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  #16  
Old 03-30-2006, 03:26 PM
dwd1985 dwd1985 is offline
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Quote:
Originally Posted by TomsSVX
owning an mt SVX this is a common occurance. The car simply just stalled out. Just before the stall the lights will come on because the car is reading low voltage(not enough rpms). So basically what you want to firgure out is why the car stalled.

Tom
I trust Tom. If he says it is just a stall, I will take his word for it. Its just weird that it suddenly happened, and then hasnt done it since. Also, I NEVER would have tried disconnecting the battery while the engine is running, I know that is a dumb thing to do. So dont worry guys, that wont be happening.
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  #17  
Old 03-30-2006, 03:49 PM
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Quote:
Originally Posted by dwd1985
Well when I had my alternator replaced 5 months ago, I had the battery replaced with it. It has a 75 month warranty, so im not terribly worried about that. What is interesting to me is that I made the trip from Denver to Fort Collins (about 70 miles), and then from Fort collins to Loveland and back (about 30 miles) and then from my house to school and back (another 4 miles) without any problems. So I have run about 104 miles since the problem, without it showing up again. It is very strange. I just went out and tightened everything battery and alternator wise (even though nothing was really loose). I inspected everything I could, and didnt find any problems anywhere. Pulled the engine codes, none there. So I am at a loss for words...
It appears that you experienced an intermittent fault, the electricians nightmare, because the cause is so difficult to reproduce in order to trace the problem. You will have to keep your fingers crossed and hope that it was a one off.

If it happens again, try to note all the symptoms one by one. Make notes as later it is very difficult to be absolutely positive of the exact original evidence. I suggest this from long experience. Intermittent faults are a real bugger. (Interested to see if that expletive is accepted here. In this part of the world it has appeared without censure in a major TV Toyota advertisement.) *<)
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  #18  
Old 03-30-2006, 04:25 PM
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Confusion

Quote:
Originally Posted by TomsSVX
owning an mt SVX this is a common occurance. The car simply just stalled out. Just before the stall the lights will come on because the car is reading low voltage(not enough rpms). So basically what you want to firgure out is why the car stalled.

Tom
There is no valid reason for several indicator lights to come on as a result of low voltage. Only after the engine has stopped will the lights come on as the test circuit is activated. In any event, if the voltage was low, this would indicate an alternator fault.

However, I agree that the fact that the car stalled, should be taken into the equation. I gather the car was idling at the time. I wonder if the alternator seized, thus imposing an extra sudden load on the engine ? However there are points against this theory. Alternatively a sudden electrical fault imposing a load on the alternator should open the altrnator fuse, unless the wiring has been modified, as has been thoughtlessly recommended here.
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Last edited by Trevor; 03-30-2006 at 04:53 PM. Reason: Typo
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  #19  
Old 03-30-2006, 04:29 PM
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TomsSVX TomsSVX is offline
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Listen, my 6mt comes almost to a stall occasionally and when this happens all the indicator lights come on. THe engine will usually catch itself and rev back up....lights go off. I guess it is the crank/cams sensors not reading rotation quick enough and actually thinking the engine has stopped

Tom
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  #20  
Old 03-30-2006, 05:14 PM
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Quote:
Originally Posted by TomsSVX
Listen, my 6mt comes almost to a stall occasionally and when this happens all the indicator lights come on. THe engine will usually catch itself and rev back up....lights go off. I guess it is the crank/cams sensors not reading rotation quick enough and actually thinking the engine has stopped

Tom
Thanks Tom,

You have now made a good point with this theory. Yes on several counts the engine management system could wrongly assume the engine has stopped, when it has not and initiate the test circuit. I wonder if anyone has found the same occurrence with the SVX?

All in all this is a curly one, with many possibilities. As I said, "a real bugger!"

Cheers, Trevor.
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  #21  
Old 03-31-2006, 06:28 PM
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The season must be bringing the old bugs out. Hi Trevor, I've been on a bit of a sabbatical myself.

