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(Resolved) Brick wall around 4000 RPM

DavsR

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Joined
Aug 25, 2011
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83
Location
Sacramento CA
I have never posted in the discussion area of the forum, so my apologies if this is in the wrong area.

PROBLEM: Car will not drive past 4-4.5 rpm and when boost is built it goes immediately rich, timing doesn't always get retarded. I have ECMLINK v3 and I do not log knock during the time that timing is retarded. Boost will only build to 3-5 pounds then I have to let off the throttle because my AFR jumps to 9:1. When I accelerate WOT or past RPM range it starts to feel as if I hit a wall and or lack of fuel or spark. In normal low rpm driving car accelerates fine and the car idles perfectly. Freeway driving is fine as long as i don't accelerate rapidly. I do notice that when i'm shifting between gears the car goes rich instead of immediately lean.

ATTEMPTED SOLUTIONS: Problem started after my ECU Burned up, literally caused a small fire in the ECU. I've replaced TPS (1g and 2g), CAS (green top), ISC (black) and ECU (rebuilt like new); all seem to be in working order. I have my Front O2 being simulated currently since the wires have cracked on two of the four and one is completely broken. I have base timing set at 5 degrees and TPS volt at .63; My current maps are set after the evo 8, but changing back to stock makes no difference.

IDEAS for SOLUTION: I think I'm going into OPEN loop as soon as the car see's boost which is causing me to run extremely rich. Car jumps from 14.9 to 9 as soon as a little boost is present. I think it maybe associated to my front O2 Sensor problem, but I though that if I had it simulated then the ECU would not use it for OPEN/Closed loop. Another idea I have thought of is that I have a weak spark that is blown out at any level of boost causing my rich mixture with little to no knock.

HELP: If anyone has experienced this in the past or found a solution to a problem similar to mine I would greatly appreciate your input. Thank you ahead of time.
 
Last edited:

prove_it

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You have a Pm coming your way.
 

prove_it

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Sioux Falls, SD
You say your simulating the O2, which WB sensor and controller are you using?
 

transparentdsm

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Cherry Hill, NJ
go on tooners and find tedspec, he is in your area and a very smart guy. sounds to me like your tune is off or maybe you have the no lift to shift activated and the wires are backwards. you have changed a lot of things and using the evo 8 maps isn't the best solution unless you have evo 8 injectors, maf and FPR set to that maps fuel pressure.
 

prove_it

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I got his log, looks like a MAF calibration issue. Not positive, but there is no MAF correction in the graph.

Just need to clarify which MAF sensor is being used. What number is on the sensor?
 

Turbo99

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Oct 9, 2013
Messages
79
Location
Haverhill, MA
I know it may seem strange, but make sure your CAS setting in DSMlink is correct. We had it looking for a standard signal instead of inverted in a dsm and it did pretty much the exact same thing.
 

prove_it

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The 1G ecmlink chip doesn't have an inverted CAS setting.
 

DavsR

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Aug 25, 2011
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83
Location
Sacramento CA
thanks for all the posts, I really appreciate your suggestions. I have sent Prove_it a log and will be sending him another this afternoon with all Values being logged. I'm running a 2G Mass and I do not have the no lift to shift setting working currently. I have another chip set up that I ran before I had ECMLINK, I tried it and still had the same issue. I then put my stock ECU back in my car and same issue again. I have the setting for narrow band O2 Simulation through WB on my EGR Signal, not sure what "controller" i'm using though. Below is a list of my mods as a remember them at the moment, I'll ad to my signature. THANK YOU once again!!!


91 Galant VR4, 2.0 6 bolt 2g piston rebuild, ARP studs(all), Mitsubishi MLS head gasket, 272/272 hks cams & AEM cam gears Not Installed currently, 550cc Inj evo8, AEM FPR @ 38 lb , 255 Walboro fuel pump, ETS FMIC w/2.5 pipe, ssq BV, FP 68HTA internal Wastegate (ported), FP Exhaust Mani Port Matched, LC1WB, 2.5-3 inch DP cat/delete 3 inch exhaust, injen intake 2g MAF w/K&N, V3 link full, NGK 7 Cold Plugs new, NGK Spark Plug wires, Timing set to 5 Degrees, all stock vacuum hoses correctly routed. 2G mass
 

strokin4dr

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Savannah, GA
Check to see if your cam timing is off a tooth. Sounds more like a mechanical timing issue than it does a tune issue.
 

Tommyd

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Jan 18, 2013
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Fishkill, NY
Is it a new or used AFPR? I've had one go bad and as soon as I hit any boost it basically blocked off the return line.
 

prove_it

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Well got the log open. I'll send you some corrections. Biggest thing I can see right off the bat is that your TPS never goes above 3.12V. I know you went WOT so there is an issue in that reading. I'm guessing it's a matter of adjusting it. Base voltage is around .63 which if fine, a little higher than I like, but will work ok.

