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93 NA ATX 3000gt DOHC
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Haven’t read all this thread but looking at the crimp in that hard line, I’d say that might not allow enough fuel for above 5000 rpms. Was that already there or did you do it trying to break fitting loose? Just to be sure you know the male connector on hard line is fixed (does not turn on hard line). You have to hold it steady and turn female connector/hose together. If you try to turn male connector, you’ll crimp hard line like you see in picture (restricting fuel flow).

You have to break hose loose under car front of tank first and rotate hose assembly to unscrew it from hard line male fitting to pump hat.
 

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Okay so the most telling thing is you went from like 30 degrees of timing advance to 5 degrees the second you crossed 5k rpm. You then held at 5 degrees while still on the throttle and the second you left off it it jumped to 13 and started climbing again. As far as I know under normal circumstances that dramatic of a change in timing advance would only come with very high boost counts, of which you have none.

So it looks like something is wrong with your tune, but other more experienced people will probably chime in. Who did the current time for your car? You might have to throw them some money but there are several people who do remote tuning on here that are very familiar with the platform. They would probably be able to notice any glaring errors pretty quickly.
 

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Discussion Starter #23
Yes r
Haven’t read all this thread but looking at the crimp in that hard line, I’d say that might not allow enough fuel for above 5000 rpms. Was that already there or did you do it trying to break fitting loose? Just to be sure you know the male connector on hard line is fixed (does not turn on hard line). You have to hold it steady and turn female connector/hose together. If you try to turn male connector, you’ll crimp hard line like you see in picture (restricting fuel flow).

You have to break hose loose under car front of tank first and rotate hose assembly to unscrew it from hard line male fitting to pump hat.
Yes the line was already bent up like that. I was thinking that i would have to go from the other end of the line and turn it like how youre saying. I also didnt realize there was a fuel filter there so im going to try and straighten that out and replace the filter. It wouldnt hurt to just get a new fuel pump the more i think about it. Just to know what i have really. Thank you for the reply!
 

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Okay so the most telling thing is you went from like 30 degrees of timing advance to 5 degrees the second you crossed 5k rpm. You then held at 5 degrees while still on the throttle and the second you left off it it jumped to 13 and started climbing again. As far as I know under normal circumstances that dramatic of a change in timing advance would only come with very high boost counts, of which you have none.

So it looks like something is wrong with your tune, but other more experienced people will probably chime in. Who did the current time for your car? You might have to throw them some money but there are several people who do remote tuning on here that are very familiar with the platform. They would probably be able to notice any glaring errors pretty quickly.
The tune was by Dyno Pro technologies out of St. Louis, A friend of a friend owns the shop. Newly opened but they had 2 3000gt's in their shop so i figured that was a good sign. Their "expert" on 3/S was based out of New York, i forget his name but i had not heard of him.

With what you are saying about the timing, i really dont know much about that at all. Ill do some research and try to learn. Thank you for the reply!
 

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The 3SNY guys up in New York are pretty active, so it might have been one of them? You might have to get the tactrix and reach out to one of the tuners on here to have them look at it. Both familyMAN and bboyalan come to mind as people who are both tuners and active on here, but I'm sure there are others who might chime in.

This is another shot in the dark here, but on the original tune, did you ask them to enable no lift to shift? The example RPM limit on the "no lift to shift" page on the chromedecu site is 5,000rpm, and says it accomplishes this feature by pulling fuel and spark. Could it be possible that you have a bad clutch switch leaving the ECU to think the clutch is always pressed in and thus leaving NLTS on all the time?

Also can you scroll your scantool to where it shows injector duty cycle and do another video?
 

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..... I also didnt realize there was a fuel filter there ......
It’s not a filter; it’s actually the “fuel tank pressure control valve” that does have an inlet and outlet.
290108

290109
 

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If it was a no lift to shift feature would that cause the 9 counts of knock?
Oh wow I guess I'm completely blind, I didn't even see the knock. Well the knock counts would explain the timing drastic timing change, so I guess there goes that theory. 9 counts of knock just revving in neutral is kind of a lot.

OP: Let's see those injectors duty cycles.
 

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Ok so i just caught up on this thread.

Kink in fuel line - agree its an issue, but IMO it does not explain the problem if you have sufficient fuel to hit boost and drive at WOT below 5000rpm. It takes minimal fuel to rev in neutral. Generally speaking, i just dont think its a fuel supply limitation issue if you can delivery enough fuel to boost under 5k.

Video - the knock at idle is definitely a problem. I watched the video a whole bunch of times including frame by frame. It does look like you get knock and then the ECU immediately pulls timing. Did the tuner put any other kind of falesafes in the tune? Such as fuel cut or something else based on knock? Even with the pulled timing im surprised RPMs dropped even though you were holding/slightly increasing throttle. It definitely seemed like you lost fuel and not just timing.

To me all of this seems like a tune issue...

As far as the injectors go, do you still ahve the 370s in there then? If you have the 370s, and stock MAF, etc, can you swap in a good stock ECU and see if the problem still happens? Stock ECU will work fine with no cats, no EGR/EVAP, etc.

Also, i assume the SAFC was removed when you went chrome?
 

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Discussion Starter #30
I didnt notice the knock until after i posted the video also, facepalm... The SAFC was removed when i went to chrome, also unfortunately i did sell my extra ECU's to 3sx to help afford all the work they did. So swapping the Ecu out isnt feasible right now. I am looking at ordering the tatrix or something to help me datalog tonight. It seems like i really just need to get the car tuned from scratch at this point with someone who knows what they are doing. i have no idea if they put any failsafes in the tune, i doubt they did. I know that they did set my rev limiter to 8000+ trying to get it to rev over 5K. $600+ should get a better tune than what i got, at least i think so.

