Chokes off after shifting under boost

[hellssephiroth]

Hey guys, just switched to a chrome ecu but I did a few other mods as well. I switched to a blow through setup open atmosphere with gm maf, installed pre cat eliminators, and M2 exhaust. It runs great on and off it seems. The other day it was choking off I forgot to tighten a hose clamp, fair enough whoops. Ran great for a few days and now I run to go get some pizza and it seems the car in general is running really rich. Idling at 13 where it was 15-16 and after I shift it runs so rich when I let off the gas it just chokes off.

I figured it was just another hose that blew off but I pulled it all apart and re assembled it and I am still having issues.....

Any ideas? I am still running stock turbos and injectors at the moment if it matters.

[hellssephiroth]

Well i ordered new O2 sensors..... maybe i will get lucky and that is my problem.

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[Greg E]

I kinda doubt its the sensors. Try taking away fuel in the areas you're running rich.

What are your long term fuel trims doing?

[hellssephiroth]

Everything seems all over the place....? My afr is bouncing from under 10 when it chokes off to sometimes 18 all without even hitting boost. Cruising is the only time its decent around 14. I havent touched the fuel maps at all yet.

The only thing i messed with so far in the ecu is turning off the stuff for 1st gen and for vacuum reduction,egr delete, etc. I also messed with the rev limiters thats about it. I can see if i can mess with the maps a bit after work. I suppose i could have turned something off i shouldn't have. I will try the stock flash and see if it doea it.


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[Greg E]

The ECU doesn't care about your wideband. It goes off the narrowbands and all its doing is trying to make them cycle. In fact, the only time you should even be looking at the wideband is during heavy acceleration. Examining what the narrowbands are reporting to the ECU and what the ECU is doing with that information will help clue you into the real issue.

Replacing a sensor because its not reporting what you want to see isn't going to solve the issue. The sensor is just a messenger. :)

[hellssephiroth]

ok here is pics of a log, I did't beat it really just took a little cruise around the block getting a little boost.

Narrow bands
http://i446.photobucket.com/albums/qq185/Hellssephiroth/narrowbands_zps2f9d58e6.jpg (http://s446.photobucket.com/user/Hellssephiroth/media/narrowbands_zps2f9d58e6.jpg.html)

TPS and RPM
http://i446.photobucket.com/albums/qq185/Hellssephiroth/rpmtps_zpse1d84bd1.jpg (http://s446.photobucket.com/user/Hellssephiroth/media/rpmtps_zpse1d84bd1.jpg.html)

Wideband
http://i446.photobucket.com/albums/qq185/Hellssephiroth/wideband_zps24a6a686.jpg (http://s446.photobucket.com/user/Hellssephiroth/media/wideband_zps24a6a686.jpg.html)

[Greg E]

Looks like there was quite an earth quake in your area!

[hellssephiroth]

Fuel trims aren't showing up at all in evoscan? they are all zeros and one is -25. The pics above were with the stock flash back on it except what i had to turn off for 1g stuff in peripheries 2. It still seemed to do it when i hit 3rd gear and left off. I noticed when I left off in 3rd my bov is acting really wierd. It blew off like 5 times? Never did that before...... It is a Turboxs RFL if it matters. I really want to try out a synapse perhaps I will order one this weekend.

[Greg E]

You're not using my evoscan file. :p

Edit: saw you edited your post. The readings you were describing were items omitted from my file. That's why I assumed you were using the wrong file.

[hellssephiroth]

lol huh? I have EFI 3000gt selected? Is that the wrong one?

[hellssephiroth]

http://i446.photobucket.com/albums/qq185/Hellssephiroth/20130513_150851_zps05138af1.jpg (http://s446.photobucket.com/user/Hellssephiroth/media/20130513_150851_zps05138af1.jpg.html)

[dbest671]

Stupid question, but have you pressure tested? I saw where you said you pulled it apart and reassembled... but read nothing about an actual pressure test.

[Greg E]

Well that looks like my file (with a few extras added in)

Did you disable any of the periphery 0 bits?

[Greg E]

Oh you edited your one post.

Set your BOV to the tightest setting possible.

