drift_bear Posted August 31, 2015 Share Posted August 31, 2015 Coming back up the road on Saturday after picking up the supra, i stopped at a service station for the usual food/toilet break. After returning to the car to leave, i went to start the car and nothing! It cranked over fine and tried to start but just wouldn't do it, so after a couple of hours i managed to get the car started with the use of a booster pack, from a passing AA van. That was all fine and well untill about 40 miles later, i had to stop for fuel and guess what.....it happened again but this time there was no passing AA vans to help I let the car cool down, changed the map and it started eventually after a few cranks. Yesterday after leaving the car overnight, i went out and took the car out a long run and then hooked up the laptop to see what syvecs was saying and to see if anything was happening. While i was doing this i was speaking to Lee and he said i should be watching the crank and it should read 360 - 720 - Run, instead i was getting 360 - Turn - Stop so it indicated i wasn't getting full crank on start up. I had always planned to change to a stronger battery so i done that today and its still doing it, i will try and add the video and the small graph from the syvecs and hopefully help understand the problem im trying to describe lol https://vimeo.com/137847077 Has anyone any idea what to check? I am thinking the crank sensor could be on its way out Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 31, 2015 Share Posted August 31, 2015 LOG the cam and crank sensor outputs, and send them to Syvecs to see what they think, you need to get them in digital form in a log, and the X axis needs expanding in order to see more detail (faster time per division). If it were my Motec I'd e-mail the log to Oz or the US office, as they will be open and it's not a Bank Holiday... I'd probably have an answer in an hour or two. Quote Link to comment Share on other sites More sharing options...
drift_bear Posted August 31, 2015 Author Share Posted August 31, 2015 LOG the cam and crank sensor outputs, and send them to Syvecs to see what they think, you need to get them in digital form in a log, and the X axis needs expanding in order to see more detail (faster time per division). If it were my Motec I'd e-mail the log to Oz or the US office, as they will be open and it's not a Bank Holiday... I'd probably have an answer in an hour or two. I will try and get time tonight to pull the specific logs and see what i find. Untill then any other options of stuff to check would be handy Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 31, 2015 Share Posted August 31, 2015 (edited) In my experience connectors are FAR more likely to give trouble than sealed sensors like cam and crank. A fairly cheap USB oscilloscope would be a good tool if you like tinkering with this sort of thing. In relative terms all automotive "stuff" occurs slowly, so you don't need a fast scope, a 50 MHz one should be more than good enough. Perhaps a second hand. elderly Picosope, which is automotive friendly in that it will set itself up for common measurements. I would also ensure the ecu was getting all its 12V supplies whilst cranking, and it's not an ignition switch issue. From memory I think you will need to tell the Syvecs just what to log, and in what depth. I find the software a nightmare though Make sure logging starts before cranking.... Edited August 31, 2015 by Chris Wilson (see edit history) Quote Link to comment Share on other sites More sharing options...
T2 MSW Posted September 1, 2015 Share Posted September 1, 2015 As Chris said you need to increase the frequency you log at up to 10Khz. I had this exact same issue and it was my cam sensor as the Syvecs was getting a very very weak signal. Again as Chris has said it wasn't the cam sensor itself but the connector even though I replaced both at the same time. And before anyone says it my car only has one Cam sensor and I think the base maps only have one input configured for the Syvecs anyway. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 1, 2015 Share Posted September 1, 2015 You could just try disconnecting the (remote, on the end of a wire moulded into the crank sensor, and direct onto the one cam sensor used) sensor connectors, spraying them with contact cleaner, examining for damage, and re-connecting them. It might fix a bad connection... Quote Link to comment Share on other sites More sharing options...
Guest suprageek Posted September 1, 2015 Share Posted September 1, 2015 Check your coolant temp sensor plug as mine was doing the same thing and the wires going into the plug were cracked Quote Link to comment Share on other sites More sharing options...
Scott Posted September 1, 2015 Share Posted September 1, 2015 The lower coolant sensor on the rad causes this issue as above. It had me perplexed for AGES. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 1, 2015 Share Posted September 1, 2015 Surely that's just used as a fan switch, even if used with an aftermarket ECU? In the Syvecs software check ALL sensors are giving sensible readings! Actuate the throttle and see the readings rise and fall with no glitches or dead spots, especially around idle and cruise throttle positions, where the sensor gets the most wear. Quote Link to comment Share on other sites More sharing options...
drift_bear Posted September 1, 2015 Author Share Posted September 1, 2015 I have ordered new crank position sensor, cam position sensor and water temp sensor from Mr T, I would rather have them and not need them than need them and not have them! Sunday will be my next day off, so i will be working on the car then and checking logs/data from syvecs Quote Link to comment Share on other sites More sharing options...
