Jas Posted June 21, 2011 Share Posted June 21, 2011 (edited) Hi Guys, Ive developed a problem with my sup. Really need some ideas/advice as its proving way beyond my limited mechanical knowledge. Basically my engine is cutting out intermittently while driving. The Problem Revs will simply drop to zero. Doesn’t seem to be dependent on weather im accelerating, coasting or its just sitting at idle. All the car electronics will stay on (radio dash headlights ect) but the engine will just die. Sometimes the revs will drop to zero and the engine will immediately fire back up of its own accord. So all you feel is a jerk if your driving in a low gear. Other times it will switch off and crank but not start up for a bit. Normally i have to coast to a stop and keep trying it to start before it fires up again… Related Observations. Prior to cutting off there is no hesitation/misfires? Car will be running absolutely fine. Im really stumped. The problem is intermittent and only very occasional. Will happen when car is warm or cold doesn’t seem to make a difference. No error codes are stored on the ECU. Attempted fixes so far So far I have replaced the crank shaft sensor, and major relays (ones I identified as cutting out the engine if there missing!!). But it hasn’t solved the problem. Taking it to my local mechanic tomorrow again but hes pretty much stumped and im having to tell him what to check… im getting him to check the engine earth/ground points next. (good idea?) Correction- had engine ground points, spark plug connectors checked. -still no joy. Any ideas as to what else it could be or what I could get him to check.? Advice/idea would be very much appreciated. Relevant spec/mods? Have RLTC and a greedy Turbo timer installed. Could either of these be causing these symptoms? Would turning the RLTC to the off position allow me to rule out any problems from it or is that not how its works…? My sups a J-spec TT (BPU). And I’ve been avoiding roundabouts like the plague recently!!…. Thanks, Jas. Status. Solved Solution. Scroll further down thread. Edited October 18, 2011 by Jas (see edit history) Quote Link to comment Share on other sites More sharing options...
Guest Mike C Posted June 21, 2011 Share Posted June 21, 2011 Could it be fuel pump or injector related? From the details I'm guessing probably not electrical, although still worth checking the alternator? Quote Link to comment Share on other sites More sharing options...
sammytruck Posted June 21, 2011 Share Posted June 21, 2011 Hi, Certainly new to supras........but on any other car i have had i would guess its fuel related somewhere or other...not much help i know...good luck Quote Link to comment Share on other sites More sharing options...
Jas Posted June 21, 2011 Author Share Posted June 21, 2011 Could it be fuel pump or injector related? From the details I'm guessing probably not electrical, although still worth checking the alternator? Maybe. I would have possibly expected hesitation/spluttering, or misfires with either of these and not a straight cut? You can literally hear the revs needle hit the 0 revs mark as it falls! Quote Link to comment Share on other sites More sharing options...
stevie_b Posted June 21, 2011 Share Posted June 21, 2011 Tricky one, as it's not easily reproducible. I would go back to basics: fuel, air, spark. For fuel, check the fuel filter, pump (if supras have one, I honestly can't remember) and inspect the fuel lines, injectors (as Mike C said). For air, check the air filter although I doubt this will be the cause: it would have to be seriously clogged I would think. For the spark, check the engine block's earth connection(s), inspect or renew the coil packs and spark plugs. Quote Link to comment Share on other sites More sharing options...
Paul Posted June 21, 2011 Share Posted June 21, 2011 I had something like this on a car years ago, not the Supra though, it turned out to be the fuel injection relay. Replaced it and all was good, my mate was an electronics engineer and took it to work and found out that it was due to a couple of pence resistor breaking down and failing when getting warm. Quote Link to comment Share on other sites More sharing options...
welshbuddy Posted June 21, 2011 Share Posted June 21, 2011 My car has been doing exactly the sane thing, all I did wasclean the terminals on the battery, put of grease on the connections, has not happened scince Quote Link to comment Share on other sites More sharing options...
Jas Posted June 21, 2011 Author Share Posted June 21, 2011 (edited) Any one know the best way to illiminate my RLTC as a possible cause? Will removing the RLTC fuse essentially switch off its interferance to the injector signals? hence restoring the car to its pre RLTC state? Or is it active? in a sence that removing the fuse will mean essentially no signals to my injectors. If the latter I guess the only way to illiminate RLTC would be to take the loom wires which have been cut (and reditrected through the RLTC ), and reconnect them to bypass the unit again. Can anyone advise? Terminator, 'where-you-at' buddy - am I making any sence here?? Edited June 21, 2011 by Jas (see edit history) Quote Link to comment Share on other sites More sharing options...
SteveC Posted June 21, 2011 Share Posted June 21, 2011 I don't know how your particular RLTC has been connected/installed, but they can be done with connector plugs so that the RLTC unit can easily be disconnected so the car can be put back to 'normal'. If yours is wired with the plugs, you could eliminate the RLTC fairly quickly. The RLTC is unplugged and the two connectors from the car's main ECU are then connected together - the RLTC is then out of the equation. Quote Link to comment Share on other sites More sharing options...
Jas Posted June 25, 2011 Author Share Posted June 25, 2011 My car has been doing exactly the sane thing, all I did wasclean the terminals on the battery, put of grease on the connections, has not happened scince Do you have rltc on your car by any chance?? Quote Link to comment Share on other sites More sharing options...
TheTurtleshead Posted June 25, 2011 Share Posted June 25, 2011 Sounds like a relay getting hot, check/ swap your EFI relay. I had a 944 that used to do this, changed the relay, no more problems! Quote Link to comment Share on other sites More sharing options...
Jas Posted October 18, 2011 Author Share Posted October 18, 2011 Problem resolved. Solution: Step 1. Locate ageing greddy turbo timer. Step 2. Rip out ageing greddy turbo timer. Step 3. Throw ageing greddy turbo timer on the floor. Step 4. Stamp on it several times while aggressively screaming like a possessed cave man. Step 5. Urinate on it. Step 6: Repeat Step 4. Step 7: Responsibly depose of whats left of it. Step 8: Wash hands and allow heart rate to return to its resting rate. Step 9: Drive and Pull out onto roundabouts with a new sense of confidence. Quote Link to comment Share on other sites More sharing options...
Jas Posted October 18, 2011 Author Share Posted October 18, 2011 (edited) That’s not completely fair to be honest. It could potentially have been either the crank sensor or the timer. Although the car did ‘hiccup’ on a single occasion after the crank sensor was replaced. It hasn’t had any issues since removing the timer. I may reinstall the timer at some point in order to conclusively establish weather it is actually was the source of the problem. Will post findings. God forbid anyone else has such an annoying/worrying problem with there motor, but if it does ever occur to anyone, I hope this thread will go someway in reducing any potential aggravation! Thanks for all the suggestions guys. Much love ‘peeps’. .. . . Edited October 18, 2011 by Jas (see edit history) 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.