2G EU GS 4G63 NT running insanely rich

[Parkos]

Recently my best friend gifted me a 1996 Eclipse GS 4G63 NT he found for sale very cheap while traveling.
The reason for being cheap is that the engine is extremely unsteady. With a rough idle (Even stalling if not stepping into the gas) and a strong gas smell (and with strong I mean that being near the car is completely uncomfortable).

I have checked for error codes but it doesnit throw any and the CEL is off. Checked MAF and TPS. Coils, cables and spark plugs are new and the O2 sensors seems to work fine.
No vacuum leaks found and compression values are correct.

I have also checked values through diagnosis and the mechanic told me that the injectors are too many time open (5 - 5.5ms) in idle. Sometimes, when the car is revved it spits some kind of semi-liquid black mess through the exhaust.

I did also an emissions test which gives the "small" amount of 1000 ppm HC.
The car is completely stock, no mods.

Any ideas?
Thanks!

PS: Sorry if i misspell something wrong. English is not my main language xD

 

[pauleyman]

Recently my best friend gifted me a 1996 Eclipse GS 4G63 NT he found for sale very cheap while traveling.
The reason for being cheap is that the engine is extremely unsteady. With a rough idle (Even stalling if not stepping into the gas) and a strong gas smell (and with strong I mean that being near the car is completely uncomfortable).

I have checked for error codes but it doesnit throw any and the CEL is off. Checked MAF and TPS. Coils, cables and spark plugs are new and the O2 sensors seems to work fine.
No vacuum leaks found and compression values are correct.

I have also checked values through diagnosis and the mechanic told me that the injectors are too many time open (5 - 5.5ms) in idle. Sometimes, when the car is revved it spits some kind of semi-liquid black mess through the exhaust.

I did also an emissions test which gives the "small" amount of 1000 ppm HC.
The car is completely stock, no mods.

Any ideas?
Thanks!

PS: Sorry if i misspell something wrong. English is not my main language xD

Are you 100% sure nothing has been changed? Is everything plugged in? What have you already checked?

 

[danl]

If you are getting 5+ ms of injector pulse width at idle then something is telling the ECU to add more fuel. The MAF could be reading incorrectly, the coolant temperature sensor could be bad or a wire broken. The intake air temp sensor could be bad. Have him scan the MAF hertz, coolant temp, TPS, IAT, and barometric or MAP sensors to see if any of them are reading high.

A scan tool for under $100 can do this for you and is worth having.

 

[Parkos]

Updates on my DSM:
Checked the timing belt, everything is ok.
The O2 sensor (my 4g63 is NA and only has 1) seemed to be misreading sometimes so I replaced It as well as the ECT because it leaked a bit.

With the new O2 and ECT it runs slightly better.
Still rough idle and a bit high rpm but not as hard as before. The car still running rich but not even close at It was before (I have to make a new emission test to measure the difference). Now you can still smell it but it doesn't choke you.
Before the new ECT and O2 it was nearly impossible to be around the car after 1 minute of running.

BTW I'm gonna buy the Haynes manual to have the values i should get on the sensors and harness to make some more checks.

So making advances :3

 

[steve]

The quality of the Haynes manuals isn't the best. Try downloading and looking at https://www.mediafire.com/file/uz7nqzs13z55j6k/2g_eclipse_FSM_European_market.zip/file

 

[danl]

If your car was running that rich for long enough, you need to change the oil as it is likely diluted with gas. Verify the ECT sensor is reading correctly with a logger. The wiring to the sensor could be bad and you “fixed” the issue when moving the wires when replacing the sensor.

 

[Parkos]

The quality of the Haynes manuals isn't the best. Try downloading and looking at https://www.mediafire.com/file/uz7nqzs13z55j6k/2g_eclipse_FSM_European_market.zip/file

Thank you!

If your car was running that rich for long enough, you need to change the oil as it is likely diluted with gas. Verify the ECT sensor is reading correctly with a logger. The wiring to the sensor could be bad and you “fixed” the issue when moving the wires when replacing the sensor.

This weekend im gonna check the full harness to be sure but i already put a new ECT. Changing the oil is on the check list for whenever its repaired as right now im not driving it except 100m of taking it in and out of the workshops in weekends.

 

[Parkos]

Today I was able to work on the car:
IAC and TPS changed, also regulated correctly the new TPS. Also found a damaged wire on the TPS harness and repaired it. The old IAC came out completely destroyed, so the stepped motor was working correctly but wasn't moving the pin.
The idle is a bit high but stable at 1k rpm. Adjusted the BISS but still high even when fully close.

Now I have found the it sometimes stalls at random moments and still running a bit rich. Gonna check the Knock sensor and the MAF again.

 

[Parkos]

New updates:

I'm now on the DSM demential train. I have changed the MAF, so now it hesitates a bit on the idle and the CEL came on, but it has stopped to randomly stall.

