Buck/Stall after Boost

[Flavoade]

Shorten this story up:

My problem is 5-10 seconds after moderate to high boost the car will buck and then stall. I have to hold the accelerator and let it rev for it to stay running. After about 1-2 minutes the car will run normally. I dropped my fuel tank and found trash thinking my fuel pump was sucking debris out of the fuel tank. The problem is still showing up. To clarify this problem happens AFTER boost, not during. I can build boost all the way to 7k with no problems, but shortly afterwards it will stall.

While I had the car I noticed a strange smell, like burnt wires. My theory is that the wires for an oxygen sensor are too close to the turbo and are absorbing the heat and causing the sensor to malfunction, and that the reason the problem clears up after a couple minutes is because it has cooled back down.

Fuel system is:
Walboro 255
Evo III injectors
New Fuel Filter
Lines have been blown out
New Fuel pump strainer.

My BOV is recirculated

******UPDATE**************
The primary problem turned out to be the honeycomb structures in front of the MAF. They were moving around and caused misreads. I lost one of them, but the other was reinstalled and the car runs great now. They will be glued in place to prevent this from happening again.

Scroll down for the full resolution.

 

[clipto]

Imo start just looking over the engine bay if something doesnt look to your standars clean it up or move it around a little. Keep stuff away from heat and best thing is to go over this check list in this link and make sure everything is up to par, oil pressure coolant level, sparkplugs, and every other small thing. http://www.dsmtuners.com/forums/ecmlink-tuning-log-file-advice/443297-please-read-before-you-ask-ecmlink-dsmlink-log-advice.html Also if your free i recommend this to u and all put your fuel mods in your profile if there stock put stock if there aftermarket fuel pump or injectors post it up on your mod list.

 

[issac712tsi]

Sounds like a good story, I would like to see a post of your fuel mods.Also I would do a BLT and check the ignition timing with a timing light as well.

 

[Flavoade]

I should have clarified my diagnosis. The fuel tank was dropped and we found grass and tree leaves and the Fuel pump strainer was clogged, but once everything was back together it was still doing the hucka-buck. The problem only appeared AFTER boost and 5-15 seconds after boost. It does not show up babying the throttle, but only after moderate boost is used.

I updated my profile with the list of mods, that I discovered. I do not know everything that has been done to this car, but I do know not all of was done right. It was owned by a guy named Chris in North Carolina, and then Ivan in Baton Rouge.

I noticed a couple of loose wires that looked as if they were suppose to connect to the MAF, but a 2G system was installed, but I dont know if it was done right. The emission system on this car has been removed as well.

I don't have the car so this is all memory.

Can boost leak problems appear 5-15 seconds after the turbo was used?

I'm tired

 

[Breezio69]

Most boost leak issues appear as you are trying to boost, i recently blew my jpipe out of the threads (still dont know how) and it wouldnt get above around 3-4psi vacuum without bucking and almost dying. The only thing I can think of off the top of my head, after boosting is a non circulated bov while you are running a maf. Thats within the time of letting off the throttle though, almost immediate.

Post a pic of your connectors, maybe a relay or solenoid is supposed to be plugged in and its not? Hard to tell.... do you have a wideband? Does it go straight lean or rich?

 

[Flavoade]

It has a AEM Air-Flow gauge, if that is a wide-band?

My mechanic recently told me that it is running rich when the problem surfaces. He says he will try to tune it through link and will replace the speed density thing if he has to.

Will a bad tune in link cause issues like this, or does it sound link my MAF?

I was also wondering if you guys could provide me with copy of your tunes in Link? I want to try different working tunes to see if it helps.

I remember he told me he was having issues with Link losing the adjustments he made when the car would lose power.

 

[Dsmkauai]

Do a boost leak test to 20-22psi and report back!! You would really benefit by learning ecmlink's software bro! It's not to hard to figure out especially with all the help on the website and forums! If you want help here post a log and others can look at them and tell you what's not right. Start by looking thru the tutorials on ecmlink website! All speed density means is its using a map sensor and iat to calculate airflow and temp vs the 2g maf which is reading air coming in. I suggest you get used to looking in here ! It will help a lot trust me! I suggest getting rid of the 2g maf and just tuning with speed density. Once you learn alittle more for now you can use all the factors to help tune. http://www.ecmtuning.com/wiki/

 

[Flavoade]

Clipto you may have been right on the loose wires.

