bogging out and shutting off :(

What's up guys, Im finally back now that I have my car from it being away for 2 years from being built. Hopefully I can make this clear enough without getting myself upset that my NA likes to bog and shutoff whenever it feels like it.

I have a 90 NA w/99 swap and S/C.

Ended up sending my car to a Miata shop to to get my whole motor built, forged internals, supercharger kit,MS2, trans, diff the whole enchilada. The car ran perfectly fine as it should for about 3 weeks (300 miles) and after that it started being bipolar, it began to shut off during idle when warming up, while driving especially when making left turns and when trying to turn it back on it'll backfire and just crank but won't turn over, bogging out while my wideband read low as 10.1 and high as 17.2. These are the issues that I've been dealing with, so I send the car back and was told the CAS took a shit and was replaced, 2 weeks later(50 miles) I'm back to the same issues. My mechanic said it can be 2 things defective fuel pump(Deatschwerks 255) or fuel pump harness female connector that the gaps might be too stretch out which is a common thing for 1.6 models so he says and also since I'm using the skunk2 throttle body its the reason it shuts off since has no idle control valve but other miata's with the same throttle body don't have that issue. Can that really be the problems I'm dealing with here? What are your suggestions/thoughts ??

btw Im running a MS2 and 91 pump

Just to eliminate a possible source of the problem, add another ground strap from the engine to the frame of the car. Also add a secondary ground to your MS2 and check your fuel pump ground. Make sure your battery cables are tight and the ground to the frame is clean.

It is cheap and easy to do.

Added to that, I was under the impression that the Skunk2 TB had a provision for the stock Miata IAC

Going to give that a try today and we'll report back if any differences

Quote:

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Originally Posted by MiataQuest

Just to eliminate a possible source of the problem, add another ground strap from the engine to the frame of the car. Also add a secondary ground to your MS2 and check your fuel pump ground. Make sure your battery cables are tight and the ground to the frame is clean.

It is cheap and easy to do.

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same here, if not might have to try a different shop

Quote:

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Originally Posted by HarryB

Added to that, I was under the impression that the Skunk2 TB had a provision for the stock Miata IAC

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A good shop will diagnose before just throwing parts at it.

It sounds electrical. I might datalog the MS, check the IAT sensor, reset and recalibrate the WBo@, assuming you are running one.

Did what others stated above and as well check the IAT and was fine as well reset the wideband and still the same thing.

Might have to talk with this other shop Tri Point Eng and go from there.

Quote:

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Originally Posted by kung fu jesus

A good shop will diagnose before just throwing parts at it.

It sounds electrical. I might datalog the MS, check the IAT sensor, reset and recalibrate the WBo@, assuming you are running one.

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Forgot to add that when I did a burnout 10 seconds later the motor hesitated as if it was choking and suddenly the car shuts down and it won't start literally 2-3 mins later without a problem if I leave it alone without cranking it over if not it'll just back fire and struggle trying to turn over.

Lol! Good luck.

Definitely datalog, it sounds like the MS itself might even be having problems. Some of your symptoms closely resemble when mine was having issues (especially the backfire but not starting)

^ that.

I had similar issues when the IAT started to flake and when my WBO2 started to foul.

You're kinda screwed if you can't do a lot of that yourself, you're going to need shops with experience in those aftermarket systems in that car.

The shutting off is concerning to me.

When the car shuts off, does everything power off or does the engine just stop. If it shuts off and the tac is slamming to 0 and everything just dies (not just engine stopping) this is baaad.
See if you can get it to shut off on its own while plugged in with TunerStudio etc and see if the MS disconnects.

If this specifically is happening you might be buying a new MS :(

Another thing that comes to mind is CAS