As I was going nuts with the CEL the 2G decided to concede me my wish about it, in a twisted way: Now I don't have the MIL light on, neither the RPM nor the speedometer are working, so it seems like the instrument cluster is, as the Germans say: Kaputt.

Still running a bit rich.

 

[Parkos]

I'm back guys!
I've been working on the DSM so I have some updates:

The CEL was on due to the MAF not being compatible with the OEM reference I gave them, so I ordered a new one from Rockauto which turned it off and made the RPM stable.

The instrument cluster started working again the next day I posted about it failing and hasn't failed since then.
The car still running rich and you can smell the gas odor if you are close to the exhaust, but i will say is like an 80% less than how it was at the beginning.

But as the DSM won't let me rest now that I have stable RPM I was able to see that while it is idling if I step in the clutch the RPM raises about 300-400 rpm.
Also if I'm driving in 4th gear it will randomly spit it out to neutral.

The never ending DSM project adventure.

EDIT: After the 1st test drive over 100 km/h i think i have found the source of the problem that make it run rich. Whenever i stepped on the gas over 2000 rpm i noticed w whistle sound coming from the engine. So it seems like it has some kind of vacuum leak.

 

[Parkos]

So there are good news and bad news:
The good ones, found some leaks on the vacuum lines, so they were replaced.

The bad news is that i feel like im again at the starting point. Tthe car suddenly started to rough iddle while, and after every time i accelerated the rpm went down and the car stalled.
I parked it and made a selfdiagnose with the CEL light (As no OBD or datalogger has been able to read codes) and i got a 25, 14 and 44 codes.
I havent been able to teel what they stand for exactly because they differ by manuals, 14 is for MAP/VCI in one and for TPS in other. 25 for IAC in one and Barometric sensor in other, and 44 for Battery Temperature/PCm in one and VCI/Ignition coil in other.

My car, as i said in the 1st post is a 2G 4G63 NA (EU market) with no mods, so it doesnt have MAP, Baro and neither Bat Temperautre sensor.

The IAC made sense to me, as I replaced the one it had with a new one and in started working fine, but the new one was from AliExpress so it wasnt strange if it broke in a month. But today i changed it for a good quality one, but still the same.

Any idea?

 

[miliman13]

So there are good news and bad news:
The good ones, found some leaks on the vacuum lines, so they were replaced.

The bad news is that i feel like im again at the starting point. Tthe car suddenly started to rough iddle while, and after every time i accelerated the rpm went down and the car stalled.
I parked it and made a selfdiagnose with the CEL light (As no OBD or datalogger has been able to read codes) and i got a 25, 14 and 44 codes.
I havent been able to teel what they stand for exactly because they differ by manuals, 14 is for MAP/VCI in one and for TPS in other. 25 for IAC in one and Barometric sensor in other, and 44 for Battery Temperature/PCm in one and VCI/Ignition coil in other.

My car, as i said in the 1st post is a 2G 4G63 NA (EU market) with no mods, so it doesnt have MAP, Baro and neither Bat Temperautre sensor.

The IAC made sense to me, as I replaced the one it had with a new one and in started working fine, but the new one was from AliExpress so it wasnt strange if it broke in a month. But today i changed it for a good quality one, but still the same.

Any idea?

Great car !! wish we had that option vs the rs/gs

It's good to use codes to lead you in the correct direction, check your sensors using a multimeter, I'm sure there's major differences in the EU version but most ECU's and their sensors run and read at 5v & (0-5v) so this can help, you can always use a microcontroller to log some of these sensor values, if you don't have something more sophisticated.

Reading and capturing values have for me been the major form i have been able to diagnose and resolve many issues. When I ran rich it was for many reasons like a bad sensor and a stuck injector.
You have to spend time testing diffrent componenets of the system, just like you have.

 

[steve]

i got a 25, 14 and 44 codes.
I havent been able to teel what they stand for exactly because they differ by manuals, 14 is for MAP/VCI in one and for TPS in other. 25 for IAC in one and Barometric sensor in other, and 44 for Battery Temperature/PCm in one and VCI/Ignition coil in other.

What's the ECU part number?

Given what you worked on in the past I'm inclined to think 14 = TPS, 25 = Baro, 44 = Coil or Power Transistor like what is in my 2g Euro manual.

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The Baro sensor is part of the factory MAF.

The TPS looks like it's a standard 2G TPS with the embedded IPS

 

[Parkos]

What's the ECU part number?

Given what you worked on in the past I'm inclined to think 14 = TPS, 25 = Baro, 44 = Coil or Power Transistor like what is in my 2g Euro manual.

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The Baro sensor is part of the factory MAF.

