014, 03:37 PM
Off the top of my head, I want to say it's under a coil/ignition tab near the end of the default row of tabs in the AEM software, but I'd have to look at it again (it's been several months since I was in there). On the dwell time graph there will be points throughout the RPM range. You can change each point by right clicking on it and entering a new value IIRC

C-dubb
03-26-2014, 04:26 PM
I'll take a look and see what I come up with
I didn't answer the question earlier about what plugs I'm running, NGK BKR7ES

MrWOT
03-26-2014, 08:45 PM
Is the ignition grounded straight to the battery and is the power wire at least 10ga? Also, try switching to a fine wire plug (ngk g-power). Last but not least, ditch the blaster and move to HVC-2. MSD p/n 8253.

C-dubb
03-26-2014, 09:22 PM
Ignition meaning the MSD 6a wiring? It's grounded to the chassis. Power wire is whatever came with the unit. Looks between 8-10. I want to exhaust all of my options outside of spending 250 more dollars on a new coil. I was thinking of changing to BKR8EIX plugs to see if they help.

Thanks for all the input guys, I will be taking a look at all of the things you mentioned to try and fix the problem. I'll let you know what I come up with. Hopefully I can get the issue resolved and get it back on the dyno soon for more tuning and testing.

C-dubb
03-30-2014, 05:37 AM
Grounded the EMS housing to the harness ground and added rubber grommets to the base of the casing. Gapped the plugs down to .025". Same issue, no change. another alltrac owner told me they were having a similar issue and it ended up being interference from the alternator and removed the alternator belt and ran the car that way to confirm. That's my next test.

Funkycheeze
03-31-2014, 08:10 PM
I'm out of ideas then. A complete solution to ignition problems would be to go coil on plug with a 4 channel CDI system that directly communicates with the EMS.