Well i had my buddy come out and tune the car. It ran beautifully! The next day i was driving to work the car started bucking and my wideband would go from my normal cruising AFRs to about 17-18:1 afrs. I thought maybe it was raw fuel causing the reading so i pulled the plugs to visually inspect them. Cylinder 1 and 4 were white (cyl 4 was definitely leaner then 1) and cylinder 2 and 3 looked about normal. When i drive the car it seems like it goes rich then lean causing it to break up itermittently. When the car does this it wont start without me flooring the gas pedal (even after flood clear) it also will not idle. Idle afr's are around 18:1 when it acts up. The next day i go for a drive..... it runs fine, just like it did when he tuned it. My tuner thinks it is something mechanical, I on the other hand think it is something to do with the MS. I am completely lost! I did get 2 logs of when it was acting up, one highway and one on my street. If someone is interested in looking at my msq and logs I will gladly email it to them since I have no idea how to post them. Any help would be greatly appreciated!

BTW I am running ms1 v3.0 with spark. I am running igbts instead of vb921's, 850cc low impedance fuel injectors

Running closed-loop? If so, what type WB?

/>

'95 GS w/ t3/t4b
FMIC, diy piping & RFL BOV
MS2-Extra Fuel&Spark
50 lb/hr Holley injectors w/ 1:1 RRFPR
JE 8.8:1 dish w/ Hastings Rings
Eagle Rods w/ ARP bolts
ARP Head studs
Mild port/polish head
3" custom DP/cat section, 3" PIT catback
dual MBC - 12 psi / 20psi

closed loop limit set to 95kpa, aem 0-5v linear output wb.

well we disabled the ego correction and the open/closed loop and i havent had the issue since.

I was kinda wonderin, because I have the AEM UEGO and it's a piece of junk. If you have the same one I have, the output mode changes at random times, switching it from 0-5V output to MS to 0-1V, effectively trickin MS into thinking it's runnin super rich and MS leans it way out to correct it. My voltage output, even in the correct mode, still doesn't match AFR between the gauge and MS, as 14.7 reading on the gauge will have to be input around 15.8 or so on me AFR tables to keep it correct. Just some thought.

/>

'95 GS w/ t3/t4b
FMIC, diy piping & RFL BOV
MS2-Extra Fuel&Spark
50 lb/hr Holley injectors w/ 1:1 RRFPR
JE 8.8:1 dish w/ Hastings Rings
Eagle Rods w/ ARP bolts
ARP Head studs
Mild port/polish head
3" custom DP/cat section, 3" PIT catback
dual MBC - 12 psi / 20psi

that definitely makes sense. My wideband guage and megatune match numbers pretty damn good. I knew i should have bought an lc 1

Another trick to try - is to adjust the closed-loop behavior of how wide of a range and the rate it updates the "fuel trims". How often the MS is allowed to adjust your injector pulsewidth, the percentage step, and the absolute limit, strongly affects driveability and fuel economy in closed-loop conditions. When I had my MS 5+ years ago I eventually got it down to +/- 5% at 1% steps. I'm not saying that's the exact value that you should be trying to hit; every car is different. But, under ideal conditions, your VE table should be so perfect that you shouldn't be needing any kind of EGO correction. That is, however, virtually impossible to achieve, but it's a good place to shoot for.

Bottom line - the VE table is where it's at, EGO correction is for fine tuning.

2016 WRX STi Limited (current)
2001 A4 1.8tqms (donated)
1991 GVR4 #1933 (sold)
old.dsmregistry.com/detail.php?carid=218 (dismantled)

well I finally broke the motor in and decided to go for some WOT street tuning. Got the car running great on 10 psi creeping to approximately 14. After about an 1 hour and a half of street tuning (WOT, partial throttle and dd conditions) the car would run like a tugboat/subaru hybrid. The AFR's would go very lean...about 18-19 afrs. The car basically runs exactly like it did when I had vb921s and they overheated. I am currently running the IGBTs that rs-autosport offers. I am running with EGO correction disabled and open/closed loop off). Do you guys think I could have overheated the IGBTs? I am running 7.0 cranking dwell and 5.0 running. I checked Fuel pressure and its fine. The plugs look lean. This car is killing me!

Well my tuner thinks it is the flyback board. According to what I have been reading the symptoms match. I might just run resistors instead.

