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1G ECU seems perfect. Car won't start

Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
Hey Guys!

From everything I've seen before, my ECU seems perfect.

In fact I bought a 1g Eclipse with the 4g63 NA with the engine blown. Then bought a new engine and get it inside. The engine worked once, but after the radiator change (seems not related), the MPI fuse blown once and now it doesn't start at all.

Compression is OK in all 4 cylinder.
Spark plugs work fine.
Engine is timed.
Fuel pump is new and working with correct pressure.
CAS is new and the outputs are giving 4x per rotation 5v and 2x per rotation 0.2v (this doesn't seem ok), but injection is working, all 4 injectores look good.

I've been searching for everything but nothing works.

Last chance was to take out the ECU to check if it's good.

The engine worked fine, then started misfiring and working only 1 cylinder, and now won't even start...

Any help?

Thank you all








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Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
Sorry, can't understand.

I've been searching a lot, in this forum also, and many times there is also people speaking about ECU, with this issue.

Did I said something wrong? These photos are to see if someone sees something wrong... I'm not a pro, sorry
 

steve

DSM Wiseman
14,419
1,370
Feb 3, 2002
St. Charles, Illinois
There isn't anything visual that I noticed. Do you have a picture of the cover I'd like to know that the label says since I don't have much data for non-US ECUs.

Does the car do the normal things when you turn the ignition on (CEL on 5 seconds, heart beat on the diag connector, etc.)?
 

Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
Nothing wrong in the pre ignition stage. All lights good. Had error 13 and 25 but because I was with the MAF disconnected, but then connected it, battery off and on, and now doesn't has any error, just a heartbeat.

This is the MD169144 ECU.

I'm afraid that I have something wrong in the harness but I can't find it... Engines rotates, spark plugs work, injectors work... Can't find out the problem
 

enriquez2000

Proven Member
1,679
199
Oct 5, 2014
fort collins, Colorado
Nothing wrong in the pre ignition stage. All lights good. Had error 13 and 25 but because I was with the MAF disconnected, but then connected it, battery off and on, and now doesn't has any error, just a heartbeat.

This is the MD169144 ECU.

I'm afraid that I have something wrong in the harness but I can't find it... Engines rotates, spark plugs work, injectors work... Can't find out the problem
Have you verified that you are getting spark and fuel at the rails? A noid light will tell you if injectors are firing but not if they have fuel.

If you have spark and fuel you should at least stumble.
 

Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
Well, regarding that I have already took out the injection rail with those 3 long bolts, took them out with injector in place and made them fire to some bottles. All of them fired likely the same amount, so I'm guessing they are working (maybe not perfectly), but properly enough for the engine to start...

With spark plugs, I've detached them, get them touching some ground and started the car. All of them are having spark and the gap is also correct.

I think I need to do some live checking everything... Maybe someone comes with something I've never found out...?
 

Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
Are you talking about the one in T with 2 wires? Regarding that, the plug broke, so I have them individually, but I can't confirm if they are in the correct position? Is it possible to confirm which wire to plug in horizontal and which one in vertical? Can't find that information anywhere
 

enriquez2000

Proven Member
1,679
199
Oct 5, 2014
fort collins, Colorado
Just a thought but make sure your Engine Coolant Temp Sensor is connected to the ECU. If the wires are disconnected the car will be difficult to start.
Thats where I was going with the stumbling... it should at least stumble if it has fuel spark air.

Are you talking about the one in T with 2 wires? Regarding that, the plug broke, so I have them individually, but I can't confirm if they are in the correct position? Is it possible to confirm which wire to plug in horizontal and which one in vertical? Can't find that information anywhere
It doesnt matter which is which... they are a resistor circuit.. just make sure they dont have breaks in the wires
 

Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
I will check them, then! Maybe I'll check for continuity from there to the correspondent ECU pin...need to make a search but I think there is a topic where someone specifies which ECU pin goes where
 

enriquez2000

Proven Member
1,679
199
Oct 5, 2014
fort collins, Colorado
I will check them, then! Maybe I'll check for continuity from there to the correspondent ECU pin...need to make a search but I think there is a topic where someone specifies which ECU pin goes where
Pin 20 is the ecu side for coolant temp (91-94). . The other is a ground. I believe pin 24 is sensos ground
 

Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
Sorry, but 91-94? Sorry for newbie things but what does that means?
 

Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
Will check for this tomorrow and I'll advise the results... Maybe I should check for continuity for other cables... Maybe some are being problematic
 

nismojones

Proven Member
117
35
Jan 10, 2008
Eastpointe, Michigan
You have spark and fuel if I’m reading this right. Also you’ve replaced the CAS after it didn’t start? You may have simply installed it 180* out. I’d suggest removing it, spin the input the opposite way and then re-install. If it starts use a timing light to make sure you have it adjusted properly
 

waltah

Proven Member
251
109
Mar 2, 2011
fairfield, Virginia
You have fuel, you have spark, you have compression -- you'd know if you cranked it with too little compression. It must run unless ... unless the spark is at the wrong time. I'm new to the 2g cars so I can't tell you how many ways the spark could be happening at the wrong time but I think Nismoj. probably mentioned the most likely one.

