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[N/A to Turbo conversion] hesitation after 3000 RMPs

GTX

Well-known member
Joined
Apr 13, 2012
Messages
100
Location
Toronto, Canada
Hey gurus,

Once again need your help! /ubbthreads/images/graemlins/smile.gif
I'm converting my N/A Galant to 90-92 RS spec. Have MD165808 ECU, 510cc injectors and TD05 16G turbo, 2G MAF

Here is my setup:
1. Newly build engine, oil pressure is fine, compression is fine, spark plugs are new, wires are fine
2. Turbo is new, intercooler, piping is done well.
3. 2G MAF is used, I hope it works. Converted all connectors, verified all ECU links, verified pin6 and pin 14 issue for 91+ cars.
4. Connected High Pressure Line (from intake right in front of the intake) to the waste gate actuator. The Waste Gate I have works off the high pressure, verified. Tried to put the manual boost controller in the middle, but this thing is crap, did not do anything at all. May be I'm connecting it wrong.
5. Connected BOV to the vacuum line in intake, helper pin to high pressure line (to compensate and ease up the opening)
6. Getting about 10 PSI boost at 3-4k RPMs

Getting two errors:
1. Knock sensor error ( I think is dead, as I cant see any impedance at all, not evem Meg.a Oms. So it is birned ( as well as the second one I have). It is a microphone after all, so some impedance should be present.
2. Getting Air Temperature Sensor error. Verified the connection, it is fine. Not sure why there is an error.
Here is what is happening:
1. Idle is fine, about 1000 rpm
2. Ignition is 8-10 degrees at idle
3. When accelerating the car gets to 3000rmm then hesitates, if I get of the gas, it stalls.
4. If I rase rpms slowly at any gear it runs better, but once reached 4000 rpms starts hesitating.
What is going on? I have a feeling that there something wrong with AIR/FUEL ratio once RMPs go high. I don't hear the knocks, neither car backfires. any ideas? I have the logs if needed.

Thanks,
A.
 

GTX

Well-known member
Joined
Apr 13, 2012
Messages
100
Location
Toronto, Canada
Forgot to mention: fuel pump is upgraded to Walbro 255
 

AllanL

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Aug 4, 2008
Messages
294
Location
NV
2G MAF is 'tuned' to the 5808 JDM RS ECU?

plugs fouled?

tps set correctly?
 
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GTX

Well-known member
Joined
Apr 13, 2012
Messages
100
Location
Toronto, Canada
None of that is done. could you please explain the details?
 

AllanL

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Aug 4, 2008
Messages
294
Location
NV
here's a start: click

there are a lot more on this subject, try to search...
 
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tektic

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Joined
Dec 19, 2012
Messages
1,497
Location
ronkonkoma, ny
Short answer is you need to let you ecu know your using bigger injectors and an entirely different maf. If your running a stock nt 9:1 compression your going to have to back the timming off quite a bit too. It will never run well without tuning.

Get your eprom tuned, get link, or mega squirt or aem.I'd say afc, but I don't want to recommend it.

If your getting a temp sensor error your wiring or your maf is not good. Same with your knock sensor.

Idle is high at 1000rpm that's not correct. What's your base timing set at (with plug grounded)?

Your waste gate should be conected to your turbo outlet for the best signal. Just in case, Neither the waste gate nor the bov should be connected to the tb. Never T these lines together either.


 
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toybreaker

iconoclast
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Apr 30, 2006
Messages
3,581
good advice above

Do a boost leak test, and fix any/all leaks!
 

GTX

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Joined
Apr 13, 2012
Messages
100
Location
Toronto, Canada
Here is the thing guys, I have tested the boost leak, everything was fine, checked the plugs - fine. Then decided to change the ECU, just to test. I had another one, which was pulled out from 89 Colt Turbo. And...magic! Everything runs fine now. Well, at least no hesitations, a smooth revs. So, here is the question, what needs to be done to JDM ECU to run smoothly with 2G MAF?
 

swe_gvr4_1991

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Jul 27, 2006
Messages
177
Location
Sweden, Alingsås
Quoting GTX:
So, here is the question, what needs to be done to JDM ECU to run smoothly with 2G MAF?



The bare minimum is to have a chip burnt with the 2G MAF compensation maps in it. The MD165808 ECU (E952 chip) is already setup for 510cc injectors but will not handle the 2G MAF properly.
 
Last edited:

thomcasey

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Sep 24, 2014
Messages
907
Location
Indianapolis, IN
510's are too small for a 2gMAF. You need to be running 560's in a normal USDM setup with a 2gMAF. If that JDM ECU is essentially the same as a USDM in injector requirements, then get some 560's from an EVO and see how she runs. IF the ECU requires 510's, then you might look into some PTE 680's (they actually flow like a 640, which just puts you a tiny bit over the 20% increased airflow measurements from the 2gMAF. Still this is very iffy as your injector deadtimes with the 680's will not be the same as the 450 or 560's, so you may still see some hiccups and may run a bit rich with strange timing adjustments by the ECU.
 

GTX

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Joined
Apr 13, 2012
Messages
100
Location
Toronto, Canada
Hey guys, just want to update this thread for the benefit of other folks who would choose to go with N/A to Turbo conversion:

So, as above thread says I have run into a weird problem, where the engine would start bucking at 3000 rpm and would do it only when warmed up, as well as it would not hold a steady idle. I was banging my head against the wall, as all normal routes of troubleshooting were taken with no results. Even Idle Step motor was replaced as well as FIAV disabled, still no luck! No boost leak as well.

Guess what was the problem? Here it is: when you do the conversions you need to replace/update quite a few things. I will not go into details, as there is enough resourceful threads about it here. But one thing is not mentioned. When you install a turbo MAF you should rewire the exiting connector, right? Right! You follow the instructions and diagrams, right? Right! The diagrams we have here in the library reflect 1G and 2G Talons and Galants. In my case, I was looking at N/A version of Galant. Guess what, the wiring in the car was not reflecting the diagram. Yes, the wires are connected, say MAF input goes to the right pin in ECU connector. However, how would I know that somewhere in the middle of the harness that wire is hooked to another device/source? That was the case for both MAF and Air Temperature wires. The temperature one was easy to spot as you see the reading of it, but MAF signal was just deformed by some other electrical signal. Unless you get the oscilloscope and have one of those expensive readers, which give you the shape, how would you know? Anyhow, my advice to newbies like me, if you want to put something new into the car, assume your wires may have junctions, unless you open the harness and see for yourself. In my case it was much easier to make another MAF dedicated harness and bring it to the ECU. Would of saved me a lot of time /ubbthreads/images/graemlins/smile.gif
 

swe_gvr4_1991

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Jul 27, 2006
Messages
177
Location
Sweden, Alingsås
Thanks for getting back with info.
Make sure you have the MAF reset wire hooked up also.
 

tektic

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Dec 19, 2012
Messages
1,497
Location
ronkonkoma, ny
I wired in an evo maf to a non turbo ggsx harness... Mine worked fine. What was connected to yours?

If my car was breaking up, I'd expect it to be knocking and pulling timing.
Do you have any way to monitor knock or afr?
 
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