Clausz Posted May 3, 2015 Share Posted May 3, 2015 Hi everyone After 2 years of rebuilding my supra, I have an slight issue. The engine won't rev above 3000 rpm, it seems like a limp mode or something like that. After a complete engine rebuild, new internal, new turbo, new intake, new injectors and so on. None of which shouldn't be relevant to the fault I'm experiencing. It started by, I though it was due to the upgrade from 720cc low impedance to 1000cc high impedance. I went to my local tuner, experienced supra tuner, and after 1 hour of rechecking the map and further faults in the box he called me, and meant that the injectors was defect(or at least not giving fuel as 1000cc should). Wen revving the car hits 3000rpm and the lambda gauge goes lean (>22). I brought the car back and at first changed the injectors to 720cc, but no changes. I made some videoes: https://youtu.be/keZmox4NDjQ - engine revving and "limping" around 3000rpm. https://youtu.be/WHOHz0z63mE - lambda guage going lean. What I have already checked: Checked the HKS FCON for sensor faults = No one found Checked the Stock ECU for sensor faults = Found two knock sensors wasn't connected, fixed but no change. Checked voltage on injectors = 14,3-14,6volts Put ground on igniter module = no change Put ground on Resister box = no change Checked timing, 15-17 degrees in idle I made two other findings, which I find strange. 1: When I pull the plug to the ECU water temp sensor, the engine is running a lot nicer and idles better. But still have the max 3000rpm issue. 2: If I start it immediately and rev it, it goes above 3000rpm, and then suddenly drops to 3000rpm. Please see video: https://youtu.be/rcY2tVbpBUs So here is the complete list of things changed during the rebuild: New internals Changed from a aftermarket intake manifold to stock intake Removed TRAC Removed ABS Moved fuse box to the rear compartment New turbo Anyone who has some great ideas of what to look for next? I'm loosing my courage with this issue. Best Regards Claus Quote Link to comment Share on other sites More sharing options...
rider Posted May 3, 2015 Share Posted May 3, 2015 There may be some daylight in this Prelude restricted revs on a new build thread. http://www.preludeonline.com/f60/rebuilt-engine-will-not-rev-past-3000-rpm-s-238501/ Goes on about a throttle sensor fault. Quote Link to comment Share on other sites More sharing options...
Clausz Posted May 4, 2015 Author Share Posted May 4, 2015 The tuner adjusted the TPS sensor, it was only 4% open, when he adjusted it. But I can try changing it, to see if it's broken when opening more than 20% for example. Thanks I will try that. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 4, 2015 Share Posted May 4, 2015 Have you got the software to read sensors via the HKS ecu? Without having your own HKS ECU software you will find diagnosing this sort of thing near impossible if the fault is encoding in the ecu. My tip is NEVER EVER buy an ecu that does not come with full control software if you intend any hands on engine work yourself. Can you even go as far as pulling a log from it to send to your mapper? Quote Link to comment Share on other sites More sharing options...
Clausz Posted May 4, 2015 Author Share Posted May 4, 2015 Hi Chris, I do agree. The car was bought with a HKS installed, and I therefore had no intentions of changing that, as it actually worked a couple of years ago. If I had the choice right now, I wouldn't fit a new HKS, there are so many other options. I arranged with the mapper, that I will take the car out to him on thursday, and he will start faultfinding. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 4, 2015 Share Posted May 4, 2015 I feel for you, these problems, when you have an after market ECU, leave you wondering if it's the ECU or an engine sensor fault. Once you can access the software for the ECU and read the sensors as the *ECU* is reading them, helps immensely. The HKS ECU is very competent for an old(ish) school one, but if o0nly the mapper can read data it's very limiting. An end user who just wants a map, and is happy to enjoy things, and just take it back to a garage with the software if things go wrong will not notice the difference, but if you are a "tinkerer" and like changing stuff, the lack of access to software is a *MAJOR* limitation. I hope you get it sorted soon, it's probably something quite simple to fix, once you find the problem. Quote Link to comment Share on other sites More sharing options...
Clausz Posted May 9, 2015 Author Share Posted May 9, 2015 I delivered the car to the tuner for him to do the faultfindings. I will keep you updated. Quote Link to comment Share on other sites More sharing options...
Clausz Posted May 14, 2015 Author Share Posted May 14, 2015 Chris, you were right. It was actually pretty simple. I had installed a TRC sensor instead of the TPS sensor. The car is now working. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 14, 2015 Share Posted May 14, 2015 That would definitely not work Glad it *WAS* a simple fix, all the best Clausz Quote Link to comment Share on other sites More sharing options...
Clausz Posted May 14, 2015 Author Share Posted May 14, 2015 I need to get me myself a powerwriter software:D Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 14, 2015 Share Posted May 14, 2015 Pity HKS don't even offer a READ ONLY software.... To end users. Quote Link to comment Share on other sites More sharing options...
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