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-   MEGAsquirt (https://www.miataturbo.net/megasquirt-18/)
-   -   Intermittent Fuel/Spark Issue - Need Help (https://www.miataturbo.net/megasquirt-18/intermittent-fuel-spark-issue-need-help-78080/)

Matt Cramer 04-02-2014 09:47 AM

The new 3.3.1 code has made output test mode a lot easier - it now works the same way as the MS3:

Megasquirt MS3 Output Testing

We'll have to see what the test turns up and take it from there.

Ian 04-03-2014 04:00 PM

I am still on firmware v3.1.0

I am going to upgrade to see if that helps the situation. It's been something I've been considering anyway, I was just hesitant to potentially add to the issues I have.

Ian 04-04-2014 06:00 PM

Updated to 3.3.1

Went out for a spin but the problem is still there. I tried to stop the car and run the spark test, but nothing happened. Not sure what to be looking for while running the test. What means it is successful?

Chiburbian 04-04-2014 11:20 PM

Define nothing happened?

Dumb question, have you checked your spark plug gap?

Also, have we had you check your grounds? I have found that things get wonky sometimes if you don't have dedicated grounds running to the block itself.

Ian 04-05-2014 01:16 AM


Originally Posted by Chiburbian (Post 1118499)
Define nothing happened?

Dumb question, have you checked your spark plug gap?

Also, have we had you check your grounds? I have found that things get wonky sometimes if you don't have dedicated grounds running to the block itself.

There was no response when running the test so I shut it off.

New BKR7E-11 plugs were installed a couple weeks ago and gapped to .030.

I have not checked the grounds. Will look into that tomorrow

Chiburbian 04-05-2014 03:18 AM

Specifically, check the grounds on the ECU to the block as well as the injectors to ground.

How are your injectors attached to your harness? Check for any places where any heat shrink tube might have chafed through and you may be shorting your injectors.

Ian 04-08-2014 04:10 PM


Originally Posted by Chiburbian (Post 1118528)
Specifically, check the grounds on the ECU to the block as well as the injectors to ground.

How are your injectors attached to your harness? Check for any places where any heat shrink tube might have chafed through and you may be shorting your injectors.

Grounds are solid. No visible issues with wiring to/from injectors. I am using plug-and-play adapters from FIC that were zip-tied to the stock harness so they can't come loose. Checked those as well and everything looks good.

Taylor ThunderVolt wires have about 8k or less on them and look to be in great condition. Could be related though, so I'll try swapping them out for my old set of NGK's in the next couple days when I get some free time.

I'm leaning toward the coil pack at this point. LSx coils may be in my very near future.

Matt Cramer 04-09-2014 09:19 AM


Originally Posted by Ian (Post 1118511)
There was no response when running the test so I shut it off.

If it wasn't sparking (you might want to use one of the inline spark tester tools to make it easy), I'd suspect the coil pack is having problems that cause it to shut down when it heats up.

Chiburbian 04-09-2014 07:04 PM

i'd borrow a coil pack (if that's possible) before I spend the money on LS coils. Nothing wrong with them but no point throwing money at a problem.

How long does the car need to run before it starts having this problem? Could your dwell be set too high maybe?

Ian 04-09-2014 07:47 PM


Originally Posted by Chiburbian (Post 1120073)
i'd borrow a coil pack (if that's possible) before I spend the money on LS coils. Nothing wrong with them but no point throwing money at a problem.

How long does the car need to run before it starts having this problem? Could your dwell be set too high maybe?

Unfortunately, I don't know anyone with spares near me test the coil pack. I look at the upgrade as eliminating a weak link that will fail inevitably. Car was boosted before and will likely be again so it makes sense to do it now instead of later.

The issue is intermittent so it comes and goes at random. The problem I have with tracing this back to MS settings like dwell is that I never had a single issue before this. It started out of nowhere and I'm running the same settings Braineack supplied with my DIYPNP that worked for close to a year without issue. I can try to play with it, but I'd be worried I would do more harm than good.

Ian 04-10-2014 04:47 PM

Swapped in my backup set of NGK wires and took it out for a test drive. Seemed to run well for 40 minutes or so until all of a sudden after a WOT onramp, the car bucked heavily and started puking heavy whitish smoke (oil). I limped the car back home, check oil level and it's completely dry. There is a misting of oil from the top of the valve cover and pools near the exhaust manifold and the drivers side of the block looks pretty covered. I couldn't see any holes in the block, but at a minimum my rings are shot.

Now shopping for long blocks. GOOD TIMES... :beer: :beer: :beer:

Chiburbian 04-11-2014 01:04 PM

Fuuuuuuuuuuck

rndmheroxx 04-11-2014 03:24 PM

Carnage pics or it didn't happen!

Ian 05-09-2014 10:29 AM

Repeated dry compression numbers confirmed what I assumed:

1: 190
2: 115
3: 190
4: 190

Gt2560rMiata 05-11-2014 02:23 AM

What were your afrs at wot before you started having all these problems?

Ian 05-11-2014 01:53 PM


Originally Posted by Gt2560rMiata (Post 1130013)
What were your afrs at wot before you started having all these problems?

12.6:1 at torque peak raising to 13:1 at 7200 rpm cut. Tune is attached on first post for specifics. AFR targets were inline with actual AFRs.

The motor had 170k+, a short stint of boost, and a lot of track days. It served me well.


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