2004 MSM Stalling Problem
 

Hi guys,

I bought a 2004 MSM a few months ago. It was running OK initially, but started acting weird. I was wondering if you guys can give me some ideas of what might be causing the problem.
I don't know the technical terms, but I'll try to describe the symptoms the best I can.

While driving:
1. The RPM will drop and the engine will stall if I let off the gas and depress the clutch.
2. If I just let off the gas and coast in gear for a few seconds before depressing the clutch, the engine does not stall.
3. If I keep the RPM up and shift the engine does not stall.

When the car is just sitting in neutral, the engine does not stall after I rev it.

The following modifications have been made to the car:
1. AEM air intake
2. Larger injectors (I think 305cc)
3. Manual boost controller (set at 9.5 psi)
4. Flyin Miata downpipe, midpipe and exhaust
5. Larger aftermarket intercooler
6. Forge bypass valve
7. Bell Engineering throttle body inlet tube
8. New clutch and aluminum flywheel

I have taken the car to a mechanic and his initial thought was a leaky bypass valve. A new one from Flyin Miata was installed and the problem is improved. Now when I let off the gas and press the clutch the RPM will dip significantly and almost, but not stall.

Now the mechanic says the issue might be the stock ECU not being able to deal with the larger injectors: too much fuel causing the stalling when I let off the gas; letting the car coast in gear allows the extra fuel to burn off so no stalling in that situation.

What do you guys think? Any ideas?

Thank you.

sounds like he's right

Went to larger injectors with stock ECU? O.o
You're ECU doesn't know what to do now.

Your mechanic is right, the ECU can only compute so much and for what it's programmed for.

You may need to go back to stock injectors or look into trying to bypass that immobilizer to go standalone ECU.

IIRC the msm guys all seem to say 305's are borderline/OK to run on stock ecu. But no cars run exactly the same, so I bet yours is one of the ones that just doesn't like it.

I've never driven an MSM, but it seems that everyone who has agrees that the ECU sucks. It's probably time for a standalone, which will greatly improve the effects of the mods which are already done to it.

Either way I would turn down the boost and start reading before something goes boom. With the upgraded DP + Exhaust, you will likely see some overboost, which is probably what the PO put the 305cc injectors in there for. If the MSM ECU is like getting your leg blown off by a land mine (pretty accurate from what I've heard), putting 305cc injectors on it is the equivalent of strapping a band aid onto your fresh new stump of a leg.

Get a megasquirt. I promise you will not regret it. You will realize just how horribly the stock ecu holds back your MSM after you switch.

True

matting the go pedal, watching the boost shoot up to 10psi, and the car literally accelerating slower than a n/a miata, then at 5k LURCHING forward like a bottleneck was un-corked made me realize how bad it is lol.

Thanks for the replies guys.

It seems everyone is agreeing with the mechanic's diagnosis. That's great.

I'll have the stock injectors put back in, and turn down the manual boost control. Hopefully that will solve the problem. If it does, I'll think about putting in larger injectors when I'm ready to go with an aftermarket ECU.

Besides the Megasquirt, what do you guys think about the other ECUs like the Hydra, Xede or a reflash of the stock ECU that BEGi offers? I probably won't be doing much more modifications to the car other then suspension.

Thanks again!

Fuck a Hydra.

Xede is outdated.

Reflash is stupid money for not much value.

Megasquirt will massage your prostate.

MS is best for the buck, but if you're looking to stay at current levels and have OEM, well everything, then get the reflash. Its just way overpriced for what it is.

I would rather pay for someone to personally tune my car locally than to send the ECU out for tuning elsewhere. I'm sure Begi does a great job, but it won't be customized to your car because you can't mail them your car. For the same price, you can get a used MS2 and 2-3 hours of dyno time.

It really depends on what you want out of the car. Do you want to learn more about it and possibly tune it yourself, saving you money down the road if you ever change anything? Or would you rather ship your ECU off, install it, and never touch anything on the car again?

