I'm well into my 9th month of a strange problem that is getting drastically worse.
It had echoes of an issue someone posted in the following over on spyderchat a while back: m http://www.spyderchat.com/phpBB/viewtop ... 68#4338168 (http://www.spyderchat.com/phpBB/viewtopic.php?p=4338168#4338168) m and I've hitchhiked on that thread for a while but it's frozen over so I'm here hoping to find some helpful insight.
Without going over the total story, essentially it first manifested when, after driving as normal for a while and being stopped at lights or similar, I go for throttle to take off, the pedal depresses but the engine does NADA!. Of course, one intitally tries another deeper push - still nothing. In panic, you try dropping the SMT into neutral and back into gear, or reverse then back. Intially I found that would work sometimes, or at least it seemed to, and you'd be back to normal.
No warning lights go on, and everything else appears normal. At first it would happen like this, then be fine for days, sometimes weeks. Gradually I got more of it, of course took the 2 to toyota Service as I have twice now, and first time there was an error in the ECU, not anything appropriate to this problem, but they had a good look all over it (according to them - and these guys are all young and into my car), cleared the error and off i go.
Nothing for a day or two but then it's back. Gradually the problem has started happening more often, now when it's running, ie cruising speed, first when changing, usually downshifting 4 to 3rd or 3rd to 2nd, but it's now even happening after a throttle lift.
Some of the people replying to the abovementioned spyderchat thread recommended a loose air filter box cover, and cleaning the MAF, things I've checked and done - the MAF got a surgically-careful clean last sunday, and after an event-free 2 days, the problem is back, and now worse than ever, but still intermittent, and still no warning lights at all.
FWIW I can get normal operation back by holding the throttle pedal flat to the floor for 4 to 6 secs and gradually the engine starts to gain revs and somewhere around 3 to 4000 rpm the pedal/engine connection starts to function properly. I've taken to hitting neutral and checking engine revs while the lights are red, and sometimes it can be fine, then the next time the gear light lights up (indicating the SMT is operating) power is gone gone gone. Of course I'm taking great care to avoid any situations where I'm relying on power to avoid being levelled by large trucks etc.
The guys at Toyota want me to bring it back and leave it with them till they can trace it, since on my second visit to them they were totally stumped - a couple of hours of checking ECU codes and theorising about the thing and they gave up.
I want to do this next week since I can really use the car till then, tho after today its getting so chronic I may just have to hand it over straight away.
I've been told that the SMT relies on several sensors (like the MAF) before it will accept a "GO" scenario, and I didn't even know about the MAF till a month ago so I'm hoping someone out there will have some good ideas.
Anyone able to help?
The throttle pedal only opens the throttle body about 25% - the rest is done using a servo controlled by the SMT ECU. It is this servo that I suspect is faulty.
I would suggest changing the throttle body first, followed by the SMT ECU.
What you really need is a friendly local SMT owner (make sure same mfr year) who will lend you their throttle body and ECU for testing.
HTH
Throttle position sensor?
Put a multimeter across the terminals and measure the resistance. It shoud show a smooth increase or decrease in resistance as you turn the sensor. If theres any spikes in the reading, showing very high resistance/ open circuit., or a short circuit anywhere in the movement, you need a new one...
Quote from: "GSB"Throttle position sensor?
Put a multimeter across the terminals and measure the resistance. It shoud show a smooth increase or decrease in resistance as you turn the sensor. If theres any spikes in the reading, showing very high resistance/ open circuit., or a short circuit anywhere in the movement, you need a new one...
This is where things could get interesting - the TPS is operated by the butterfly spindle, which is in turn operated (in part) by the SMT servo.
IIRC from the few bits of the wiring diagram that I have seen, the TPS connects to the engine ECU but not the SMT ECU.
If it were a dodgy TPS, I would expect the engine to splutter when the throttle is opened rapidly as the ECU would not increase the fueling correctly.
The reason I suspect the SMT throttle servo is there is no mention of the engine spluttering - simply it doesnt respond to the throttle pedal at all. If the throttle is held open, then eventually the throttle butterfly does open and the revs rise. This would suggest to me either a bent throttle butterfly shaft that is causing it to stick in the (semi) closed position, or the servo unit may have stripped a gear.
There isnt (AFAIK) a sensor on the throttle pedal itself, as I was able to rev the engine by operating the cam on the throttle body which doesnt move the pedal itself, and there are no other sensors on the throttle body.
It's strange that there should be a rash of smt problems suddenly, too many to be conincidence surely... There must be an inherant fault somewhere along the line, and I would've said that it's been the cold conditions of late (as my own problem is worse on cold mornings/evenings) but I'm guessing fairly hot in australia!! s:wink: :wink: s:wink:
Quote from: "SteveJ"Quote from: "GSB"Throttle position sensor?
