Brendo0161 Posted September 23, 2018 Share Posted September 23, 2018 Hi guys, Just looking for some help with my 1993 Supra J-Spec Hardtop N/A Manual. About 4 weeks ago I was out driving and the wires fell out of the plug of my idle air control valve, this caused the engine to rev itself between 1.5k and 3k. Since I reinserted the wires that issue has subsided. However, now the car is running very rich with black smoke and now it won't rev past 4k. At 4k its like its limiter bashing. When it's idle the engine seems to be running very slow just by eye and sits at apparently 1.5k. I haven't been driving it but when I do to troubleshoot it will also surge up and down under load. Things I've tried already: Spark plugs changed and gaped correctly (Correct according to these forums) Changed spark plug leads Soaked O2 sensors in petrol overnight to clean Adjusted TPS as best I could (couldn't get resistance below 1.3) Checked for a vacuum leak Just a guess, but could the wires that came out of the IACV have touched together (they were rubbing against each other) and shorted the ECU or something? Does anyone have any other ideas before I sell my soul to Toyota? Thanks Quote Link to comment Share on other sites More sharing options...
evinX Posted September 23, 2018 Share Posted September 23, 2018 Reset the ECU. Battery off for a while. And make sure the wires are in properly. You can get replacement prewired icv connectors of ebay for a tenner. And the tps is easy to reset with a multimeter...the values change when its in the correct position. Quote Link to comment Share on other sites More sharing options...
j_jza80 Posted September 23, 2018 Share Posted September 23, 2018 Read fault codes Quote Link to comment Share on other sites More sharing options...
Brendo0161 Posted September 23, 2018 Author Share Posted September 23, 2018 Reset the ECU. Battery off for a while. And make sure the wires are in properly. You can get replacement prewired icv connectors of ebay for a tenner. And the tps is easy to reset with a multimeter...the values change when its in the correct position. Unfortunately, i've tried all of this. thanks Quote Link to comment Share on other sites More sharing options...
Brendo0161 Posted September 23, 2018 Author Share Posted September 23, 2018 Read fault codes I do have a check engine light on but I couldn't pull any codes from it because it wasn't flashing. I just read on that link that the immobilizer can interfere with this so I'll try again with it disabled. thanks Quote Link to comment Share on other sites More sharing options...
Brendo0161 Posted October 1, 2018 Author Share Posted October 1, 2018 Just an update for anyone down the road with a similar issue: Took the car to Toyota and they said they couldnt help me because I had an aftermarket fuel pump and tune (I didn't know that). So Ive taken it to PZP tuning in Perth, who specialise in JDM cars. Apparently some circuits on my ecu are fried so they are going to test my car with another ecu to see if that's the issue. Pretty disappointed Toyota didn't pick up on that after 2 hours or working on it. They said it was the first supra they've had in 5 years. If anyone else has this problem I'd recommend saving the headache and just taking it to a specialist. Quote Link to comment Share on other sites More sharing options...
Dave Posted October 7, 2018 Share Posted October 7, 2018 if your ECU is givng you a problem take it to a computer repair specialist let them have a look ,i did this and now mine is working perfect and only cost me 20 pounds Quote Link to comment Share on other sites More sharing options...
Rhodri Evans Posted March 7, 2022 Share Posted March 7, 2022 On 10/1/2018 at 4:56 AM, Brendo0161 said: Just an update for anyone down the road with a similar issue: Took the car to Toyota and they said they couldnt help me because I had an aftermarket fuel pump and tune (I didn't know that). So Ive taken it to PZP tuning in Perth, who specialise in JDM cars. Apparently some circuits on my ecu are fried so they are going to test my car with another ecu to see if that's the issue. Pretty disappointed Toyota didn't pick up on that after 2 hours or working on it. They said it was the first supra they've had in 5 years. If anyone else has this problem I'd recommend saving the headache and just taking it to a specialist. Did this sort the issue? Mine’s doing the exact same thing. Cheers Quote Link to comment Share on other sites More sharing options...
Brendo0161 Posted March 8, 2022 Author Share Posted March 8, 2022 17 hours ago, Rhodri Evans said: Did this sort the issue? Mine’s doing the exact same thing. Cheers Hey, Yeah it turned out to be my ecu. The capacitors perished and leaked out onto the board causing it to short and bug out. I'd recommend pulling your ECU out from the passenger foot well, cracking it open and having a look. Should be fairly obvious if there's anything wrong. Apparently it's pretty common for them to fail around this age so don't make the same mistake as me, don't buy second hand one. I did and it failed too. In the end I got my original ECU professionally refurbished which immediately fixed all the issues i was having. So that's probably your best bet if you're having the same problems. From memory $200-$400 AUD. Could also go full aftermarket ECU set up if you're planning to get into further tuning/performance modding. Obviously that's the more expensive option. Hope this helps 1 Quote Link to comment Share on other sites More sharing options...
Rhodri Evans Posted March 8, 2022 Share Posted March 8, 2022 Alright thanks I’ve had mine repaired before so may send it off again then if that’s the case. Cheers for replying anyway much appreciated Quote Link to comment Share on other sites More sharing options...
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