Rossb- i need to put the car back together to take another video but ill post one when i can. I took the tachometer out and apart, turns out i have a leaking capacitor and a burnt connection on the other capacitor. Im currently trying to find the part number for those so i can replace them. No one near me seems to be able to rebuild it. Thank you so much to everyone helping me, it means alot !!
 

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I took the tachometer out and apart, turns out i have a leaking capacitor and a burnt connection on the other capacitor. Im currently trying to find the part number for those so i can replace them. No one near me seems to be able to rebuild it.
As you can see from first link I posted above, the capacitors are 10 microfarad 25 volt electrolytic radial capacitors (2 of them). When I replaced mine I didn’t remove needle or face plate so as not to affect calibration, there’s room to remove and replace them without removing needle and face, just need to be careful when handling the assembly. If there’s electronic service near you that repairs radios/TV’s etc. they can probably solder in new capacitors for you.
1600094105597.png Click on to image to enlarge
 

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Discussion Starter #35
As you can see from first link I posted above, the capacitors are 10 microfarad 25 volt electrolytic radial capacitors (2 of them). When I replaced mine I didn’t remove needle or face plate so as not to affect calibration, there’s room to remove and replace them without removing needle and face, just need to be careful when handling the assembly. If there’s electronic service near you that repairs radios/TV’s etc. they can probably solder in new capacitors for you.
View attachment 290131 Click on to image to enlarge
Awesome, i just ordered some of those last night. I did take my tach apart so ill have to calibrate it again. Should not be that hard, Famous last words i know right. Thank you white93gt! ill keep you guys posted after i swap them out and if that works or not.
 

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after i swap them out and if that works or not.
Just a reminder (if you don’t already know) capacitors are polarity sensitive, one wire leg is positive and one is negative, they have to go back in same orientation as old ones.
 

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Discussion Starter #37
Alright so where i am at with this issue currently (going off what everyone is saying and my own thoughts) is that it seems to not be only a fuel issue as it happens in neutral also, the car pulls smooth and rich under boost until 5k. Ecu pulls timing and fuel when it gets knock count, you guys seem sure that is a tune issue. Someone mentioned a bad clutch switch is a possibility. (I dont think it is a bad ecu.) Only reason i think that is because it has been happening the entire time ive owned the car, with 3 different stock ECU's and the Chrome ecu.

What to do now- I have the capacitors on order to fix the tach. (According to the Electrical diagram it shouldnt have any affect on the cars performance.)

I am going to pull the fuel pump and try to replace the fuel pump bulk head as it is all bent up and kinked. (also getting to see what kind of pump i have)

I dont know if i should get the tatrix or what to datalog as i already have the '3/S OBD2 touch screen scan tool' it tells me real time information not previous info that a "datalogger" keeps. If anyone has any suggestions that would be great. I want something to read the information that the tuner reads so i can send it to those experts and they can look at and remote tune the car.
 

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Only reason i think that is because it has been happening the entire time ive owned the car, with 3 different stock ECU's and the Chrome ecu.
Whoa whoa whoa, hold up. Am I reading that right, this 5k redline thing has happened with a stock ECU too? If so that rules out the tune idea.

I dont know if i should get the tatrix or what to datalog as i already have the '3/S OBD2 touch screen scan tool' it tells me real time information not previous info that a "datalogger" keeps. If anyone has any suggestions that would be great. I want something to read the information that the tuner reads so i can send it to those experts and they can look at and remote tune the car.
A data logger is exactly what a tuner uses to tune a car on a flashable ECU like the Chromed ECU. You use the tatrix plus something like evoscan or similar, and see information in real time which is then saved to a log to be reviewed later. During a dyno pull the tuner is really only watching for knock and making sure the AFR doesn't go lean. They then use the logs to actually make adjustments to tune the car.
 

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Actually I just re-read your first few posts and this jumped out at me:

have not pulled the fuel pump to tell if it is OEM or not.(i don't think it is hot wired or upgraded)
If your fuel pump isn't hot-wired, or re-wired, I'm gonna out on a limb as say with certainty that your problem is your fuel pump relay/resistor thing. Mitsubishi put this on the cars to try and help not over-run the fuel pressure regulator at idle. When working correctly it limits the voltage to the fuel pump at idle, around 3200rpm it is supposed supply the fuel pump with full voltage to account for boost. If you make too much boost too soon, or the relay is bad, your car will have crazy fuel cut and will fall flat on it's face. What you are describing is exactly what happened to me when I did the "free boost mod" on my stock 1g wastegate solenoid. Around 4000rpm my car would buck like crazy and wouldn't accelerate any further. I did the by-pass and it fixed it instantly.

Here is a link to how to do the bypass. It literally takes 5 minutes, and like $1 worth of parts, so if this happens not to be the fix you haven't lost much. You could also just hot-wire the fuel pump, but that takes a little bit more time and materials.
 

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Whoa whoa whoa, hold up. Am I reading that right, this 5k redline thing has happened with a stock ECU too? If so that rules out the tune idea.
+1 for this - please confirm the 5k issue occured with a stock ECU? That would eliminate the tune.

As far as the fuel pump, i honestly dont think that's it, but doing the bypass/rewire/hotwire could at least rule that out with certainty...

Most importantly though, we need to know if the issue happened on stock ECU.
 
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