I've noticed that on longer, hi speed trips a weak crank sensor will heat soak long enough to not provide an accurate signal. The result will be stalling or surging when returning to idle. Not to be confused with the stalling experienced by the mt converts, I'm still convinced that exists as a lack of proper programming for a manual trans, i.e. no throttle dampening.

Since the car started back up one can rule out alternator and battery probs. If it wasn't charging enough to keep the car running there certainly wouldn't be enough stored energy in the battery to turn the engine over.

Many OEs employ a strategy that won't allow injection pulses until the engine cranks fast enough for the crank sensor (CKP) to generate 500mv. This prevents flooding the engine during cold cycle or weak battery conditions. As CKP sensors age, just like we do, actually, they become more resistant to producing energy. Heat is also a great producer of resistance. I know I dang sure don't work as hard when it's hot outside!

Anyway.... A road trip longer than normal = more heat build-up than normal. An aging CKP, heat-stroking after a long workout, at idle speed, trying to stay above 500mv... If the voltage drops below the threshold the injection pulse shuts down, the engine stalls... you see where I'm going with this.
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  #22  
Old 03-31-2006, 07:50 PM
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The Real Oil

Quote:
Originally Posted by Beav
The season must be bringing the old bugs out. Hi Trevor, I've been on a bit of a sabbatical myself.

I've noticed that on longer, hi speed trips a weak crank sensor will heat soak long enough to not provide an accurate signal. The result will be stalling or surging when returning to idle. Not to be confused with the stalling experienced by the mt converts, I'm still convinced that exists as a lack of proper programming for a manual trans, i.e. no throttle dampening.

Since the car started back up one can rule out alternator and battery probs. If it wasn't charging enough to keep the car running there certainly wouldn't be enough stored energy in the battery to turn the engine over.

Many OEs employ a strategy that won't allow injection pulses until the engine cranks fast enough for the crank sensor (CKP) to generate 500mv. This prevents flooding the engine during cold cycle or weak battery conditions. As CKP sensors age, just like we do, actually, they become more resistant to producing energy. Heat is also a great producer of resistance. I know I dang sure don't work as hard when it's hot outside!

Anyway.... A road trip longer than normal = more heat build-up than normal. An aging CKP, heat-stroking after a long workout, at idle speed, trying to stay above 500mv... If the voltage drops below the threshold the injection pulse shuts down, the engine stalls... you see where I'm going with this.
Special greetings Beav,

As always, on the basis of extensive practical experience, you have come up with the most logical answer.

I have just posted in another thread, using the word "procrastinate", which here now appears to be the order of the day. This, together with the tendency for technical subjects to be continually overlorded by a not always accurate self indulgent individual, has kept me away. I suspect the same applies to you.

Sincere best wishes, Trevor.
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  #23  
Old 03-31-2006, 08:08 PM
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Yes, a great many times the same issues reappear. I would pity the poor horse that endures such a harsh whip, had he survived the first lashing.

When I stroll through the countryside I enjoy the walk. However, I find that as I age I take more frequent breaks during the trip. That way the hills don't seem as steep.
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  #24  
Old 03-31-2006, 08:11 PM
oab_au oab_au is offline
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Crank sensors.

Gid'ay Mate, yes thats whats going on. To add to this, the crank sensor is an inductive/magnetic pickup. The output is dependent on speed, magnetic strength, and the number of turns on the coil.

As they age, the magnet gets weaker, so the output is weaker. Also the magnetic looses strength as it is heated, so the output is weaker.

When we start in the morning the morning the magnetic is cold, so while the speed of the tooth going past, is slow , the output is high enough to fire. As you drive the magnet heats up, the sensors output goes down. So all we need now is for the tooth speed to slow down, and the output is too low to read, the engine stops.

Another time that you get this is, you have been driving, you pull up to buy the news, and the engine won't start. You wait a while. and it starts up OK. The same thing, hot sensor, no output, till it cools.

