1G Car dies after start and sometimes doesn't catch up when engine braking

[Gustav093]

I bought my first car back in July this year, it's a 1992 Mitsubishi Eclipse GS and it has randomly started to get worse.

My first problem is that sometimes it starts for a few seconds before it dies (sorry for the wind!) If I try to start the car it just keeps dying and if I wait about 10 - 20 minutes it drives fine.

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).

If I try to accelerate while this is going on the drive belt will start squealing. The clicking in the video sounds like its coming from here (img2), the throttle cable goes from this box.

My second problem is that sometimes when I'm engine braking and push in the clutch to change gears it dies as if it isn't catching up at idle rpm. I don't think that its me who is making the engine go into too low rpms making the engine die.

The last mechanic that worked on the car did something so that the gasket pokes out (img1) but I don't think that is the problem. He also forgot to but back a bolt that was on the cam gear cover.

The exhaust manifold has two screws missing (img1) and sadly the have both been snapped in half and are stuck in the block, it might be leaking exhaust gases from there.

The car is a 1992 Mitsubishi Eclipse GS 1g and doesn't have a OBD port so i cant read the faulty engine codes.

I have checked the resistance in 3 of 4 of the injectors, the first time I checked the two in cylinder 2 and 3 and they read 14,6 then for some reason I only checked the two in cylinder 1 and 2 and they read both read 15 (the fourth one is hard to reach and I don't want to remove the fuel rail).
I still think that the problem is something with the fuel.

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img1

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img2

 

[steve]

On/off half second cycles is the heartbeat indicating normal status.
Next would be to build/buy a 1G datalogger.

 

[We're on Boost]

I found where it tucked behind everything(the pictures really helped), and i tried putting the positive on 1 and negative on 12 but nothing happened but when i switched to negative on 1 and positive on 12 then it dtarted to beep then pause over and over with no diffrence what so ever.

Oh that's awesome! So apparently the connector was still attached and working, although I don't know why it helped to swap the probes around.
Anyway, it sounds like your beeps and pauses are exactly what it's supposed to do in the "Normal State" (it doesn't see anything wrong).

The way it's shown in the trouble code diagrams is like the one at the very bottom of this list (pic below). This scan is from my Haynes manual for 1g Talon/Eclipse. The hand written note is what I found when I tried it. If you can read it.

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[We're on Boost]

I thought there would be a Diagnosis Code number 15 for the ISC. But apparently the 2 liter 1g doesn't have that code. The 1.8 liter does but not the 2 liter. That's how it's shown in the 1991 FSM, the 1990 FSM, and in the Haynes manual.
The 1990 FSM shows the whole code chart on 1 page and has some useful notes, so here that is.
The scan quality is a little funky in some spots, showing horizontal lines in some places where they shouldn't be:

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[Gustav093]

Im sorry to tell yall but i disconnect the battery before working on some other stuff so it probably reset so i have to restart the car and try till it dies again

 

[Gustav093]

The ISC has been replaced but the same issue occurs, I checked the diagnostics and nothing happens on any of them if I put positive on 1 and negative on 12 or any of the others but when I put negative on 1 and positive on 12 or 11 then I still hear the code that says that its running normal but the car died just minutes before checking.

 

[Gustav093]

Next would be to build/buy a 1G datalogger

How would one go about making one by yourself?

 

[We're on Boost]

How would one go about making one by yourself?

Man I don't know!

The best and easiest way I know of, at least for us here in the US, is to send your ECU to ECMTuning for a check over, repair anything wrong with it, and then they modify it with their chip. In other words you'd be buying ECMLink for your car.

It might sound like a horrible process but those guys are really good, and they are not overpriced at all.

Then you need a laptop computer to connect with it in your car. You would use the computer to log drives, and to change any settings you might want to change. It can be an old laptop. Mine is an old Dell that still has WinXP on it and a single core processor!

You are in Sweden?

 

[Gustav093]

Man I don't know!

You are in Sweden?

Yes I live in Sweden and the car is a 92 Eclipse 1g non turbo and shipping doesn't seem to be a big issue.

 

[petrosian]

How would one go about making one by yourself?

