Car Stalls if release from gear with high RPM

[cabbageroll]

My 01 miata have a supercharge and my problem is while coming close to a stop if you suddenly switch from gear to neutral with about 2.5k+ RPM the car will stalls. But if you let it sit in gear and let some pressure out(Blow off valve) or just let it die down to 2, the car will idle perfectly. Any have experience this before with or without a supercharge/turbo? It's even worst after installing the inter-cooler. Before the inter-cooler, the car wouldn't die unless the RPM was maybe around 4k+. One thing I would add is that I haven't install the fuel management yet and it's currently running lean.

[— kung fu jesus —]

You have a leak somewhere in the intake charge, before the engine. If you are running a BOV, I would bet it is staying open, allowing unmetered air in. It may also be a coupler that has popped off, or the SC bypass valve is bad.

That all is going to be the least of your issues if you continue to run it lean like that, though. You will destroy the motor soon.

[— Agent☣Orange —]

If it's a typical SC system like the M45, it could very well be the bypass valve has gone bad but best to check for leaks or loose clamps first. Info on the SC?

[cabbageroll]

If it's a typical SC system like the M45, it could very well be the bypass valve has gone bad but best to check for leaks or loose clamps first. Info on the SC?

Yeah it's an m45. The car runs perfect if you drive for awhile and only really stalls when you start it up. I been having a choking issue on cold start/first start of the day before the supercharge. Changed plugs, wire, idle control valve, and last week crank sensor. Problem still there. Might check temp sensor. It usually give me a CEL that I'm running lean once a month and goes away few hours of drive. I may have to do a smoke test since I think there is leak and its just too small and can't detect untill underload.

[— kung fu jesus —]

What is the code?

[cabbageroll]

image.jpg

Here is the code.

I'll also add that when I got the car it already came with a CEL and the cold start/choke unless engine warms up. The code was misfire for one of the cylinder. After changing all the following item listed above the CEL went off and never came back. But the cold start problem was still there.

[— kung fu jesus —]

So, you are saying it is running lean, your CEL says otherwise.

Did you install the SC?

[cabbageroll]

Yeah my bad I got it confuse, I think I meant to say it was rich. Got that last CEL like a month ago. My brother was the one who installed it. I think everything else is in it except the boost control and fuel management. I'm sure installing the fuel management would make it run much much better. Didn't even know I had it until the supercharge was complete. Upgraded pulley so its much smaller too.

[— kung fu jesus —]

Yeah, so_much wrong going on with this, I don't know where to really tell you to start. I do, but I'm not sure it's going to help.

You are running 6-8psi of added boost with no fueling or compensation peripherals, pretty much like pulling the pin on a live grenade and juggling it with others while wearing oven mitts.

[cabbageroll]

Thanks for the heads up. Ill get right on it. Hope there is a guide somewhere.

[— Agent☣Orange —]

Cabbage, it is critical you install fuel management before you do anything else like intercooler, smaller nose pulley or even driving it around. What do you have, PowerCard? You have an intercooler too which is notorious for affecting idle. I want to tell you to read up on dual throttle body but I think getter that you understand the basics of forced induction first because you simply cannot force more air into a motor without more fuel.

[cabbageroll]

Cabbage, it is critical you install fuel management before you do anything else like intercooler, smaller nose pulley or even driving it around. What do you have, PowerCard? You have an intercooler too which is notorious for affecting idle. I want to tell you to read up on dual throttle body but I think getter that you understand the basics of forced induction first because you simply cannot force more air into a motor without more fuel.

Thanks for advice, just order the power card from here.

http://www.gomiata.com/mipotc2fuinc.html

Just hope my 1 month of driving didn't really damage much. Only put around 300 miles. After installing the supercharge I didn't drive at all but to test drive only since it was giving me idle issue.

I don't know much myself about dual throttle body but my brother went with that set up on my car. My brother was the one who install and I was only giving a brief overview of what he was doing. Dummy throttle on supercharge with the stock in the same place? Correct me if I'm wrong.

[— Agent☣Orange —]

That's the wrong card. You need the one for forced induction or a Megasquirt. In the meantime, you can either not drive the car or open the bypass so your SC doesn't kick in.

Dual TB eliminates the dummy and uses two actual TBs with butterfly valves and dual cable setup. It's really an elaborate setup for a first timer so I'm a little surprised there wasn't any fuel management in the box somewhere.

[cabbageroll]

I'm guessing the card I got from gomiata is for stock upgrade with cold air intake? Found the flyin miata voodoo box http://www.flyinmiata.com/index.php?...umber=07-16700, what I need?

[— Agent☣Orange —]

I guess. I wouldn't buy it if I'm just normally aspirated but it's a good way to spend money and play with buttons I suppose. I would buy a timing wheel instead and give myself a few more degrees of timing beyond stock.

The Voodoo box would be a good choice for your setup and FM is a good company but once you're at that level of expense, you're not far from a Megasquirt that would really allow you to fine tune everything. The beauty of the Voodoo is that if you don't want to mess with actual tuning, rather a quick solution, it would be perfect.