You better start looking up a way to bypass your immobilizer, by the way, I don't remember if anyone came up with a method .

My car runs and drives, but i do need to take the bulb out so it stop flashing at me.

You remove Ecu and put standalone = not going anywhere. Unless you've already removed it?

My car doesn't have the stock ECU, if that's what you're asking? Hasn't had it since 2006.

No ECU = no immobilizer. The immobilizer tells the ECU not to start the car. Since your standalone probably isn't set up to interface with the immobilizer, it just acts as though it isn't there.

you might have the "BOG" if try to give it some pedal and it just make noise out of the intake, But if it pulls ok it could be leaky bypass valve and just a bit to much fuel at idle/low speeds.

305's are fine on the stock MSM ECU it's really only hurting low speed and cruise fuel economy. Some MSM'S have very bad ECU's and there will be nothing you can do to get to run just right with no hesitation going into boost.
MY car responded great to a FM intake and O2 signal mod with almost no hesitation it almost pulled like it had a NA V6. However some cars had a bad hesitation going into boost and no easy mod will fix in that case you might as well just get a aftermarket ECU.

I have a HYDRA V2.5 if don't have tuning experience or the thought of a stand alone scares you don't even consider the HYDRA tuning the HYDRA is a gigantic pain in the ASS.

XEDE sucks can't change the rev limiter and it's a piggy back so that little evil box called the stock ECU is still in the car.

ReFlash not worth the money and again stock ECU retained the only plus here is the car may still pass emission testing.

AEM EMS-4 is now a option for the Miata and should work fine on the MSM. I have some experience with EMS-4 helped a friend tune a Scooby the AEM software is easy to use and the EMS-4 was not hard to get tuned.

Mega squirt best bang for the buck enough said and you will have loads of support on this forum.

All of that said the HYDRA on my car days are numbered after working with the EMS-4 and the mega squirt I built for my truck, I'm tired of the HYDRA it is such a ass pain to tune compared to almost any other good ECU on the market I even wonder why FM hasn't found a better ECU to use in there cars.

I thought you were the OP, My bad.

The immobilizer is separate from the ECU though isn't it?
I should know. I have my 04 MSM's harness in a box but I didn't wanna use it and much easier to just use my '99 harness. I forgot though, I may be wrong it tends to happen.

Unfortunately, i'm "blessed" with Hydra 2.5 on my MSM as well. FM tuned it for me July 2011. I haven't really driven the car since, since it runs like total asshole. I hesitate to blame FM, as i'm 90% sure it's just due to a total piece of shit product. But the fact that THE miata dealer for Hydra couldn't get the thing to run halfway correctly in a 2 hour session speaks volumes.

I'm giving it one more shot, then this shit is going away. Seriously horrible.

My immobilizer is constantly going off, i imagine it's probably bypassed, though. I was told this has something to do with why i have to use non-factory keys. (Those keys are in the glovebox, i dunno.) The light constantly flashes on the gauge cluster. I think the car just thinks it's always stolen.

I spent countless hours messing with the Hydra's tune trying to get the car to run just perfect. It runs good makes good power, but I'm going to get a EMS-4 or MS3 soon when I start my big power build.

Unless they changed something for the MSM that wasn't evident in my short google search, it's the same as the 01+. Which is that the ECU waits for a signal from the immobilizer to start. As long as whatever standalone you have isn't set up to work with the immobilizer (I know some do) it will just ignore that signal.

I assume you talked to Shane at Aim tuning? I would be surprised if he can't tune it or can't find someone who could, since lots of people also got them from FM. Especially since (I assume) the vast majority of the crowd who get hydra from FM aren't going to tune it themselves.

When you walk into Shane's shop, there's a big whiteboard on the backwall of the main shop area. (Not the dyno room.)

Item #1 on the "To Do List" is "Work Less."

I have to go to Aim this week and pick up my $275 Hydra wideband sensor that i had overnighted to the shop in Fall of 2011 for a scheduled tuning session that was pushed back and rescheduled.

Then pushed back and rescheduled again.