I second the datalogger suggestion if it's within your means. Since its a non-turbo, IMO it doesn't make sense to invest in anything more than just a simple logging tool.

I use an old PalmPilot with null serial data cable and the MMC Datalogger (MMCD) app. I have it in a little clip holder attached to my dash just like a cell phone. It has saved me a lot of time diagnosing things over the years.

Some prefer to use a laptop rather than a PalmPilot but that will require a USB to serial port converter or an OLD one with a serial port. It will need software (TunerPro or TMO Datalogger) or a PalmPilot emulator to run MMCD. I'm not sure if ECMLink can be used as just a logger, as I haven't tried it yet (DSMLink you could use it for just logging without having a chip or anything).

One good thing about a simple logger is it's relatively inexpensive, especially if you make your own wires etc. The directions can be found on the MMCD link above. I made my original one back in 2009 but gave it away when I deployed. The one I have now I bought on eBay from Canada (SEE THIS).

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[steve]

The passive interface (unpowered) is simple, just a diode and a resistor. Finding software and getting it running is the trick. This is the schematic I created years ago for the cable back when PC's had serial ports. Since serial ports have two interface flavors (DTE & DCE) you have to get the transmit and receive pins correct for what you're plugging into.
If you use a Palm serial Hotsync cable pins 2 and 3 are reversed compared to this schematic.

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Here's a post using the Palm version.

1G - How to set up MMCD & make a logging cable

***This article is for OBDI DSM's***First thing you should do is get MMCD on your Palm, make sure you are using one of the supported devices from You must be registered to see element. Once you get MMCD on your Palm it's time to make the cable. I used 18 awg wire.Schematic: You must be...

www.dsmtuners.com

Today few PC's have old serial interfaces and instead use a USB serial. Using a FTDI cable makes it easy to connect. Note this uses my same circuit connected to the end of the USB cable.

1G - The Easy Way to Make a 1G USB Datalogging Cable

Making your own USB data logging cable is just as easy, if not easier than making the standard serial cable. It is also more cost effective since the DB-9 serial version would require a USB to RS232 adapter, unless you have a laptop with a serial port. I selected this particular cable because it...

www.dsmtuners.com

There are a few threads on using TunerPro to Log.

1G - How to Log your 1G with Tuner Pro RT

Okay, say you have a nice ECMLink cable sitting in front of you. Or some sort of USB to ODB I cable you have made or picked up and you want to start data logging...You must be registered to see element. is a how to make your own cable that should work just fine with the proper USB drivers...

www.dsmtuners.com

https://www.dsmtuners.com/threads/how-to-basics-of-tunerpro.450153/

We've talked (via the old DSMECU group) to Todd Day and he gave his permission to share the software since Technomotive is defunct. However I don't have a link ATM.

If somebody is a Windows programmer I can provide them with the gory details of how the ODB I stuff works as long as they make the code open source.

 

[dwb]

We've talked (via the old DSMECU group) to Todd Day and he gave his permission to share the software since Technomotive is defunct. However I don't have a link ATM.

I've got a copy of Technomotive (TMO) software. If anyone wants it, PM me and I'll toss it up on google drive. I used it with an old XP laptop with a serial port. Was a great tool for doing diagnostics on my 1g before going with ECMLink.

 

[We're on Boost]

The ISC has been replaced but the same issue occurs

At this point I think it would be a good idea to verify that the ISC system is actually doing what it is supposed to do.
Because even if the new ISC motor is working perfectly, there could still be a problem with the ISC drivers that are in the ECU, and that might not throw a diagnostic code.
So what I would do to test it is pretty simple. Just unbolt the new ISC, take it out, and put it someplace where you can shoot video of it operating while you are in the driver's seat turning the ignition key ON and OFF several times.
Just like in the video I linked to up in post #20.
In that video, be sure to open up the description field and read it so you know exactly what is going on. The description field, YouTube keeps changing stuff but currently what I see on a Windows computer is there is a button that says "...more" which opens up the whole Description.

