ST185 swap fuel/air ratio, Getting black smoke from my exhaust Options

[ManpreetS512]

Hey 6GC Members,

I hope you all are doing well.

My name is Manu and I am new to this site, so I apologize if this has been discussed else where and I couldn't find it. If there is already a thread, please point me to it and i'll look it over.

I have a 97 Celica GT with a JDM ST185 swap with JDM ECU. The engine is stock with no modifications thus far. This car was given to me as it sat in a garage for 10 years without ever running. Needless to say, I've gone through a lot of different issues starting with replacing fuel lines, gas tank, fuel pump, cold start injector, etc. to get the motor to crank up again.

The car did not have an exhaust since the previous owner didn't purchase one and mainly wanted to get the swap to run. When we got the motor to crank (finally), it was running really rich. So I took it to a muffler shop and had them add a catback exhaust from the downpipe back with turbo muffler and all 2.5" piping.

Now the car has black smoke coming from the exhaust when it cranks up, so I am assuming that the engine is still getting too much fuel. So friends of mine recommended that I may need a ECU tune but in order to do that I would have to purchase an expensive standalone ECU and then take it to a certified shop and have them tune it.

Before going down that route I wanted to post here to see if anyone has seen similar issues with their swap or this engine in particular? I was also wondering if anyone here knows if the O2 sensor on the downpipe is needed for the ECU to function properly? I ask because when the car was at the muffler shop, I saw the O2 sensor on the downpipe and it was not only rusted but the wire connected to it had been snipped clean - so that O2 sensor in not connected to the wiring harness at all. I also get no check engine light which is odd.

I'm thinking that the O2 sensor on the downpipe does need connection to wiring harness and someone may have snipped it to get the car running before since it had no exhaust. I am not an expert by any means and am learning as I go.

Please let me know if anyone can provide any advice.

Thanks,


Manu

[slavie]

Looking purty. You even retained the AC! You could re-locate the intake to the stock location like the ST205 has, but that ST185 AFM is going to be massively in the way of you doing that.

There isn't an easy way to hook up the wideband, as they require a controller that your stock ECU does not have. You'll need to take a look at the sensor you have to figure out PN or the manufacturer, and get their controller package.

However, given that you don't know the history of the sensor (they don't last forever) and the fact that it's probably older then dinosaur fart, your best bet is to junk it and get a whole new package. There are some new solutions on the market these days that integrate AFR and EBC (electronic boost control) and would make your life overall simpler.

[ManpreetS512]

Looking purty. You even retained the AC! You could re-locate the intake to the stock location like the ST205 has, but that ST185 AFM is going to be massively in the way of you doing that.

Thank you! Yes, AC works but I don't use it since the car sounds like it will die in idle with it on. During idle, RPMs will fluctuate (even with no AC) which I think is a separate issue but may be related. I am also worried that my AFM may be bad and unfortunately, I cannot even read the part number on it to see how much another one will cost

There isn't an easy way to hook up the wideband, as they require a controller that your stock ECU does not have. You'll need to take a look at the sensor you have to figure out PN or the manufacturer, and get their controller package.

However, given that you don't know the history of the sensor (they don't last forever) and the fact that it's probably older then dinosaur fart, your best bet is to junk it and get a whole new package. There are some new solutions on the market these days that integrate AFR and EBC (electronic boost control) and would make your life overall simpler.

This o2 sensor is clearly rusted over. I highly doubt it still works and it is older than dinosaur fart . Do you have a brand or certain system in mind. I wouldn't mind getting one if it wont break the bank.