Harvey.
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  #25  
Old 03-31-2006, 08:20 PM
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spinn360 spinn360 is offline
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SO Ok bad Idea with the batt disconnecting thing. Just was what my dad used to do. But all his cars were old (back before all the computer mess) so I didnt know that could mess things up. Sorry If I was thinking I should have suggested that you test the voltage at the batt with a voltemeter while the car was running. But I wasnt NOT that it matters now.
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Last edited by spinn360; 03-31-2006 at 08:34 PM.
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  #26  
Old 03-31-2006, 10:25 PM
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Friend Beav,

As predicted the lord has donned motarboard. May you now remain, if not lashed, fully informed.

I will join you in your walk, Trevor. *<(

Spin360,

Your thoughtfulness and message will I trust be appreciated.
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  #27  
Old 04-07-2006, 08:04 AM
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I find it interesting that the alternator lamp did not light. I'm currently (pun intended) having a similar problem with my SVX. The abs light comes on, and the car barely starts, but the battery indicator stays off. I checked the voltage from the alternator to the battery and it was only 8.61 volts! As I went thru the trouble shooting procedures outlined in the SVX electrical manual, I end up at "check IC Regulator", not "check alternator". They say that the battery/alternator light should glow when the voltage is below 12, and the alternator is at fault, and conclude that the fault is in the Ignition coil regulator. Now if I only knew where the ignition coil regulator was, I could fix this problem!
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  #28  
Old 04-07-2006, 03:50 PM
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Quote:
Originally Posted by Cappy
I find it interesting that the alternator lamp did not light. I'm currently (pun intended) having a similar problem with my SVX. The abs light comes on, and the car barely starts, but the battery indicator stays off. I checked the voltage from the alternator to the battery and it was only 8.61 volts! As I went thru the trouble shooting procedures outlined in the SVX electrical manual, I end up at "check IC Regulator", not "check alternator". They say that the battery/alternator light should glow when the voltage is below 12, and the alternator is at fault, and conclude that the fault is in the Ignition coil regulator. Now if I only knew where the ignition coil regulator was, I could fix this problem!
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Cappy, so that you are not lead up the garden path, please back track some.

From exactly from where and also when, in respect of engine running, are you reading 8.61 volts ?

What voltage do you read directly from the battery, engine running at say 2,ooo RPM and also wth the ignition turned off ?

A fauly rectifier unit within the alternator is a possible cause. An AC component on line can caurse strange outcomes as a result of blocking diodes being present in circuits.
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Last edited by Trevor; 04-07-2006 at 03:57 PM. Reason: Para added
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  #29  
Old 04-08-2006, 06:49 AM
Cappy Cappy is offline
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Hey Trevor,
I measured the 8.61 volts between the output terminal of the alternator and the negative terminal of the battery, also between the output terminal of the alternator and a ground on the car, plus the output terminal of the alternator and the body of the alternator. All of this was done with the engine running at about 1700RPM's. I also measured 8.61 volts between the battery terminals at 1700RPM's and with the car off. Both were 8.61 volts. I put the battery on a trickle carge overnight, and retested. This time I got 11.98 volts on every test. I haven't driven the car since. I checked all the connections and terminals, including the secondary coils that I could reach. They're all tight.
Thanks,
Cappy
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  #30  
Old 04-09-2006, 08:17 PM
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Quote:
Originally Posted by Cappy
Hey Trevor,
I measured the 8.61 volts between the output terminal of the alternator and the negative terminal of the battery, also between the output terminal of the alternator and a ground on the car, plus the output terminal of the alternator and the body of the alternator. All of this was done with the engine running at about 1700RPM's. I also measured 8.61 volts between the battery terminals at 1700RPM's and with the car off. Both were 8.61 volts. I put the battery on a trickle carge overnight, and retested. This time I got 11.98 volts on every test. I haven't driven the car since. I checked all the connections and terminals, including the secondary coils that I could reach. They're all tight.
Thanks,
Cappy
There appears little doubt that your alternator is faulty. With the engine running at 1,700 RPM you should be registering in excess of 14 votts at all the places you list. All symptoms point in this direction.
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