 

[Gustav093]

At this point I think it would be a good idea to verify that the ISC system is actually doing what it is supposed to do.
Because even if the new ISC motor is working perfectly, there could still be a problem with the ISC drivers that are in the ECU, and that might not throw a diagnostic code.
So what I would do to test it is pretty simple. Just unbolt the new ISC, take it out, and put it someplace where you can shoot video of it operating while you are in the driver's seat turning the ignition key ON and OFF several times.
Just like in the video I linked to up in post #20.
In that video, be sure to open up the description field and read it so you know exactly what is going on. The description field, YouTube keeps changing stuff but currently what I see on a Windows computer is there is a button that says "...more" which opens up the whole Description.

Dont know what to say

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Also saw this

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[petrosian]

Haha! Wasn’t expecting that at the end of the video

Was that plug unplugged? That’s the idle position switch. It tells the car to idle when you let off the throttle.

 

[Gustav093]

Haha! Wasn’t expecting that at the end of the video

Was that plug unplugged? That’s the idle position switch. It tells the car to idle when you let off the throttle.

Yes it was.
The problem could be coming fom that plug since i started the car today and it idled at 1k rpm and was bouncing around +- 1k rpm and when i pressed the throttle it has a hard time catching up when it came down to idle rpm

 

[We're on Boost]

Dont know what to say

Ha! Well .... clearly the ISC was not acting right. It was only extending and never retracting.
It has to retract when you turn the key ON. Then it has to extend when you turn the key OFF.
In your video I hear the key clicks when you turn the key but I can't tell which ones are to ON and which ones are to OFF.
I thought the key click at 0:01 in the video was turning the key to ON but the pintle extended, which is also wrong. It should retract when you turn the key to ON.
I don't know if a disconnected idle position switch would cause it to act this way. I wouldn't think so, but maybe?

If it isn't the idle position switch causing it to act this way, then either there are 1 or more burned out ISC Drivers in your ECU or the new ISC motor was defective or one of the wires in the harness to the ISC has lost connection (corrosion or whatever).
The way I understand the ISC motor is it has 2 field coils in it, one for each direction. Each coil has its own pair of wires from the ECU. If one coil is not operating because it has a bad wire or because its driver in the ECU is burned out, then you would get the thing you got with it only moving in one direction.

I want to post a pic to show you what the ISC driver chips look like in the ECU. I might have to cook one up.
You might be able to tell by looking inside the ECU, looking at these 6 chips. They might be visibly blown up or melted or something. Replacing these driver chips is something ECMtuning can do if you send the ECU to them.

 

[We're on Boost]

ECMtuning has a web page with a picture of some blown up ISC driver chips, and some other good information about the subject. Their pic shows a 2g ecu though, and it's a little hard to see where the chips are in the overall layout. In their pic, the damage is very visible. Not so sure it would always be visible like this.
http://www.ecmtuning.com/wiki/driver01

So here is a shot of an entire 1994 ecu (should be like yours) with the 2 chips marked up that run the ISC motor. The chips in this ecu are good.

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[dwb]

If you or a previous owner haven't replaced the ECU caps, you likely have corrosion on the board resulting in broken traces. Open up your ECU and take a good pic or three. Post it up here and we can usually get a pretty good idea if that's the culprit.

I couldn't help but when that ISC pintle went pop. BTW, the pintle needs to be retracted before it is reinstalled. I think a 6v battery can be used to retract it, assuming the coils are still good.

 

[Gustav093]

the pintle needs to be retracted before it is reinstalled. I think a 6v battery can be used to retract it, assuming the coils are still good.

There are 6 pins which do i need to connect to retract it

 

[dwb]

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[Gustav093]

I have the ECU open and i can see some weird goey substance down to the right and one bent board in the middle, is this bad?

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[dwb]

All three CAPs need to be replaced. This one circled is definitely leaking and you can see the green corrosion around it. There's a circuit trace directly underneath it that controls the ISC that is likely broken. I'd put $$$ on bad CAPS, corrosion, and ultimately broken trace(s) being your problem. The "goey" stuff is a normal coating from the factory and not a problem.

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[steve]

C108 is also leaking and you can see the damage to the SMD capacitors next to it and the one by the MCU.

 

[Gustav093]

Would the best way to fix this to sent it to DSMLink?

 

[dwb]

Would the best way to fix this to sent it to DSMLink?

Yes, very reasonable pricing and quick turnaround. Here's the page you need:

ECMTuning, Inc.