Then pushed back and not rescheduled.

Contact was made again in early 2012 with the intention of trying once again to schedule some tuning time. Was told that March/April would be great, and i'd be notified when the time came. No notification came.

I like Shane. He's a REALLY nice guy, and VERY smart. I'd trust him to tune the car in a heartbeat. From a business perspective, he could probably use some improvement. Or i need to build a Spec Miata car, since it seems like he has those coming in and out constantly. I don't see many street cars in his shop.


So really... a big portion of the issue i have with Hydra is that there's no readily available local support. There's two guys down in Louisville area that will attempt it. One has little to no experience with it, and hasn't done many Miatas, so pass. The other, i'm going to give a shot, and he even happens to have my Escort right now.

I even called 3-4 shops in CHICAGO, and they pretty much refused to talk to me further once i informed them what EMS was on the car.


There's really no value whatsoever in this product. None.

If i were to install an EMS with the idea that i'd tune it myself, i'd go Megasquirt, hands down. If i were to go with something i'd have a pro do, i'd contact the pro and find out what they're comfortable with, and go with that. You might find ONE guy in the country that would choose Hydra. Within 2 hours of my location, i'm looking at Haltech or AEM.

I'll be going Haltech if my dislike of Hydra reaches boiling point.

My car made 245whp on FM's dyno. As far as i can tell in the real world, that translates to about 160whp.

Maybe you're constantly driving it like you stole it and it knows??

That sucks, my car is in 230-250whp range based on the old ass dyno, but seriously my car makes ok power it would be great if I get the AFR's across the whole RPM and boost band where I want them the only way to that would be to spend hours on a load bearing dyne.

I drive it like a grandma because it's infuriating for me to drive it any other way. Lumpy-ass-shit powerband, no power, and pulls timing above 5500rpms like a 50 cent "adult entertainer" in Singapore pulls well.... you know.

Plus it's hard to concentrate on driving hard when you have to worry about the car stalling every time it comes to a stop and rev hang that can make upshifts take 3-4 seconds if you want to wait for the revs to drop enough for a semblance of matching.

Concealer where are you located, I could help your HYDRA tune some?

I have to be honest, I have no idea why it runs like that.
My stock MSM motor ran amazing with MS2 at 15psi on that shit turbo.

I'm in Indy. No worries... i should probably stop bitching because i'm unwilling at the moment to "help myself" and even figure out how to hook this bitch up to the laptop. (Ok i exaggerate, i can do that, but haven't done any logs at all, and i don't really plan to.)

I appreciate the offer. :)

But i need to replace the motor and diff mounts, and the exhaust manifold gasket. I've got someone who is going to tune it. If this solution doesn't work, then i need to sell the car, and quickly, as we're planning on taking this car on a 6000 mile trip in June/July. If the car doesn't run well, then it's getting replaced with an RX8, and quickly.

Probably because it's Megasquirt. I don't even have the stock turbo on this. It's not like it's running out of turbo up top.

Well I'll be in Cincinnati in apr-may if you want some help let me know it kinda sounds like some basic settings may wrong or not setup right. I would look at your tune but my PC laptop is being stored with my car at my Dad's house while I move.

PM me your number or something. A second set of eyes is never a bad thing, and even if the car is magically perfect by then, i could still put you up for a weekend or something if you feel like giving me a hand with some of the other pieces of shit i work on all the time.

I should actually be tuning a GRM $2013 Challenge car around that time.

Update on the car's stalling issue. Maybe someone with similar problem will find it useful.

After the stalling problem was improved with a new bypass valve, I did not have the stock injectors reinstalled, but asked the mechanic to do a few more things unrelated to the original issue.
The car wouldn't start when he tried to take it for a test drive. It turned out to be a dead fuel pump. The fuel pump was replaced and now the car runs fine. No stalling, no RPM dips :)

You put a Walboro 255 in there yes yes?

Unfortunately, it didn't dawn on me to upgrade the fuel pump :loser: The mechanic replaced to bad one with an OEM unit.