[hellssephiroth]

I suppose I should probably do that :P I need to run to take my wife to work quick and I'll set up the pressure test.

[hellssephiroth]

It is at the tightest as far as I can tell. I don't really see any way to make adjustments to it?

[Greg E]

I'll bet you a taco all your issues go away if you swapped the stock BOV back in. :)

(And set it up closed loop like stock)

[dbest671]

I'll bet you a taco all your issues go away if you swapped the stock BOV back in. :)

(And set it up closed loop like stock)

Another stupid question on my part Greg... but how do you go back to a recirculating BOV on blow through set-up? I'm trying to learn as much as possible.

Reading this thread... Blow through setup help - 3000GT/Stealth International Message Center (http://www.3si.org/forum/f35/blow-through-setup-help-507284/) (sorry to link you to the other site).

I might be retarded... I assumed you deleted the "bubble" on blow throw.

[hellssephiroth]

yep its all gone I am running dejon pipes

[Greg E]

Well, I still bet a taco the problem is the BOV.

[hellssephiroth]

Well i found a plenum boost leak..... ill throw in new gaskets quick

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[hellssephiroth]

Ok, so I changed the gaskets. I don't feel or hear any air anymore from anywhere. Now for the first time ever I am seeing blue smoke from the exhaust *shrug*

Here is new log pics

http://i446.photobucket.com/albums/qq185/Hellssephiroth/20130513_192020_zps4794d316.jpg (http://s446.photobucket.com/user/Hellssephiroth/media/20130513_192020_zps4794d316.jpg.html)

http://i446.photobucket.com/albums/qq185/Hellssephiroth/20130513_192050_zps77b909a9.jpg (http://s446.photobucket.com/user/Hellssephiroth/media/20130513_192050_zps77b909a9.jpg.html)

http://i446.photobucket.com/albums/qq185/Hellssephiroth/20130513_192102_zps433f06ae.jpg (http://s446.photobucket.com/user/Hellssephiroth/media/20130513_192102_zps433f06ae.jpg.html)

[hellssephiroth]

Its going in tomorrow for a new timing belt and water pump.... hopefully I have something figured out before this weekend so I can make it to the Minnesota meet :(

[hellssephiroth]

Oh just to throw it in there I was using this BOV since 2005 lol on my eclipse then the 3s. I had it releasing to the atmosphere the whole time I owned the car even with the stock maf, I know it runs rich, but I never had this much trouble. I suppose I could just order the synapse..... will have to wait until after the meet though.

[hellssephiroth]

Oh I didn't see you asked about periphery 0, didn't touch anything.

[hellssephiroth]

Ok so back from getting the timing belt changed I went over it and redid all the gaskets I could easily get to. I am golden on the leak department now. Still does it, actually worse now :( I am suppose to have my maf translator on 8 and 2 yet correct? It really runs like crap if I zero it all out completely so I put it back.

Also was I supposed to change anything in chrome seeing as how I have a 3.5 gm maf installed? I was wondering about Maf size and such. Just trying to narrow it down a little. I haven't touched any of my fuel maps yet, I kind of figured It would run a little smoother being the injectors and turbos were still stock? One thing I notice as well if it means anything is when I rev it stationary or shift my rpms drop down to like 300ish and then bounce back up [if it doesn't choke off].

Thanks for the help so far.

[Street_Chally73]

As long as you can limp it to the meet, I'd say that Greg & a few other of the very savvy tuners will be able to figure out what's going on. I know Greg impressed Joe within a very short amount of time on his '99. ;)


Sent from the garage

[hellssephiroth]

Oh it will be there no matter what lol. Look for the guy with the green mohawk if you think you can help lol

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[Street_Chally73]

LOL, my 'tuning' skills consist of testing a couple things then throwing some money at it until it works properly... :suspect: EFI tuning to me is a science that I have yet to master.

But seriously, I'd bet someone at the meet will be able to figure out what's going on & either be able to fix it on-the-spot or give you specific solutions to properly fix it later.


Sent from the garage

[hellssephiroth]

YES! Replaced the rear O2 sensor and it runs like a brand new car :)

[hellssephiroth]

Put on 400 miles this weekend without a hickup.