Guys I found out that the car has been running rich. The shop "found" out that the wires for the temperature senor came out of the connector and they pushed them back in; that is their claim. He said the temperature senor was telling the computer the engine is cold and was sending more fuel to 'warm' the motor.

During the install of my motor, one of the shop hands CUT one of my wires that was leaving the O2 Connector; HE CUT IT, and now he doesn't know where it goes.

To anyone that is new to doing this kind of work NEVER EVER cut a wire that you don't know where it goes, especially if the thing its going to still needs that wire.

I need your help bad guys. I am sure some of you are running similar setups to mine and can tell me where this wire goes.

It is the red and white wire with a purple wire spliced on the end, I need to know where it would go:

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I have ECM link, boost controller, turbo timer, AFR gauge, boost gauge, and exhaust temp gauge.

 

[mitsubishikid]

I wanna say it's your aem air-flow o2 gauge signal wire, I could be wrong.
best advice I have is trace the purple wire back and see where it leads you.

 

[1G Eclipse94928]

Clipto you may have been right on the loose wires.

Guys I found out that the car has been running rich. The shop "found" out that the wires for the temperature senor came out of the connector and they pushed them back in; that is their claim. He said the temperature senor was telling the computer the engine is cold and was sending more fuel to 'warm' the motor.

During the install of my motor, one of the shop hands CUT one of my wires that was leaving the O2 Connector; HE CUT IT, and now he doesn't know where it goes.

To anyone that is new to doing this kind of work NEVER EVER cut a wire that you don't know where it goes, especially if the thing its going to still needs that wire.

I need your help bad guys. I am sure some of you are running similar setups to mine and can tell me where this wire goes.

It is the red and white wire with a purple wire spliced on the end, I need to know where it would go:

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I have ECM link, boost controller, turbo timer, AFR gauge, boost gauge, and exhaust temp gauge.

You should figure out if you have a wideband or a stock o2 sensor because without a wideband you could have a bad tune, and I would check every inch of the fuel lines.
Sounds like that shop doesn't know there shit if you have dsmlink and there saying they dont know where the wire goes??!! I would make them compensate me to take it to another shop who will be able to fix it easily.. Honestly If i was looking at it in person I could tell you for sure, but I would assume thats the aem wire?? Ill tell you this for sure, it isnt a stock wire. look around and look for where he cut it off of.

and you don't have your heat shield over the turbo

E: pic #3 from top the blue and white wires look like the stock o2 sensor....

 

[rebelboost]

I have two sets of sensors at the spot your referring to, so it should be one or the other. Also, jump ship with you mechanic, I don't trust him.

 

[Flavoade]

Lol! If I told you everything I have been through with my car you would have an aneurysm. The mechanic is good, its just his goofy shop hands. They have cost him tons of cash blowing up motors and other stuff. He also knows DSMs very well, seeing he was at the local Mitsubishi service department when our cars were new. He also built motors, trannies, diffs for our cars on the side. He has mishaps and it has been adventure with this guy, but honestly my timing belt breaking and this mechanic are the best things that ever happened to my car.

He also has a 90 GSX with a titanium engine, twin turbo setup he built himself.

To 1GEclipse:

I have a AEM AFR gauge on the car so the O2 Sensor is definitely added. I guess the mechanic is going off of his hands word that he cut it, but I don't think it was connected to anything it was just laying there. The Mechanic deals with A.D.D. or something like that.

I noticed my AFR gauge is still working(or is it?) when they started it up. Do you guys think it sounds more like a jacked up tune than a loose wire? My AFR was 11.0 on a cold start but the problem is continual now, so as soon as it started showing symptoms the AFR went from 11.0 to 17.0-19.6.

The guy told me he had problems with Link losing the tune if the battery was disconnected. When they tried to start the car the battery was dead, and they had to jump it. I drove this car home out of boost and did not have any problems and it was reading 12.7 AFR.

