99 GST with 97 GST ECU fouling plugs

[The Chosen Redneckz]

I have a 99 gst that the ecu was fried in and I bought a new ecu. The car is newer to me but I've had a 98 gs for almost a year now. The new ecu I put in the 99 gst was out of a 97 gst because it was the cheapest one I could get a hold to. It currently isn't on the road so I just drive it around my property every now and then so it doesn't sit but every time I do I have to clean the plugs the next day I go to start it because they are fouled. I checked the oil and it is right at the full line and I turned down the boost some with the boost controlle but continues to do it. I'm starting to think it is the 97 ecu I have in it and I was wondering if anybody knew anything on it. The mods as I know is a full apex exhaust system a aftermarket flywheel and a evo 3 turbo and a stage 3 clutch. That is all the information I have on the car thanks for the help that you can give.

 

[miguelmcv]

What injectors do you have, check the cooling temperature sensor.

 

[The Chosen Redneckz]

What injectors do you have, check the cooling temperature sensor.

The injectors are stock injectors and the cooling temperature rises like it's supposed to to half way when it gets warm.

 

[PlanZero]

97-99 have the same firing order, so I doubt it's the ecu; you sure you're not running rich as a result of a boost leak?

 

[The Chosen Redneckz]

97-99 have the same firing order, so I doubt it's the ecu; you sure you're not running rich as a result of a boost leak?

I honestly have no idea I found threads that said the 97 was 1342 and a 99 was 4123 firing order and i don't know how to check for a boost leak

 

[PlanZero]

Someone correct me if I'm wrong, and to correct myself from earlier, but all 2gs are 4123.
The only time it may be different is when you run a 6 bolt in a 2g or a 1g CAS on a 95-96 ecu since on a 2ga the CAS was inverted behind the cam gear. Alot of DSMers (myself included) with a 97 run a black box (98-99) ecu with no firing problems, so the opposite should be true.
Did you do a thorough boost leak with an air compressor and soapy water? You didn't say you had any other symptoms. I had a boost leak once only under higher rpms, didn't realize because I wasn't ripping around, turned my plugs black every time I ran her.

 

[steve]

97-99 have the same firing order, so I doubt it's the ecu

I honestly have no idea I found threads that said the 97 was 1342 and a 99 was 4123 firing order

Someone correct me if I'm wrong, and to correct myself from earlier, but all 2gs are 4123.

Firing order remains the same for all versions of the 4G63, 1-3-4-2. It's set by design and cast in steel. The order of the wire on the coils isn't the firing order, and depends on the CAS design and location, ECU software, coil pack wiring, as mentioned.

Since the DSM uses a wasted spark, the cylinders are paired 1 and 4, 2 and 3. Switching which wire is on which tower of one coil just changes the polarity of the spark but not when it fires. So you can swap the wires for 1 and 4 or 2 and 3 at the coil without making a difference.

 

[The Chosen Redneckz]

Someone correct me if I'm wrong, and to correct myself from earlier, but all 2gs are 4123.
The only time it may be different is when you run a 6 bolt in a 2g or a 1g CAS on a 95-96 ecu since on a 2ga the CAS was inverted behind the cam gear. Alot of DSMers (myself included) with a 97 run a black box (98-99) ecu with no firing problems, so the opposite should be true.
Did you do a thorough boost leak with an air compressor and soapy water? You didn't say you had any other symptoms. I had a boost leak once only under higher rpms, didn't realize because I wasn't ripping around, turned my plugs black every time I ran her.

I never did a boost Leak test on it but I'll run one and see if I have any leaks and get back to the thread with what I find

 

[The Chosen Redneckz]

Firing order remains the same for all versions of the 4G63, 1-3-4-2. It's set by design and cast in steel. The order of the wire on the coils isn't the firing order, and depends on the CAS design and location, ECU software, coil pack wiring, as mentioned.

Since the DSM uses a wasted spark, the cylinders are paired 1 and 4, 2 and 3. Switching which wire is on which tower of one coil just changes the polarity of the spark but not when it fires. So you can swap the wires for 1 and 4 or 2 and 3 at the coil without making a difference.

I found that I was fouling plugs only when idleing but not when I am driving it on the road because it's finally legal I used over 50$ worth of premium gas in around 80 miles. I pulled the codes and it says the map sensor is bad. It is burning really rich would the map sensot be what causes this? And I also heard there is not map sensor so it might be the maf buy the code I pulled is p0105 and my code app says it's the barometric pressure circulation sensor or the map sensor. Any thoughts?

 

[steve]

There are two sensors, the MAP sensor is on the intake manifold and the Barometric Pressure sensor is part of the MAF. Not being a 2G expert I can't say which the P0105 is complaining about and as you know others posts are misleading on the detail. So I'd inspect and test both.

 

[The Chosen Redneckz]

How do you test them I know how to test the harness but how do you test the sensor