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[hellssephiroth]

Blah so I installed a new fmic.... doing it again, leak tested checked out good except i notice biss screw has a slight leak, ill put a new o ring on it tomorrow. Ugh this is annoying me. Well I ordered a new BOV whenever that comes, its my final guess. If it doesn't fix it how much do you charge for a throttle body fixer upper April? Or should I look into getting an aftermarket one? I plan on making the switch to e85 as soon as I get it running properly on normal gas.

[dbest671]

unless you want to upgrade plenums (or port yours to the extreme) in the process, there is no real "upgrade" throttle body IMO.

Standard rebuild is $120 + your core or core charge. And I don't have any 91/92 TB right now, and ordering rebuilds parts tomorrow. Have the shaft seals, but nothing else at the moment.

[hellssephiroth]

I dont mind upgrading the plenum. If something works better im all for it.

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[hellssephiroth]

I wouldnt mind not having to remove the throttle body everytime i pull my plenum off either.....

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[dbest671]

Why do you have to remove the TB every time you take off the plenum? I leave mine on LOL, and just take out the four bolts attaching it to the plenum, and loosen the one on the backside.

I can't comment if "it works better", the larger plenum and TB combo. But I've seen 500+ hp guys using stock plenum and TB... plus you are talking probably over $1K to get a decent set-up.

[hellssephiroth]

Ya true probably better put to good use on new turbos. I just wish i knew if it was even tb related :(

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[hellssephiroth]

Ugh its getting to the point where I might just have to trailer it somewhere that knows what a 3000 is to tune it..... and then offer them the best of luck. I wouldn't think with stock injectors and turbos yet it would need to be fully tuned but its my last idea ..... I put a new o ring on the biss and it stopped the leak but didn't help. Whatever it can just sit here i guess until i throw a new engine in it, then i will deal with it. The way it runs now I feel like it will just blow it up.

[hellssephiroth]

What are the chances my piping is just too big for the turbos..... I know probably not but im running a lot of ideas in my head. I wish my bov would come.

it just smells so rich its nauseating i dont get it.

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[hellssephiroth]

If anyone has time to look at me logs that would be awesome. The zip labled "IDLE" is with the stock flash minus the stuff turned off for a vac reduction/first gen. The "3000gt logs" one is with the flash I was running.

[hellssephiroth]

Installed new BOV. still the same problem. Now I see I am starting to smoke blue never did that before... i hope its just because im running so rich. Do you think it may be the throttle body or should I keep looking elsewhere?

[hellssephiroth]

Cleaning up the tb right now ill throw it on tomorrow and see if it helps

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[hellssephiroth]

Threw the throttle body back on, now with my biss screw all the way in the lowest i can get my rpms is 1500 :( did i put it back together wrong? I took pictures and it all looks right :(

[dbest671]

Did you take it apart or just clean it? Also make sure you have the TB gasket on correctly, the little tab should be closest to the firewall.

[hellssephiroth]

I ripped it all apart and steam cleaned it real good.

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[hellssephiroth]

I also pulled out the multimeter and checked that the idle switch was working and from what i can tell it is I dont know why its not showing up in evoscan though.... hmm

[dbest671]

Like take the throttle plate out? If you removed the throttle plate, you need to reset everything from the SAS to the TPS. I'm guessing the throttle plate isn't closing as far as it should because you should have a pretty low idle with the BISS all the way in. Also, don't forget to put the .65mm feeler gauge on the throttle lever (where the throttle cable attaches to) when you set the TPS. And loosen up your throttle cable on the plenum, it may need to be readjusted. Did you replace the shaft seals while you had it apart? If not, most likely they are leaking. Pressure test and see what happens.

[hellssephiroth]

yep replaced seals. I had it completely apart. How do you reset everything? Just by going into the sas mode or whatever in evoscan? If so I did it, pressure tested again and everything checked out. I got the idle down to 1200 but i had to take off the top thing for the cruise to get it there. The throttle lever right tight to the SAS screw, I didn't mess with that screw when i had it apart, and it still runs high. Its almost like it has to be drawing air from somewhere but i dont get it because im not finding leaks.