Scott Posted September 1, 2015 Share Posted September 1, 2015 Surely that's just used as a fan switch, even if used with an aftermarket ECU? In the Syvecs software check ALL sensors are giving sensible readings! Actuate the throttle and see the readings rise and fall with no glitches or dead spots, especially around idle and cruise throttle positions, where the sensor gets the most wear. You would think so Chris but my car was just bpu at the time. One of the pins wasn't in right and my car wouldn't fire at all. Pushed it in and bingo, worked first turn. Quote Link to comment Share on other sites More sharing options...
a98pmalcolm Posted September 1, 2015 Share Posted September 1, 2015 i have a similar issue. let me know how u get on. With me i need to add a little throttle to get it started Quote Link to comment Share on other sites More sharing options...
drift_bear Posted October 8, 2015 Author Share Posted October 8, 2015 (edited) A quick update to this... I still have the issue and have now changed/cleaned the following parts and the problem is still there :- Crank position sensor - New Cam position sensor - New Coolant temp sensor - New Stronger Battery - New Igniter - Known working one Coilpack clips - All ok Coilpack's - All cleaned and ok Spark plugs - New Earth points - All cleaned and ok Battery terminals - All cleaned, tightened and ok I have a new fuel pump due tomorrow, other coilpacks and a new starter motor to fit and try that after reading up various threads on supraforums regarding this problem! I'm hoping that this will cure my problem once and for all. I have spoke to Lee and he thinks it is a crank issue due to the battery dropping volts while cranking, but surely there is nothing else i can change for the crank related parts **edit** The lower coolant sensor on the rad causes this issue as above. It had me perplexed for AGES. I seemed to have missed this, will check the connectors for this sensor while i do the starter motor! Edited October 8, 2015 by drift_bear (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 8, 2015 Share Posted October 8, 2015 Just measure the battery voltage whilst cranking, sheer madness throwing parts at it willy nilly, what exactly are the scope graphs supposed to be showing, and can you post ones with the time axis expanded? Quote Link to comment Share on other sites More sharing options...
drift_bear Posted October 8, 2015 Author Share Posted October 8, 2015 Just measure the battery voltage whilst cranking, sheer madness throwing parts at it willy nilly, what exactly are the scope graphs supposed to be showing, and can you post ones with the time axis expanded? Here's s quick video showing the voltage of the battery on crank https://vimeo.com/141791254 I've not been out in the car for a few days, the weather has been rubbish and not for a supra Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 8, 2015 Share Posted October 8, 2015 What happens if you jump it off another running car? Quote Link to comment Share on other sites More sharing options...
drift_bear Posted October 8, 2015 Author Share Posted October 8, 2015 What happens if you jump it off another running car? I used a booster pack before and it fired up eventually. Never had another car to jump it from Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 8, 2015 Share Posted October 8, 2015 Is it using the stock TT igniter? If so, find the ground wire to the igniter on pin 4, splice into it, and connect the spliced in wire direct to a clean and shiny engine ground and see if it helps. It's vital the igniter has a good ground as it switches a lot of current. Quote Link to comment Share on other sites More sharing options...
drift_bear Posted October 8, 2015 Author Share Posted October 8, 2015 I just plugged the laptop up to syvecs and got the car to temp, switched it off and went to turn it back on and check what happens....And it seems to have stopped playing up? I went over the cam sensor plugs and coolant temp sensor plug with electrical contact cleaner (since I got a new tin of it) Is it using the stock TT igniter? If so, find the ground wire to the igniter on pin 4, splice into it, and connect the spliced in wire direct to a clean and shiny engine ground and see if it helps. It's vital the igniter has a good ground as it switches a lot of current. Yeah it's still using the stock TT igniter chris.. What colour will it be? How do I work out which one is pin 4? I'm assuming you mean the main big connector? Quote Link to comment Share on other sites More sharing options...
Scott Posted October 8, 2015 Share Posted October 8, 2015 Coolant temp sensor plug ftw Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 8, 2015 Share Posted October 8, 2015 I just plugged the laptop up to syvecs and got the car to temp, switched it off and went to turn it back on and check what happens....And it seems to have stopped playing up? I went over the cam sensor plugs and coolant temp sensor plug with electrical contact cleaner (since I got a new tin of it) Yeah it's still using the stock TT igniter chris.. What colour will it be? How do I work out which one is pin 4? I'm assuming you mean the main big connector? I would imagine it will show the pin outs in the service manual, or Google it. I would expect (note *EXPECT*) pin one to be on the left looking into the socket of the igniter. Quote Link to comment Share on other sites More sharing options...
drift_bear Posted October 8, 2015 Author Share Posted October 8, 2015 Coolant temp sensor plug ftw Is that your thought Scott? I would imagine it will show the pin outs in the service manual, or Google it. I would expect (note *EXPECT*) pin one to be on the left looking into the socket of the igniter. Never thought about checking the workshop manual I've left it for 10mins to simulate getting fuel, will see how it gets on once I try start it again Quote Link to comment Share on other sites More sharing options...
Scott Posted October 8, 2015 Share Posted October 8, 2015 Has been since I posted on the 1st of last month I've experienced it, it was a nightmare to track down. Although mine wouldn't start at all, not just when hot. It playing up could simply be to do with the contacts expanding/contracting during heating and cooling. I just simply forgot to plug the fecker in Quote Link to comment Share on other sites More sharing options...
drift_bear Posted October 8, 2015 Author Share Posted October 8, 2015 Has been since I posted on the 1st of last month I've experienced it, it was a nightmare to track down. Although mine wouldn't start at all, not just when hot. It playing up could simply be to do with the contacts expanding/contracting during heating and cooling. I just simply forgot to plug the fecker in If your referring to the lower sensor, I never touched that lol Quote Link to comment Share on other sites More sharing options...
Scott Posted October 8, 2015 Share Posted October 8, 2015 If your referring to the lower sensor, I never touched that lol Ahh, doubt it'll be the upper one then. Try disconnecting it and see if it causes any issues Quote Link to comment Share on other sites More sharing options...
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