I wanna say it's your aem air-flow o2 gauge signal wire, I could be wrong.
best advice I have is trace the purple wire back and see where it leads you.

The problem they made is that they cut the wire, and now they cant find the other end. So they don't have anything to trace.

I do have the AEM gauge and dsm link. The shop is saying that the AFR gauge is wired into link through the fuel control(PCM I think is what he called it). Do you guys know if the wire goes straight to the gauge or does it connect indirectly to somewhere else?

I looked myself, and I dont know how they lost the wire but they did it.

 

[mitsubishikid]

So I'm gonna guess they wired the aem uego wide band to pin 4 on the e.c.u?

of course you could always sit down with the guy who cut the wire, and see if he... ahem, his hands remember tugging it out of its socket, or maybe they used a pair of wire cutters to clip it off neatly.

obviously if it was cut nice, and clean with a wire cutter the other side of the purple wire cant be too far away,but if it was tugged out of the socket... well now you need to check all the connectors.

I found this article on aem install.
http://www.dsmtuners.com/forums/art...-wideband-2g-turbo-place-stock-o2-sensor.html
post 2 in the link above shows the installer cut the blue wire out ...

 

[Flavoade]

Kid, I am not sure whats going on anymore, but I am losing patience. They did cut the wire, but wherever they cut it from must not be on the car anymore.

It looks like I may have bigger problems. I got tired of waiting and I tried to pick the car up from the shop bring it home and play with it myself. I didn't bring it home as the car is doing the problem all the time now. I was afraid the rich/lean would mess up my freshly built motor.

The guy is saying that my idle control valve, and possibly even my ECU or Link may have crapped out. I am getting frustrated because I have owned the car for almost 2 years and it has been at his shop 95% of that time. I don't know if it is a wire or whatever, but I know it will barely hold an idle.

Good news is I finally got VIDEO!!!!
https://vimeo.com/87367405
first vid is me trying to send more fuel to see if it will run better
https://vimeo.com/87367404
second vid is the car idling on its own for a little bit after I had held the throttle until it warmed up a bit.
https://vimeo.com/87367403
third vid shows the typical symptoms I am experiencing

It still doesnt make sense. It was running great even with the messed up wires while he was driving it, and it ran ok when I brought it home. Now it is barely drivable.

 

[mitsubishikid]

In the third video it looks like the idle is sweeping up and down. I helped my buddy who is a member on this site, he had the same kinda issue the idle would keep going up and down back and forth, some times it would just kill and not idle at all.
we found the issue was the I.S.C or idle speed control motor it was bad, but a bad one can also sometimes cause your e.c.u i.s.c drivers to fry, so don't drive the car before you test the i.s.c motor, see if it is working like it should might also want to test it with an ohm meter.
hopefully you didn't fry the drivers in the e.c.u.

here is a link to a you tube video it shows what it should be doing
[ame=http://www.youtube.com/watch?v=l7R3gf7SiAo]DSM ISC - YouTube[/ame]

 

[Flavoade]

In the third video it looks like the idle is sweeping up and down. I helped my buddy who is a member on this site, he had the same kinda issue the idle would keep going up and down back and forth, some times it would just kill and not idle at all.
we found the issue was the I.S.C or idle speed control motor it was bad, but a bad one can also sometimes cause your e.c.u i.s.c drivers to fry, so don't drive the car before you test the i.s.c motor, see if it is working like it should might also want to test it with an ohm meter.
hopefully you didn't fry the drivers in the e.c.u.

here is a link to a you tube video it shows what it should be doing
DSM ISC - YouTube

The shop said he wanted to change that part. I should have written that in the videos whenever the idle is surging up and down that is me playing with the accelerator. It would not run for more than 3 seconds on its own; sorry about that. The second video showed the car briefly holding idle by itself after I kept it running for a bit.

If it was running rich, my plugs are probably done. My plan is to change them and see if it runs better, and to check if it still runs rich. He did fix the temp sensor, so if that was the problem when the new plugs are in it should run good.

