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-   Prefabbed Turbo Kits (https://www.miataturbo.net/prefabbed-turbo-kits-3/)
-   -   FM Stage 1 Idle Droop Issues (https://www.miataturbo.net/prefabbed-turbo-kits-3/fm-stage-1-idle-droop-issues-104640/)

jon.wright.lbc 02-09-2021 05:33 PM

FM Stage 1 Idle Droop Issues
 
Hey Guys, I just installed my FM stage 1 turbo kit. I followed the instructions very carefully, The car seems to be driving nice and smooth, fires up with out any issues, but if I rev it in neutral, or pull it out of gear and coast to a stop, it will stall. I have adjusted the Idle control screw on the top of the TB. I sprayed some carb cleaner around all the fittings and hoses looking for vacuum leaks, but nothing jumped out at me. Any other suggestions as to what could be causing this problem?
https://us-east-2.protection.sophos.com?d=youtu.be&u=aHR0cHM6Ly95b 3V0dS5iZS8tXzRnX3ZSaEVqYw==&i=NWY0NDMyYmY2YzM4YTcw ZWI0NDI4ZjJj&t=THRBeFNVektsaWROYzVRZytpdS9VaE5QREd 2MDJKT3BSaTI5cTJ6NlJDVT0=&h=c26ecf87699346a69d8c19 781301409a



Black&Tan00 02-13-2021 04:59 PM

Recent install of stage 1 on NB1. I'm having the same issue. Per FM tech support, backing out the idle control screw is supposed to be the fix. It may take a lot of turns and you might get an occasional high idle code. Not sure, but might be a weakness of the VooDoo instead of full stand alone.

...and, you won't much support on this site. Stand alone or nothing. I'm likely to go to stand alone in the future, but i have emissions testing to contend with.

emilio700 04-03-2021 10:55 AM

We just installed one of these kits on an NB2 shop car. Same problem. Not only does raising the idle not correct the problem, it's a bit of a Band-Aid. We're going to dive in and see if there is a proper fix.

I think the place to start is to monitor all the relevant sensor signals in real time with a scan tool. We have a stock NB2 as well so we can compare the sensor data logs from both cars and try to glean what the OEM ECU control algorithm is and why it's not catching it.

If we figure out a fix we will post it here but start a new thread as well. My guess is there are a whole bunch of people with this kit that had the exact same problem.

jon.wright.lbc 04-03-2021 11:01 AM

So I did confirm I had a decent boost/vacuum leak from the plenum gasket. However I have since installed the megasquirt and a new flat top intake and a bunch of other new parts in preparation of taking it to the tuner.. so I don’t know if that was really the problem, the car appeared to be holding about 5 psi.. but with noticeable leaking around the back and sides of the intake manifold. Do a proper leak down test first and let me know how it goes

emilio700 04-03-2021 12:14 PM


Originally Posted by jon.wright.lbc (Post 1596877)
So I did confirm I had a decent boost/vacuum leak from the plenum gasket. However I have since installed the megasquirt and a new flat top intake and a bunch of other new parts in preparation of taking it to the tuner.. so I don’t know if that was really the problem, the car appeared to be holding about 5 psi.. but with noticeable leaking around the back and sides of the intake manifold. Do a proper leak down test first and let me know how it goes

Vacuum leaks and standalone ECU; different type of solution. Our NB2 is 100% stock other than a high flow cat/exhaust and the FM1 kit.

If your tuner understands the MS software well, they should be able to correct the idle droop. Good luck with it.

fwman1 04-03-2021 12:51 PM

In the original video the MAF is still in place. Before going MS3 I ran my NB1 on stock ecu and AEM FIC6 piggyback with both M45 supercharger and FM1 turbo kit. I had some minor issues related to the air intake track as the MAF would react to flow changes when the throttle plate closed. You might want to test venting BOV to atmosphere (plugging that hole in the elbow) to see if it has any effect on the behavior.
Just an idea to try.

insanic 04-07-2021 05:38 PM

I have a NB2 with the FM Turbo kit and the exact same issue. I heard somewhere that FM stated that it was a combination of the retarded timing from the adjustable trigger wheel and the voodoo box. If you guys found a solution that would be amazing, I know a couple of other NB2 owners with the same issue as well.

insanic 05-19-2021 02:03 PM


Originally Posted by emilio700 (Post 1596875)
We just installed one of these kits on an NB2 shop car. Same problem. Not only does raising the idle not correct the problem, it's a bit of a Band-Aid. We're going to dive in and see if there is a proper fix.

I think the place to start is to monitor all the relevant sensor signals in real time with a scan tool. We have a stock NB2 as well so we can compare the sensor data logs from both cars and try to glean what the OEM ECU control algorithm is and why it's not catching it.

If we figure out a fix we will post it here but start a new thread as well. My guess is there are a whole bunch of people with this kit that had the exact same problem.

Have you guys been able to make any progress in identifying the cause of idle droop?

emilio700 05-19-2021 02:41 PM


Originally Posted by insanic (Post 1600451)
Have you guys been able to make any progress in identifying the cause of idle droop?

Nope. I'm twisting John's arm to datalog all the sensors during an idle droop vs our bone stock NB2. My notion is that a signal modifier on an arduino board might be all it needs. Maybe not. Need the datalogs first.
He's sorta over it, raises the idle to one million and just doesn't drive it much because of the driveability thing there doesn't seem to be a fix for.

If anyone wants to share a 10s datalog of the droop/stall here, I can force John (nothin but love..) to get one from our stock NB2 and see if we can identify something.

insanic 05-19-2021 02:46 PM

Once my car clears customs, I can try to datalog it, unfortunately I only have a bluetooth odb2 reader which... isn't exactly super responsive, but I'll see if I can get a usb cable to log everything. As far as driving it, I find that coasting when I know I'm going to stop soon and then just shifting to neutral helps prevent the drooping so at least I can drive it. It's mostly frustrating when you have to stop and go a lot.

Eoj 07-01-2021 06:22 PM

FM Stage 1, NB 1
 
Have the same issue and chased it around. I decided to take it to a guy near me who knows much more than I do about these cars.

He couldn’t figure it out and mentioned to me that the car could have a lightweight flywheel (I have no way of knowing this as I purchased the car with the kit installed already).

I tried looking for vacuum/boost leaks, cleaned out my throttle body, intake manifold, etc. no fix so far. Especially the throttle to neutral idle dip. The car will almost die and then figure itself out after maybe 10 seconds.

ehlk 08-28-2023 02:03 PM


Originally Posted by emilio700 (Post 1596875)
We just installed one of these kits on an NB2 shop car. Same problem. Not only does raising the idle not correct the problem, it's a bit of a Band-Aid. We're going to dive in and see if there is a proper fix.

I think the place to start is to monitor all the relevant sensor signals in real time with a scan tool. We have a stock NB2 as well so we can compare the sensor data logs from both cars and try to glean what the OEM ECU control algorithm is and why it's not catching it.

If we figure out a fix we will post it here but start a new thread as well. My guess is there are a whole bunch of people with this kit that had the exact same problem.

Running into similar issue on my 2000 nb - have you guys had any luck finding a long term solution?

emilio700 08-28-2023 02:06 PM


Originally Posted by ehlk (Post 1640707)
Running into similar issue on my 2000 nb - have you guys had any luck finding a long term solution?

Sorry, no. John sold the kit. I wanted to investigate, he wanted to move on.


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