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Issues with my Mighty Max swap

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kyledebo

Probationary Member
15
1
Oct 18, 2021
Leominster, Massachusetts
Hello my name is Kyle and I own a 1989 mighty max with a 4g63t swap on bags and all that good stuff. I'm having some issues with the build and I'm desperately looking for help. There is an old forum thread that I need to talk to the author and see if he or she has ever figured out the issue. Seems to be a bit of a rare one.
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So while accelerating there is like a "flat spot". If i reallyyyy ease into it the flat spot doesn't happen. When I'm on the highway I get about 9 miles to the gallon. Needless to say the truck is down on power. I just replaced the MAF that made the truck run much better but still have that flat spot. I've checked for boost leaks and I cant seem to find any but I haven't been able to do a major boost leak test. If I keep my foot down I can eventually get the turbo to build enough boost to push past the flat spot but the truck is still very sluggish. Did compression test not too long ago and solid on all four. Plugs and cables about a month ago and I change the oil often and the tranny fluid often as well. It does smell like burnt onions when I do that though which makes me think the turbo burns oil when I do that so I don't do that LOL. I don't know if there is correlation but this started happening not right after but soon after I changed my system from a BOV to a 1g recirculating system. I have since changed it back and still the issue persist. I do have the ECMLINK V2. I will be plugging a laptop up to it very soon but I don't even know where to begin with that stuff LOL. I don't want to touch anything and mess it up but I've been told it will tell me some vital info.
 
You need to give us a profile of what's in the car. You have ecmlink so use it. Data log and post it and fill out a profile so everybody knows what's what. We can't help you if we don't know what you have.
 
its a 6 bolt out of a 91 eclipse. 450cc fic injectors, aeromotive fpr, 16g from evo 8, 450 lph aem inline pump, 2g maf, straight piped to magnaflow muffler, any other info I'm leaving out that you need to know just let me know. I'm not going to be able to pull a log and stuff for a week or so due to general life things. I was making my first post so I could private message the person on the forums that was experiencing the same problem.

as the original reply says i will be using the ecmlink soon LOL so i get the fact i should use it i just havent had a chance. If someone has experienced this, or has dealt with it, the input is very much appreciated.
 
Try this. here is a couple stream captures from earlier. I was able to get it working tonight. First time using this though.

**edit** without knowing much I can see my throttle position and rpms are not what they should be. The o2 sensor seems it may be bad? and the timing is going everywhere. I don't have a speed sensor hooked up at the moment. I'm not sure if I don't have a knock sensor or what if that's even possible LOL or if its just not knocking. (I thought a very little bit of knock was normal but I probably made that up to make myself feel better)
 

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Without knowing the settings on ecmlink, fuel pressure etc we are flat out guessing.
I also pulled my plugs today and they were VERY black. All of them were equally black. I think i might need a new valve cover gasket. Im also certain my o2 sensor probably looks like my plugs. smh
 
How about the basics since you still haven't filled out a profile.
You're setup for a 2g maf. Is that what you're using?
What injectors are you using? Your global is -30%.
 
How about the basics since you still haven't filled out a profile.
You're setup for a 2g maf. Is that what you're using?
What injectors are you using? Your global is -30%.
I don’t know what you mean by “filling out a profile” I’m new to all this. Yes I’m running a 2g maf with 450cc fuel injector clinic injectors and i dont know what a global is
 
Who did the tune? I don't think it's possible for you to have 450cc injectors with those settings. Not from what you are describing.
It is difficult to help you because you have not told us what all is in the car. That is the purpose of a profile. Go into your account and you can add a vehicle and list all the mods etc.
Given it seems to be pouring fuel you either done have the parts you think you have or adjustments need to be made in DSMlink or both. First step is finding out what you have then adjust the settings for that.
 
Who did the tune? I don't think it's possible for you to have 450cc injectors with those settings. Not from what you are describing.
It is difficult to help younbecause you have not told us what all is in the car. That is the purpose of a profile. Go into your account and you can add a vehicle and list all the mods etc.
Given it seems to be pouring fuel you either done have the parts you think you have or adjustments need to be made in dsmlink or both. First step is finding out what you have then adjust the settings for that.
Okay I filled out the profile and I will add more later. I couldn’t tell you who tuned it. Also... Under further inspection I believe they are 650cc.

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What is the fuel pressure?
What is 10.5t in your profile?
I don't know what turbo that is but it is not a dsm flanged 16g. What exactly is it? You are running a non recirculating bov on a maf car. That's a problem at any vacuum condition particularly idle.
 
What is the fuel pressure?
What is 10.5t in your profile?
I don't know what turbo that is but it is not a dsm flanged 16g. What exactly is it? You are running a non recirculating bov on a maf car. That's a problem at any vacuum condition particularly idle.
The fuel pressure used to stay at a solid 40 but now it fluctuates from like 37 to 43. The turbo is a 16g off of an evo 8. And if I don’t put the “10.5t” in the turbo part number then I don’t get the correct flange turbo. It is a recirculating now. This issue actually started happening not too long after I changed over from a BOV to this 1g recirculating valve.

** I didn’t do these sketchy things to this poor truck. I bought the truck after it has been molested by many short cut takers. **
 
Check all your piping for leaks.
I have been through pretty much all of it. I have a silicone Coupling coming so I can get a better fit on my boost leak tester but it’s taking forever to come because it’s from China. I even have a new charge pipe as well Because I thought that was the issue but it wasn’t.
 
I have been through pretty much all of it. I have a silicone Coupling coming so I can get a better fit on my boost leak tester but it’s taking forever to come because it’s from China. I even have a new charge pipe as well Because I thought that was the issue but it wasn’t.

I’m fairly certain you can go to Home Depot/Lowe’s and get a coupler. A boost leak tester can be made for under $10.
 
So it was running correctly?
If so I'm going to say you have at minimum a boost leak.
Yes the truck was running fine one day and the next it had that flat spot. It also smells like burnt onions sometimes. I also noticed a little bit of oil By the plugs so I’m thinking I need a new valve cover gasket.
 
Like many dsm's, it desperately needs a tune. I'd set everything back to default and start over.
Im worried if its a mechanical issue and i just reset the tune without figuring that out ill be in the same spot. here is a couple updated pics of my engine bay.

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Where are those vacuum hoses on the throttle body going to?

Check ALL of this first. Don’t half fast it or you can be chasing your tail.

I mean I don't know exactly what they are going to... I've said many times now I'm new to this so I wouldn't know what all the parts its going to.. I'm assuming where they would go normally.. an egr valve or the FPR, maybe a purge solenoid, or any other place they may be used idk. I have tracked them and there is no splits or holes or cracks in them. The FPR vacuum line was pinched and I fixed that last night. Truck runs a bit better but still has the flat spot and now the check engine light comes on when its in that flat spot. Once I get a better coupling to do the leak test more efficiently I hope ill get some more answers. I'm also going to hook the laptop back up and figure out what's up with that check engine light during the flat spot. The light didn't come on before.
 
Track where they go exactly, pull the code and go through that check list in link above.

You can’t expect a car to run good with a crappy tune. What you put in is what you’ll get. I’m not bashing you, just stating the obvious. Not sure why the timing and fuel sliders look that way. They should be zero’d and maf slider should be smooth. That’s why I’m saying you need to start over.
 
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