[hellssephiroth]

Should I mess with the SAS screw then? It seems like with the cruise bubble screw thing (sorry I dont know what its called) on It is keeping the throttle too far open. It does still choke off though if i rev it and release :( or if I try to coast with my foot off the gas get ready for a mechanical bull ride.

[hellssephiroth]

Also i adjusted the throttle cable just enough to remove slack but not open the throttle plate. Then I adjusted the tps to read 11%. Is that the correct way to do it?

[green-lantern]

What are your fuel trims? Do you have a wide band? Try unhooking the battery for a bit so the ECU resets and see if it starts running OK again. I have a feeling the GM MAS or something isn't right so the ECU keeps adding fuel because it thinks you are running lean. Are you running stock injectors?

[green-lantern]

Also you might try switching back to stock MAS and see how it runs. That way you can see if it's the GM one or not.

[dbest671]

One quick question, how did you get the screws out of the shaft? If you used an impact driver, or used any real amount of force you could have bent the shaft or throttle plate. I've bent a couple of throttle plates just doing the screws by hand. Now I just easy out the screws after bending two shaft and three throttle plates.

Alright, the SAS screw (the thing the throttle lever touches). Loosen nut and turn the screw out until the lever no longer touches it. Then slowly screw it back in until it touches the lever... once it touches the lever turn it an additional 1-1/4 turns. Then tighten the nut. Flip the throttle plate all the open and let it go (slam shut basically). Now try to reopen it, make sure it isn't sticking.

For the dashpot, I'm assuming that what you mean for the "cruise bubble screw thing" LOL, is the black hat one or the one with a vacuum line coming off it? With the throttle plate closed, are you able to push the pin/screw on the dashpot in at all? If you can't push it in at all, then you need to adjust it. But look at your SAS, if your throttle lever is touching it with the throttle plate completely closed, it's not a dashpot issue ;)

Also, you turned the springs a full two rotations right?

For the TPS... usually on a properly set TPS I get between 12.5-13.6% on a datalogger. I've never had one at 11%. I don't set them with a datalogger, but I will occasionally check them with a datalogger. You will need a multimeter and a .65 feeler gauge (good luck with that one, I had to order one). A 27 feeler gauge thing from Autozone will make a .645 one I believe when you put two of them together. But I live in Ford/Chevy country and they didn't have a straight MM one LOL.

Engine: Adjust Throttle Position Sensor (TPS) - 3000GT/Stealth Wiki (http://www.3swiki.org/Engine:_Adjust_Throttle_Position_Sensor_%28TPS%29)

[hellssephiroth]

Awesome thanks April ill try adjusting it a little more. I just got the plate screws out with a screwdriver i got lucky i guess.

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[hellssephiroth]

Oh yeah i turned the springs twice. I had to redo it already lol im like wow thats not a lot of tension.

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[hellssephiroth]

Oh one thing i forgot to ask is the butterfly in the middle supposed to close completely vertical or be at a little bit of a slant? Mines not perfectly straight up and down.

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[dbest671]

No, it's not supposed to be closed all the way, it's open ever so slightly... that's what the 1-1/4 turns with the SAS screw is. It would stick if it closed all the way. But if it's open to much it's letting in too much air. Also check your FIAV, make sure it's closing when it's warm.

[hellssephiroth]

How would i find out if its closing? Oh and does it matter what way they coolant lines are hooked up?

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[Roybatty]

Also you might try switching back to stock MAS and see how it runs. That way you can see if it's the GM one or not.

I 2nd this, when I had stalling issues...it was MAF related even tho it passed the tests in service manual.


How would i find out if its closing? Oh and does it matter what way they coolant lines are hooked up?

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Edited... April has this handled :thumbup:

[dbest671]

How would i find out if its closing? Oh and does it matter what way they coolant lines are hooked up?

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For the FIAV- I would image it does matter, but IIRC you can't connect them backwards because the one hose is too short. To make sure it's fully closing would require taking off the lower portion. Run hot water through it and watch to see if the spring compresses. You can use a heat gun too, just watch to make sure you don't get it too hot.

When you say it idles at 1500rpm, is this a cold idle or warm idle? If it's warm idle, what does it do at cold idle? If the cold idle and warm idle are the same, then I would suspect the FIAV isn't closing.