My theory is: The car was running so well at first because the sparkplugs were still in working shape, which is why the shop was able to drive the car with no problems, but after a while the temp senor problem made the ECU foul the plugs with too much fuel and when I finally got my hands on it the plugs were almost dead.

Well see...

 

[Flavoade]

I went to the shop with a new pair of copper NGk 6EY's and my laptop. I swapped the plugs to see if it would change anything.

When I got the plugs out I found this:

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The plugs were NGk 7s and they were Iridium. The shop guy said he had a big box full of em so I guess that's why he used them. You can see how the spark-plugs were doing. After the swap I noticed the car starts easier and idles more smoothly, but it still dies after 3-5 seconds

Here is a video of what it is doing:
https://vimeo.com/88012877

I hooked up to DSMlink with my laptop and was able to talk to the ECU. According to the ECMlink wiki: The CEL, the boost gauge and no strange sensor readings in link pretty much means my ECU is not bad. I changed some settings and flashed them to the ECU and it successfully saved.

My next task is I will check the ECU just to be sure it isnt leaking. The shop connected the temp sensor, and that is the only thing they changed, so I will disconnect the temp sensor and see if it runs with the new plugs.

If it does keep running with the temp sensor disconnected I will check to see if the temp sensor is bad or if there are some bad values link.

While I was in link the DTC gave me two codes:
0012 - Volume Airflow Circuit Malfunction
0031 - Knock Sensor 1 Circuit Malfunction

I cleared the codes and only 0031 kept coming back up. Does this mean anything?

I will disconnect the the MAF and see how it runs as well. Is there an option in Link to open-loop the MAF?

Thanks guys

 

[Flavoade]

The issue has been found and solved! I disconnected the MAF and it kept running. I take the MAF off to clean it and when I look into it I notice that a piece of my honeycomb is just laying there. I show the guy and he puts it back in, we hook everything back up, car is running PERFECTLY now

So for anyone following behind me, it was a compound problem of:
1. The temp sensor wire broke and that was reconnected - the reason the car ran so rich.
2. The spark plugs were swapped out as they were killed by too much fuel - caused by the temp sensor not being connected
3. The Honeycomb structure in my intake was loose and flapping around. I lost one of my honeycomb structures(Got sucked in through the main inlet). - The honeycomb was moving around deflecting the airflow causing the MAF to misread. Also the guy said when the honeycombs are removed, sometimes the car will behave just like mine did.

It took a while but we got!!

P.S. As to why the honeycombs popped out; The guy believes that back pressure from the turbo gradually wiggled the two honeycombs loose.

 

[Flavoade]

After thinking about it, I realized that unless my car is a magician that metal piece of honeycomb did not just disappear. I am sure the turbo ate it up pretty good, but the fragments must be stuck in the intercooler. If this car was N/A the motor would probably be dead right now.

I am going to check my intercooler for the fragments and see if I can clean it or have to get a new one.

 

[mitsubishikid]

Glad to hear this got resolved man, lets all hope your inter cooler setup is okay for another round.

when i get link, i'll really make sure I hack all the honeycomb out of my 2g maf I plan on running in my 1g, and thanks for sharing your feedback on here flavoade.

 

[Flavoade]

Glad to hear this got resolved man, lets all hope your inter cooler setup is okay for another round.

when i get link, i'll really make sure I hack all the honeycomb out of my 2g maf I plan on running in my 1g, and thanks for sharing your feedback on here flavoade.

I seek help, so I can help others

I wanted to wrap up with this final update,

I thought my mechanic was going to replace the missing honeycomb with one he had at his house and glue, or just secure them so they would not pop back out. Turns out he did not so i got to do it.

I went to the junkyard and found a 95 3000SL that (Thank God!!) had the matching honeycombs(DSMs are dwindling). It was the only car in the yard that not only had the 2G MAS, but the exact honeycomb structures.

The reason the honeycombs popped out(I am still open to sabotage) is because the plastic retainer that sits over the honeycombs was removed! I only realized mine was missing after dissecting the 3k.

I also discovered my intake snorkel is violently vomiting air which may have pushed them out, but that is another thread