herbiemercman Posted July 9, 2022 Share Posted July 9, 2022 I had this problem several months back and now it has returned. Everything on the engine sensors and all the ignition components have been replaced. Today i went for a short drive and the original problem reapeared, miss firing,black smoke, over fueling. I gave the car some boot and it went OK, fast and smooth, when i slowed down the problem reapeared, i limped home on just two cylinders. I let the engine cool for 5 hrs and then restarted her, it was perfect. What components can fail when they are hot? and why have they not failed over the past few weeks? I have a Toyota OEM. ECU with an "Emanage Blue" piggy back, in their location in the inside of the cars foot well they don't get warm, so i think they can just fail at random? Are the ECU's still available and who in the UK can sort this out? Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted July 9, 2022 Share Posted July 9, 2022 Ignition components are notorious for failing when hot. Hight temperature means high resistance in electrical components Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted July 10, 2022 Author Share Posted July 10, 2022 Hi Swampy, The whole of the HT ignition system was replace when this problem first started, coil, spark plugs, leads, knock sensor. The problem could be the MAP sensor or the throttle plenum air temp sensor. I just hope it is not the Emange Blue piggy back, or the Toyota ECU, they are 25 yrs old and 60K miles. The coolant water temperature sensor that feeds the ECU was changed at the same time. The biggest problem of all is the intermittancy, 4 months back when the problem started all i did was cleaned the plug pins on the piggy back, and disconnect the battery for 40 secs to remove the fault curves, then for the past 12 weeks she has run perfectly and very fast, the full 452 BHP on the dyno. Following the return of the problem yesterday, misfiring,sick with fuel, black smoke, and running on just two cylinders, i booted the throttle and it shot off, as normal, when i slowed down the problem returned. When i took it home on two cylinders and let it stand for 5 hrs i just turned the key and it was back to superb running, cruising smooth, and very fast. This a very difficult problem to solve and i am now involved with a friend of mine Chris Wilson, who repaired my brother's Supra 8 yrs back, no one else in the country could fix it, he had to replace the Toyota OEM, ECU, the over fueling was so bad, it sooted up the engine. Quote Link to comment Share on other sites More sharing options...
Big Supes Posted July 10, 2022 Share Posted July 10, 2022 What model of Supra do you have and what modifications? Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted July 10, 2022 Share Posted July 10, 2022 Can you datalog from the emanage blue? You could from the ultimate. It could also be a failing ECU Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted July 10, 2022 Author Share Posted July 10, 2022 2 hours ago, Big Supes said: What model of Supra do you have and what modifications? Hi Supes, it is a 1995 mk4 with the 2jzge engine, it was was tuned in 2015 by "Rocket Dog Racing" in Cardiff. single GT.70/68. T4 turbo, "Emanage Blue" piggy back ECU, closed loop, std Toyota ECU. Mapped by a top guy, friend of Craig Attard, the owner of his tuning company, it was 452 BHP. I owned the car from new and it has only done 60K miles, and 8 miles since the conversion. Chris Wilson is a friend of mine and we are trying to find out what is causing the intermitent over fueling and misfiring on some cylinders. We are now looking into the MAP sensor, the crankshaft sensor, but Rocket Dog says this model, 2jzge does not have one? the distributer does the same job.The main concern for me is can the problem be the piggy back or the Toyota's ECU. Everything is great for a few weeks, then the problem raises its head again, very difficult to find what is wrong? Do you know any experts as Chris can be unavailable. Quote Link to comment Share on other sites More sharing options...
evinX Posted July 10, 2022 Share Posted July 10, 2022 Check the air sensor on the bulkhead nearer to the passenger side. Has a nipple coming off it with a vaccum hose going to the inlet manifold. If they break they can cause those symptoms Quote Link to comment Share on other sites More sharing options...
Big Supes Posted July 10, 2022 Share Posted July 10, 2022 2 hours ago, herbiemercman said: Hi Supes, it is a 1995 mk4 with the 2jzge engine, it was was tuned in 2015 by "Rocket Dog Racing" in Cardiff. single GT.70/68. T4 turbo, "Emanage Blue" piggy back ECU, closed loop, std Toyota ECU. Mapped by a top guy, friend of Craig Attard, the owner of his tuning company, it was 452 BHP. I owned the car from new and it has only done 60K miles, and 8 miles since the conversion. Chris Wilson is a friend of mine and we are trying to find out what is causing the intermitent over fueling and misfiring on some cylinders. We are now looking into the MAP sensor, the crankshaft sensor, but Rocket Dog says this model, 2jzge does not have one? the distributer does the same job.The main concern for me is can the problem be the piggy back or the Toyota's ECU. Everything is great for a few weeks, then the problem raises its head again, very difficult to find what is wrong? Do you know any experts as Chris can be unavailable. Outside of checking for vaccum leaks, it sounds a bit like one of those, change 'this and that' and hope you get lucky, scenarios. I'm not very versed in the GE or NA-T's, but I'd imagine it would have a MAP sensor, but sure, the dizzy is driven by the camshaft so the timing is mechanical. Tbh, if Chris Wilson is on the case, I don't think I can offer anything outside of his knowledge. I presume the ignition system is in good order, especially the HT leads? I recall them shorting onto the cylinder head when they break down over time. Quote Link to comment Share on other sites More sharing options...
Style Posted July 11, 2022 Share Posted July 11, 2022 Have you swapped out any of the distributor components at all? Might be the the distributor cap and rotor arm could do with being refreshed. If it's overfuelling, then it sounds like a spark issue and if it's missing on 4 cylinders it could be distributor based. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.