[hellssephiroth]

I found a feeler gauge at the store. Ill mess with it tomorrow hopefully and change my hoses around.

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[hellssephiroth]

Heres a video of what its doing, the idle is where i want it to be, but it is still doing this......... ugh soooo frustrating, even tried unplugging both the o2's, boost tested ..... again...... it held high enough to wreck my boost plug.
I even grabbed a smoke machine to see if i could find anything leaking around the TB just to make sure... notta.

http://i446.photobucket.com/albums/qq185/Hellssephiroth/th_20130724_115438_zps68f1fa8e.jpg (http://i446.photobucket.com/albums/qq185/Hellssephiroth/20130724_115438_zps68f1fa8e.mp4)

[hellssephiroth]

Does the IAC get warm naturally? I tested it with a multimeter and it tested 35 ohm all the way around. Before the video when the car was cold it seemed to not to choke off. Once the car got up to temp it started doing it. I noticed the IAC was warm so i let it cool and just let the car sit on on without starting it and it warmed back up. I did rip it apart and clean it with electronic cleaner and it didn't help. I will try later again to see if it still runs good when i first start it up cold. Idle is still where I want it though.

I'm going to order an IAC and pray thats the problem.

[2faststealth4u]

Mine did this and it was the ground connector to the battery :/

[dbest671]

The ISC can test good with a multimeter but the internals can be bad. Is it the original ISC (brown plug w/ aluminum housing)? It could be sticking. Don't think it should be an issue, but your dashpot is missing a piece that makes it functional. I know people delete these with no ill effects, but since it appears to be an issue on deceleration, it might be your problem as well. Your throttle plate (butterfly) is slamming shut because the part missing provides a resistance for the throttle plate to close slowly when you let off the gas.

[hellssephiroth]

Oh are you talking about the air filter thing? I normally have it on there but ill check to make sure if it solves it or not.

Tried it after work. Still the same. It does provide resistance though so i dont think its shot.

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[hellssephiroth]

The isc is the original brown aluminum one. I just ordered a replacement. For 40 ill try it and hope it works

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[hellssephiroth]

Ok so i threw on the new iac. Idles way better but still has the choke off issue :(

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[hellssephiroth]

Hmm is there a way to make the dashpot harder to push in?

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[hellssephiroth]

Figured it out. At least i can drive it like that..... Ugh still runs super rich.

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[hellssephiroth]

Ok, hypothetically if my TPS seems to work and when i test with a multi it has continuity or not depending if it is seeing idle switch I would assume but when I look on evoscan it doesn't show it working will it mess everything up? Is it really not working but its testing good with the multi? I got it driving decent, just not how it used to be it just seems out of whack. For whatever reason now I'm running lean at idle like 15-16 afr (wideband probably not accurate anyways at idle). It seems to be close to normal when I'm driving it though. Oh and oddly enough when I let off it spikes lean now instead of rich.... still on blow through doesn't make a lot of sense to me.

[hellssephiroth]

The one good thing is it feels like it is pulling so much harder. Again dont know why it changed all of a sudden.

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[hellssephiroth]

Weird, now im running a good afr at cold idle but when warm idle kicks in it runs lean and shuts off. Messed with sas and it still does it.

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[hellssephiroth]

Ah i see had to change it to 1 bit

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[hellssephiroth]

Hmm idle is good now bit it still runs super lean when i let off the gas for a few seconds..... Why me

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[Roybatty]

Hmm idle is good now bit it still runs super lean when i let off the gas for a few seconds..... Why me

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That's normal.

Revel in your time

[hellssephiroth]

Its so lean though i have hesitation when i get back on the gas. Im talking like 21 afr

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[hellssephiroth]

So it looks like the car randomly fixed itself again. Went out this morning fired it up and it ran like a beauty. I just don't get it sometimes. Wish I knew what it was so I would know where to look next time.

[hellssephiroth]

And back to running like crap.... Now i had a random incident at some stop lights where the car revved up to 4k and down to 500 over and over. Just like i was slamming on the gas and letting off. WTH :( i also notice on the stock boost controller it maxes out if i even tap the gas. Either it is shot or something rlsr is going on.

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