The TPS looks like it's a standard 2G TPS with the embedded IPS

BTW Yesterday i took the out the IAC from aliexpress and put the new one (Holstein from Rockauto). It was already planned as i dont trust aliexpress for engine parts.
The CEL turned off but still it runs like before.

The TPS (UltraPower) and the MAF (Delphi) are both new and have less than a month. I still dont have rpm nor speed signal in the cluster, so im starting to think that there is some kind of electric golbin in the car or the ECU is fried.

 

[steve]

RPM would be from the Power Transistor. There is a test connector in the engine bay and from there it runs to the ECU, maybe the ETACS, and to the gauge cluster.

Speedometer uses the VSS signal. That starts out as a pull up voltage from the ECU that the sensor in the transmission grounds as the wheels turn creating pulses. It goes to several places besides the ECU and Cluster. You'll have to check the manuals since I haven't chased it on a 2G EU DSM. I had to on a 3000GT and it went to the ETACS, Cruise Control computer, and ABS if I recall correctly. In that case I found water had gotten into of of the connectors and shorted the pins.

The TPS fault can be caused by both a bad sensor and by it's adjustment being off. If it comes back I'd make sure it is set correctly before replacing it.

I would like to get the ECU numbers and a picture of the circuit board, if you could, to update my list.

 

[Parkos]

RPM would be from the Power Transistor. There is a test connector in the engine bay and from there it runs to the ECU, maybe the ETACS, and to the gauge cluster.

Speedometer uses the VSS signal. That starts out as a pull up voltage from the ECU that the sensor in the transmission grounds as the wheels turn creating pulses. It goes to several places besides the ECU and Cluster. You'll have to check the manuals since I haven't chased it on a 2G EU DSM. I had to on a 3000GT and it went to the ETACS, Cruise Control computer, and ABS if I recall correctly. In that case I found water had gotten into of of the connectors and shorted the pins.

The TPS fault can be caused by both a bad sensor and by it's adjustment being off. If it comes back I'd make sure it is set correctly before replacing it.

I would like to get the ECU numbers and a picture of the circuit board, if you could, to update my list.

Gonna check the TPS and if its correctly adjusted tomorrow. Next weekend i will try to take out the ECU to check the pins and connector, so i will take a photo for you ^^

 

[Parkos]

Hi hi my fellow DSM friends!

I'm back with updates. I haven't been able to take out the ECU as I've been working double turns but i replaced the ICM with the new one.

Now the car runs again, but now again is running rich and the idle is a bit unstable. Gonna buy a pair of new coils as the one it has seems like they haven't been replaced in a long long time. Also i still have to adjust the TPS bcs y think most of the idle problems are coming from there. Any advice for getting the V easy out of the pins?

Also the idea of some wiring failing is getting stronger. As today after the ICM replace the speedometer was working but not the RPM and then after some driving and stops they started working again. Where does it takes the RPM signal from? Is it from the CKP or I am wrong?

 

[Parkos]

Hi everyone! Im back after some time with big happy news!

Today finally it stopped sounding like a rotary, the idle is nearly full stable (A variation of less than 100rpm) and is only running a bit rich.
I tried to get some info using evoscan with a tactrix cable but was unable to connect to the ECU.

Anyway. Lets go to the point of what has been driving me completly crazy:
By removing the upper cover od the timing belt i though that the timing was done correctly. Obv i was wrong. I bought a new CKP and after dissasembling everything i found that except for the camshafts was not timed correctly. The source of the problems? Not of all of them, because the CKP was nearly obliterated and hanging by thread of copper.

After that it started to work better but still sounding like rotary and running rich. Thanks to some wd40 i found the throttle body was the problem, and with new seals on the shaft, the biss and a new gasket i was able to do the correct adjustment of the biss and now. Finally This little nightmare sounds right and is only runing a bit rich, wich i assume its because of the O2 sensor, as i've read lot of ppl in the EU who had problems with Bosch O2 sensors that stopped after changing it to Denso one.

 

[chrysler kid]

The tactrix cable will only work on the black box 1998-99 or evo8 ecu or non turbo 00-06 eclipse ecu

Are you sure the firing order is set correctly from the ignition coils, verify previous owner didn’t accidentally mess up cylinders when connecting wires

Tps calibration is needed, using a volt meter into the plug I was able to see voltage readings without special tools

 

[Parkos]

The tactrix cable will only work on the black box 1998-99 or evo8 ecu or non turbo 00-06 eclipse ecu

Are you sure the firing order is set correctly from the ignition coils, verify previous owner didn’t accidentally mess up cylinders when connecting wires

Tps calibration is needed, using a volt meter into the plug I was able to see voltage readings without special tools

Ye, firing order was corrected some months ago (It was incorrect) i changed aswell the spark wires because previous owner put some random NGK (Now i have the correct blue NGK)
I calibrated the TPS with a volt meter with clamps and 2 needles to stuck them in the connector xD