You also threw code 0023. Camshaft position sensor malfunction. Given that you've replaced and been digging around that area, do you think it's possible you go the TPS and CAS wired up backwards? I would start in that area.

I really sounds like there is a wiring issue somewhere between the two sensors. Let's start there. After we get those sensors reading properly, we need to move to performing a MAF comp adjust. Your airflow per rev at idle at 1k rpms is around .21, which is way low. But like I said, get the sensors sorted out, then we'll do that.

Also I like to have the Lock Comm in Eculink box checked, as long as your not going to do emissions testing. This allows link to process data faster.

As for the EVO maps, your fine on those for now. It will run rich as hell through the powerband, which I have modded maps that will fix that, but that's the last step.
 

swe_gvr4_1991

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Jul 27, 2006
Messages
177
Location
Sweden, Alingsås
Ran into the same (fuel) rev limiter (when i was testing out a new fueling code for my SwD).
I wanted to check that the code was able to supply tons of fuel. So i set a ridiculous high VE (I run SD) and lo and behold a solid 4000 RPM rev limiter.
I run a almost identical setup as you with a 68HTA, 272 cams, exhaust side, Etc.
So i went and set a proper VE (AFR map value if you're running a MAF) and got the AFR up to around 11.0 AFR and the rev limiter was gone.

After that incident i did some research into this phenomenon as there is such a thing as over fueling rev limiter. Sounds crazy but it's true.


So check your MAF settings, AFR map settings, injector size, and deadtimes so that you're not over fueling.

Good luck!
 
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prove_it

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Oh it's over fueling, but like I said there are two sensors failing to read properly.
 

DavsR

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Aug 25, 2011
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Sacramento CA
alright guys I found the root issue with my car broken coupler clamp, which I found while I was replacing front o2. thanks all for your help!! but it does sound like I have other issue with tps and cas, both replaced used from junk yard I have several others so ill put them back in and adjust. the car was purchase in pretty bad shape, previous owner had hacked the ecu harness pretty bad. I have been resorting the car for three years and just started looking into proper tuning.

I have everything necessary to run SD but not enough knowledge to make it work. again thank you to the community its a real pleasure to have such good people with a lot of knowledge.
 

transparentdsm

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ok so im not trying to be a dick, but im going to be. if you have any hesitation with wiring/finishing up what you have call a specialist who knows his sh*t. CALL A LOCAL TO HELP, there are enough of them. this is the point where things can and will get bad real fast. if the wiring is crossed call someone. the last thing you need is it to fry the ECU or any other electrics and possibly cause a short. unless you dont mind figuring it out yourself and replacing things.

i have seen it, i have fixed it. electrical is something you really really dont want to mess up.
 

Diego

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Dec 9, 2007
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In a van down by the river, Iowa
Oooh your car # is close to mine.... /ubbthreads/images/graemlins/grin.gif
 

DavsR

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Aug 25, 2011
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Sacramento CA
transparentdsm don't think you sound like a dick at all Iit's good advice. I've been daily driving my car for two years with no electrical issues. the fact my ecu burnt up had to do with a random act from the Mitsubishi gods. I am no stranger to electricity and or testing for resistance, current, voltage ect. The TPS & CAS came off a junk yard car so they probably where no good to begin with. I actually contacted tedspec on tuner to tune my car in the next few months after I upgrade my injectors and ethanol sensor in order to run a dual stage tune for 91 octane and e85. I am new to ecmlink and don't know what readings are normal and which need adjusting. I WILL learn, but we all start some where :) Just need a little direction to start.

Diego our cars could be brothers lol jk
 

transparentdsm

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Jul 27, 2011
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Cherry Hill, NJ
ok cool, i wish you the best of luck with your car. if you need anything and i can help im only a 2 hour drive from you and i love the drive to sac. 2 years of driving it with no real issues is a win in my book. ECU's sometimes do just go bad, but not usually for zero reason, there was something in the car that caused it and you were prolly on the right track with the CAS and TPS, have you thought to check the IAC and the FIAV? its a 20+ year old car, so really anything could cause it. when i first had 1365 it had a similar problem and it went from one electrical gremlin to another. finally i replaced the CAS, TPS, IAC, stock FPR and the car still acted weird so i pulled the ECU and found a bunch of burnt up circuits. got the ECU rebuilt and with the CAS, TPS, IAC replaced with new OEM parts and an aftermarket aeromotive FPR the car ran great. these are older cars and in my opinion everyones problem is usually different despite the symptoms being very similar. its even harder not being able to see and hear the car in person to help diagnose what is wrong.

if your ever in the area and would like a second opinion ill take a look and fiddle around with it a bit if you want.

Ted really is the guy to go to. i plan on using him some time soon as well as im not good at the WOT portion of tuning with DSM link so i want a pro to do it.
 

prove_it

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Ecu's do fry themselves... Caps issues. Electrical gremlins in our cars? What, never heard of that.... /ubbthreads/images/graemlins/rofl.gif
 
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