Put a multimeter across the terminals and measure the resistance. <<<X>>>> in the movement, you need a new one...
If it were a dodgy TPS................................
The reason I suspect the SMT throttle servo is there is no mention of the engine spluttering - simply it doesnt respond to the throttle pedal at all. If the throttle is held open, then eventually the throttle butterfly does open and the revs rise. This would suggest to me either a bent throttle butterfly shaft that is causing it to stick in the (semi) closed position, or the servo unit may have stripped a gear.
No, there's no engine splutter, and in fact, what IS curious about this, even in the light of these possibilities, is that once I get normal throttle back, everything appears absolutely fine. I've even had this on trackdays (tho curiously only one small incident in each of three t/days in this time), and as long as this doesn't occur I'm puttng in good times and there's no dodginess in the throttle action. - and whats even more scarey here is that my Driving Force Pro wheel and pedals occassionally do something similar - actually it's the brake sensor dropping some braking force unaided into the car whilst in GT4!! but i digress...
Thanks lads, I have one buddy with an 03 and it's SMT (since we get NO choice of a manual vsn here in Aust. s:x :x s:x ) and perhaps some pleading with him will get me some test parts.
I have a couple of SMT ECU's so I may be able to help out. What year is your car?
Have you actually thought about the throttle cable? or spring on the accelerater pedal?
I had a fault with the cable i'm using. At the pedal end there is a small plastic clip that simply slides onto a recess at the top of the pedal. It is only held in place by pressure from the spring.
If there is no engine change and toyota can't spot it then I guess it could be a failure of this kind.
Quote from: "Jap GT300"I have a couple of SMT ECU's so I may be able to help out. What year is your car?
Have you actually thought about the throttle cable? or spring on the accelerater pedal?
If there is no engine change and toyota can't spot it then I guess it could be a failure of this kind.
mine is an 03. re: ECU, thanks! any help would be muchly appreciated, but since i'm in Sydney Aust, let me try the throttle cable, spring and a full look at the throttle body etc (which I haven't done fully yet). Perhaps then I'll let Yota do their magic ( s:wink: :wink: s:wink: ) and then if they can't fix it, then I'll get into ECU/throttle body swaps.
I'll try to make some time early tmrw morning (your evening) to scope the cable and throttle etc.
Cheers and thanks for the help so far ppl
ahhhh... can anyone tell me where the throttle body IS - and what it looks like please? I've snooped and searched web and mr2roc and can't find anything.
Interestingly, have cleaned and played with the pedal end and said problem hasn't been as common.
jury still out of course.
Quote from: "Tamajamma"where the throttle body IS - and what it looks like please?
It's connected to the intake manifold and looks like this:
(http://www.spydermagazine.com/files/sasthrottlebody.jpg)
Quote from: "Tem"[
It's connected to the intake manifold and looks like this:
xcellent, thanks Tem
Hi Tama nice to see there's an MRS frequenting Sydney. I've only seen 1 in 10 days so far. I'm over in Kirribilli and carless but I may go back to MR ownership s8) 8) s8)
Quote from: "Comer"I'm over in Kirribilli and carless but I may go back to MR ownership s8) 8) s8)
see, you may sell up and go half way round the world but you'll always come back to the fold s:wink: :wink: s:wink:
Quote from: "Comer"Hi Tama nice to see there's an MRS frequenting Sydney. I've only seen 1 in 10 days so far. I'm over in Kirribilli and carless but I may go back to MR ownership s8) 8) s8)
Hey Comer, there's not many 2 drivers here; Toyota didn't try very hard. And only offer(ed) the SMT after the 5speed manual but that's a whole other story.
( m http://www.spyderchat.com/phpBB/viewtop ... 88#4326588 (http://www.spyderchat.com/phpBB/viewtopic.php?p=4326588#4326588) m )
There's a few of us around though... smug and smooth in the twisty bits. Come back to the dark side. you won't regret it.
Yeah, my Spyder did the same thing every summer and I had found out by experimenting, that when you open your driver side door and dont start the car afterwards, this problem will happen. I had found this out by opening the driver side door and closing it after I got my cd's from the car. The next day when I was about to go to work, it had worked fine in the beginning then all of a sudden the car engine would stall and the accelerator wouldnt give.
Also, it has nothing to do with the battery or anything else, the dealer always had to replace the ECU chip, then it had worked perfectly again. I am surprised their were no recalls yet for this problem. Probably because their were not that many complaints. I believe everyone should open the driverside door just to get the sequential pump working then close the door afterwards and start the car few hours later or the next day. Then everyone will have to go to the dealer, and it will have a recall. I believe the problem is that the ECU chip need to be revised differently. Because the chip thinks that the next time the door has open it has to pressure again but the pressure was already there the first time.