V3.0 board does not have a flyback board (that is reserved for V2.2). V3.0 does have a flyback circuit for PWM control of peak & hold injectors. If you had the wrong settings for the injectors, you could have overheated components in the flyback circuit or injectors. It might be wise to run through my old MSQ. Click "save target as".

http://www.2gnt.com/www/corbin/MSIExtra_trial.msq

At that time, I was running MSI, V3.0 board, 029Q code, LC-1 WB, VB921s driving 4G63 transistor, and PWM control of 780 cc P&H injectors. The car ran well with those settings up to 15 psi. I eventually switched to the MSII and opened up a new world of problems that I am still working through. If you want, E-mail your MSQ (use the link by my profile)

Corbin
'95 ESI-T

Now with more power and fewer leaks



Humble servant of the Wiki

When i was running vb921's I never used a transistor. I apologize for the misprint, my tuner thinks it is that circuit. we have been doing some reading on flyback failure and most of the symptoms match. Corbin I PM'd you about your email. I will send you my msq as soon as you reply. thank you for the help and time!

Sorry, it has been such a long road. I started with two internal VB921 transistors on the V3.0 board, removed them to use the external 4G63 module, and now am using two internal Fairchild transistors on a daughterboard. The MSQ I gave a link to was only using the external 4G63 module. You should have an E-mail from me.

Corbin
'95 ESI-T

Now with more power and fewer leaks



Humble servant of the Wiki

well i found a couple issues that i fixed. The first one was a poor connection in my power supply for my fuel injectors...i soldered that. I made some changes in megatune according to the megamanual and wired inline resistors for the injectors since i thought i was experiencing flyback failure. The map needed some adjustments due to the resistors but my buddy got it back to normal in no time. I experienced a random lean spot while driving for about 10 seconds then it went back to normal. We drove around for about 1 hour doing some mixed driving and it was back! I noticed that when i rev the car it kind of clears up. We have ego correction and open loop/closed loop disabled for trouble shooting reasons. While the car was driving normally i reccomended enabling ego to see if thats what causing it, we enable ego and about 5 min into it is running lean as crap (18-19 afr). We disable ego correction and it is still doing.... I cut the car off to reset MS after disabling ego and the car is back to normal for a small period of time. If I am anything over 1/2 throttle and the car is running like crap it will intermittently run normal to rich instead of lean. Im lost and frustration is getting the best of me.

Well rs-autosport doesn't seem to have the courtesy to reply to my emails, Paul over at Symtech labs stepped up to the plate and is taking a look at my ms for me. Big thanks to symtech anfd 2 thums down for rs-autosport.

paul got done with testing on my ms and said all is well. I dont know what else would cause this issue with the car. I am gonna start with the fuel pump because it is pretty loud. I am also gonna swap out the coil as well.

well i guess we fixed it. I told my buddy to go man handle the harness while the engine was running and we found a spot that made the car run like ass if pressure was applied to it. I took the harness apart expecting to find an open wire or poor solder but there wasnt a solder joint even close to that area. The wires were for the injectors and coil. Im not sure if this makes any sense so i am putting my flame suit on. I had all my coil and injector wires ran together in the same loom. I isolated the coil and injector power supply wires from the remaining wires and voila. Im guessing if it was some kind of electrical interference. All i know is that there was no breaks, solder points or exposed wires. I have been daily driving the car for the past 2 weeks with no issues.

well, I thought i fixed it! The problem came back once i started going wot again.... good news is i fixed it this time! I changed out the msd coil and switched to a stock flat pin coil and voila! after this i ran into reset issues... I followed wickedesi's capacitor advice and the car runs like a dream. I tried everything from hi z injectors, rewiring the harness. Let this be a lesson to all! Random lean condition could possibly be a coil! sticky this!

Captain Caveman

96 RS Turbo 11.414 @ 119.62 MSNS, Crower 2 NA cams, BW366, 10.5 comp, UDP, 60mm TB, W/A intercooler, 3.55 tranny 567.9whp 430tq
97 RS NA 13.188 @ 103.87 MSnS powered 12.5 comp, Crower 3's and 219.4whp with 175tq
98 RS DD 12.5 comp on stock ECU, LTH, Crower 2's, Koni, GC, Hypercoil, DG hats
99 OZ 5sp Stocker 15.856 @ 85.97
99 GS stocker auto 17.7@77mph!

wiki home page:http://www.2gnt.com/index.php?d=bullettdsm

Careful. Resetting is a real good indication your getting detonation. My MS will reset when it picks up a good detonation event or serious misfire.

I have never added a capacitor and I have never had resetting issues even with a v3.0 board.

you saw my sissy timing map... I highly doubt it was detonating. I pulled the plugs and there are no signs of detonation. I have been daily driving the car and beating the crap out of it for the last month or so and all is well. What are you guys running for knock reading? Knocksense doesnt really seem to be worth it from what i have been reading.

There's an interesting thread going on in the Neons.org forums about detecting knock:

http://forums.neons.org/viewtopic.php?f=60&t=350808

So far there aren't many good options for detecting knock through Megasquirt, but hopefully that will change soon.

-----------------------------------------

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systems, accessories & more!

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Knock sensor info? Where? Edit your post, the one you posted seemed to go on forever.

-Rafiel