Two sensors tell the ECU when to fire the spark: The cam angle sensor says which cylinder should be fired now (which one's at top dead center of the compression stroke) and the crank angle sensor says exactly when it's there. (The ECU then tweaks that info a few degrees according to operating conditions.) However if the cam angle sensor tells the ECU to fire the wrong cylinder then nothing but nothing is going to happen.

I think the only way that's likely is if the cam angle sensor or some other part of that setup (if that's possible ...) is installed wrong.

On some engines you can get the same effect by scrambling the spark plug wires but I think that would be very hard on a 4g63 with correct length wires. For one thing unless you scramble all of them any cylinder that's wired right will pop when its turn comes. Your engine is dead so they'd have to be all wrong. Say you move the two wires from each coil to the other coil or move the plug wire pair 1-4 to plugs 2-3 and vice-versa.

And of course on some engines with a distributor you can get this situation by getting the rotor on wrong or the distributor shaft in incorrectly.

Anyway this is almost surely just firing the wrong cylinder every time. And it likely won't be that hard to figure out.
 
Last edited:

Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
Hey guys!

So I've finally came near my 1g. Party was too hard on new years eve.
First thing to do was check any harness damages and it seems all is good.

Now I've reinstalled the disc inside the CAS... I'm a bit afraid of backfire but let's see what does it brings to us.

I've also rotated it 180° but it seems not the problem. With it rotated (not timed according the marks), the car sent some popcorns to the admission which is definitely not good. The next step is to turn this on with the disc rotated... We'll see what happens.

You have fuel, you have spark, you have compression -- you'd know if you cranked it with too little compression. It must run unless ... unless the spark is at the wrong time. I'm new to the 2g cars so I can't tell you how many ways the spark could be happening at the wrong time but I think Nismoj. probably mentioned the most likely one.

Two sensors tell the ECU when to fire the spark: The cam angle sensor says which cylinder should be fired now (which one's at top dead center of the compression stroke) and the crank angle sensor says exactly when it's there. (The ECU then tweaks that info a few degrees according to operating conditions.) However if the cam angle sensor tells the ECU to fire the wrong cylinder then nothing but nothing is going to happen.

I think the only way that's likely is if the cam angle sensor or some other part of that setup (if that's possible ...) is installed wrong.

On some engines you can get the same effect by scrambling the spark plug wires but I think that would be very hard on a 4g63 with correct length wires. For one thing unless you scramble all of them any cylinder that's wired right will pop when its turn comes. Your engine is dead so they'd have to be all wrong. Say you move the two wires from each coil to the other coil or move the plug wire pair 1-4 to plugs 2-3 and vice-versa.

And of course on some engines with a distributor you can get this situation by getting the rotor on wrong or the distributor shaft in incorrectly.

Anyway this is almost surely just firing the wrong cylinder every time. And it likely won't be that hard to figure out.
I've already did that, changing the wires from 1-4 to 2-3. It's different from 1g to 2g

On 2g, you have 2 stationary sensors, one at the head and one in the block near the crankshaft poly. I have only one sensor with 2 different signals (you can search for 1g CAS). As this was 900€ on Mitsubishi, I just bought the electronic plate and installed it (I think) not changing the disc direction.

One of my initial thoughts was thinking that this CAS was giving wrong numbers.
With 4 cables, being 1 power and 1 ground, the other 2 should go as 4 times 5v and 2 times 5v but the 4 times 5v is being given but the other gives 2 times 0.2v which I can't confirm if it's ok but I read somewhere that "any value except for 0 is good"

The new CAS is giving the same numbers as the previous one 😂
 

1990TSIAWDTALON

Moderator
9,014
4,890
Nov 14, 2013
Independence, Kansas
Proper setting of the 1g CAS HERE on my channel.
Marty
 

Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
Proper setting of the 1g CAS HERE on my channel.
Marty
Thanks for the additional info! Mine is installed correctly Waha tI want to confirm is the position of the disc inside

Nothing happend but I figured out 2 cylinders (those closer to the timing belt) have their plug soaked and the other two really dry)
 

Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
Guys!!!! WE HAVE A RUNNING ENGINE!! not perfectly but runs.

Still, ECU gives me 3 codes; 12, 13 an 23.
It's a non turbo so 13 doesn't makes me much sense but maybe 12 and 13 always come together because of MAF.

What worries me is 23. The engine runs at 1500rpm but after some seconds turns off.

I've changed the side of the plate inside the CAS, don't know if it is correct but the engine works!

Any idea?
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Last edited by a moderator:

steve

DSM Wiseman
14,419
1,370
Feb 3, 2002
St. Charles, Illinois
12 - Air Flow Sensor
13 - Intake Air Temperature Sensor
23 - Top dead center sensor

If you turned the ECU on while the MAF was disconnected you'll store 12 and 13. Unplug the ECU (or the battery) for a few a seconds and see if those clear.

The other fault is from your CAS. Again if it comes back after a reset it might be time to make cure you didn't break any wires and replace it.
 

Grose1

Proven Member
34
5
Aug 26, 2021
Setúbal, Europe
Well guys... I was without the AC and alternator belts because I took off the timing belt cover. The car worked and I was extremely happy.

After that, without touching any wire I got everything in place. Tried to start the engine and nothing...

Can it be a wire or something? How should I do that? Disconnect everything and search for continuity?
 
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