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Well lucky for you you already have a chromed ecu, so you're halfway there as far as data logging goes. All you need is a laptop, the tactrix cable and a copy of evoscan to get up and running. Here is a link on how to get setup for chromed and evoscan: Chromedecu.org | Getting Started. You can skip the tuning specific parts unless you plan to change your tune. Once you have a log you can post it here, and someone will be able to tell you more.

If it is a tune problem, bboyalan could probably fix it remotely for you. He does charge for remote tuning work, but it would probably be cheaper than paying 3sx to look at it again.
 

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My old brain just kicked in and I think I might be able to help you.
My son was having a similar issue on his 93 VR4 and it turned out to be something that he had no clue about.
He was having issues at around 5000 rpm and it turned out when he flashed his last tune, somehow NO LIFT TO SHIFT got turned on????
It was set to trigger at, you guessed it, 5000 rpm....

He turned it off has been good ever since.

Hope that fixes your issue....

Bob.
 

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Discussion Starter · #25 ·
I wonder if i could try and do a no lift shift pull to see if that would verify your theory, but i have swapped ecus from a rebuilt factory ecu- to a chrome ecu. I would imagine that is where a ‘no lift shift’ thing would be stored.
 

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Discussion Starter · #26 ·
My old brain just kicked in and I think I might be able to help you.
My son was having a similar issue on his 93 VR4 and it turned out to be something that he had no clue about.
He was having issues at around 5000 rpm and it turned out when he flashed his last tune, somehow NO LIFT TO SHIFT got turned on????
It was set to trigger at, you guessed it, 5000 rpm....

He turned it off has been good ever since.

Hope that fixes your issue....

Bob.
I wonder if i could try and do a no lift shift pull to see if that would verify your theory, but i have swapped ecus from a rebuilt factory ecu- to a chrome ecu. I would imagine that is where a ‘no lift shift’ thing would be stored.
 

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I'm not sure where he found it, but he was beating his head against the wall like you.
He just started looking through his map, found it, and immediately turned it off and did a re-flash.
He runs a CHROMEDECU as well, has for a few years now.

Pretty sure for it to work CORRECTLY you have to do some wiring....but I run a stock ECU, so I can't help you much other than point you here...


Bob.
 

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If you want, I can ping him and see if he can tell me where he found it?

Bob.
 

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Here is the relevant post about no-lift-to-shift: Chromedecu.org | No Lift to Shift (NLTS)

In your original post it said the car will rev to redline in neutral no problem which I don't think would indicate NLTS was activated. Chrome needs a signal from the clutch switch to get NLTS to work. The only way I could see it would be if it was set up "backwards"(if that's even possible) and OP meant "neutral" he was talking about with the clutch pushed in.
 

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Discussion Starter · #30 ·
Here is the relevant post about no-lift-to-shift: Chromedecu.org | No Lift to Shift (NLTS)

In your original post it said the car will rev to redline in neutral no problem which I don't think would indicate NLTS was activated. Chrome needs a signal from the clutch switch to get NLTS to work. The only way I could see it would be if it was set up "backwards"(if that's even possible) and OP meant "neutral" he was talking about with the clutch pushed in.
Clutch not pushed in, i drove it today and tried out everyones theories. Im going to post a response after this to go a bit more in depth.
 

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Discussion Starter · #31 ·
Okay so i am the OP for this thread, i took everyones advice into a test drive i did about 30 min ago. I have a Scion Fr-s as a daily so it was a cold engine when i took the Vr-4 out of the garage.

I have had a theory that blown turbo seals on both front and rear turbos could be causing issues. ( I really should have gotten new turbos when i rebuilt this thing, it smokes bad when it gets warm. There was oil in the intake manifold when i did valve cover gaske IE OIL SMOKE in the combustion camber causing issues. So i did a pull with a cold engine, something i NEVER do. I pulled it out of the garage, (fired up perfectly). And did a pull right in front of my house right away, i hit upper 6500ish rpm before going to nuetral. It spun all 4 tires and had 0 issues. Then i cruised out of the neighborhood onto the highway, (coolant just getting up to temp and oil pressure still high). Then i did an in boost pull in 3rd gear, i had eased up to 3rd staying low rpm out of boost. The engine bucked at about 4k rpm. Good up until then, then i stayed out of boost in 4th gear (creeping up to see how far i could get out of boost) and it lurched back and forth at 3k rpm. ( i was easing into the throttle with vacuum pressure). Then i just limped the car back home.
Like i mentioned, the car idles, starts, and revs to redline perfectly. Other that occasional click click start or the teeth seem off on start up.

Afrs looked perfect throughout the drive and all the pulls, i have a coworker that is going to sit shotgun and monitor everything with his expensive snap-on obd2 scan tool to try and help diagnose the issue.

It seems to be getting progressively worse as i continue to drive the car, i have not done a boost leak check since i disconnected everything doing the valve cover gaskets 2 days ago. I need to do that again but everything got tighten up fine and looked good.

I know this is a long thread and it is hard to follow, i appreciate all of you trying to help me.
 

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No-lift-to-shift, if hooked up correctly, only works when the clutch is pushed in. Being in neutral shouldn't have any effect on it.

It's interesting that when fully cold you can do full pulls though. I wonder if you are having issues with the transition from starting to being at temp and open/closed loop fueling.
 

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You absolutely need to datalog the car as it sounds to me that you are getting some kind of fuel cut for whatever reason. If I were to guess, I would bet on the ECU seeing more air coming in than in reality. This could be due mechanical (boost leaks...), electrical (faulty MAS wiring/connection...) or electronic (faulty ECU or wrong settings in Chrome) issues that are causing the ECU to factor in wrong Hz values and triggering fuel cut.

In any event, you will not be able to narrow down the potential electrical and electronical issues without datalogging the car. I don't even see the interest of having a Chrome ECU without the tactrix cable... It's only 225 bucks with Evoscan and I am prettry sure it does everything your 400 bucks Scantool does AND allows you to datalog...

On a side note, I had a VERY similar issue when I installed the AFC Neo on my car and it turned out to be an issue with a programming bug in the AFC Neo that impacted the Karman function. As a result the ECU was getting incorrect Hz values... Apex AFC Neo: Confirmed Programming Bug - Karman...

Good luck!

Reda/
 

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The fact that you are not having the issue when the car is cold also points out to a fuel map issue. When the car is cold the ECU uses a warm up enrichment table. The ECU also uses a load based correction to eliminate enrichment during warmup at high loads so you don’t run too rich at WOT. As such, it appears that either there is something wrong in the fuel maps used by your ECU or in the values that your ECU is getting. Again no way of knowing without a proper log.
 

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OP mentioned AFRs. I sure hope that it comes from a WB because the uselessness of NB O2 readings Is a topic that has been beaten to death.

Trying to tune a car without a WB and without a daralogger is like hiring the services of a sex worker without proper protection (millennial vocabulary anyone?). Don’t come crying and asking for help when things don’t end well!

Reda/
 

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I had a similar issue on a different car with a turbo. you could accelerate fine but at a certain point it would literally lockup and try to throw you through the windshield. only on hard acceleration. I had some one do an engine exchange because I didn't have time. They connected 2 of the vacuum lines in the wrong location and confused the hell out of the turbo. So a quick inspection of vacuum routing can't hurt and it's free.
 

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Post up logs. Could be AFR related (warm up enrichment map) or could still be faulty electrical issue (electrical parts get hot and fail, PTU, sensors, coils, wiring, maybe fuel pump/supply wiring issue getting hot such as a relay). Datalogs would be very useful in diagnosis to see if the AFR goes lean or if it just shuts down.
 
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