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  #16  
Old 05-02-2007, 11:27 PM
jeffast jeffast is offline
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thanks that makes sense
i'll let you know how it goes tommorow
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  #17  
Old 05-02-2007, 11:30 PM
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  #18  
Old 05-04-2007, 03:47 PM
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not the tps, any more guess's?





i'm getting fed up with this car
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  #19  
Old 05-04-2007, 05:01 PM
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Quote:
Originally Posted by jeffast
not the tps, any more guess's?





i'm getting fed up with this car

Now calm down Jeff.....for what you gave for the car, did you expect it to be perfect from the start?
Anything that's been run down from it previous owner will take some time to get all lined out...but will be worth it in the end.

If it's getting to you, just step away from it for a while...work on the XT6 for a bit...everything goes better when you don't rush it.


Just some advise from an old timer....
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  #20  
Old 05-04-2007, 10:18 PM
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Quote:
Originally Posted by huck369
Now calm down Jeff.....for what you gave for the car, did you expect it to be perfect from the start?
Anything that's been run down from it previous owner will take some time to get all lined out...but will be worth it in the end.

If it's getting to you, just step away from it for a while...work on the XT6 for a bit...everything goes better when you don't rush it.


Just some advise from an old timer....
ok
any way any more guesses as to whats causing it?
and it's not just the car,
i have a really bad head ache, and have been somewhat bed ridden when not working on the car or at work for the past three or four days, so sorry i'm just a little grouchy
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  #21  
Old 05-05-2007, 07:55 PM
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Umm...

Any codes...power light flasing when you start the car? Does it just shift beteen gears, or is it a big *clunk* when it does it?
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  #22  
Old 05-05-2007, 08:57 PM
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Quote:
Originally Posted by kis86
Any codes...power light flasing when you start the car? Does it just shift beteen gears, or is it a big *clunk* when it does it?
i believe it may have a code i'll go check, and it just keeps endlessly shifting like it's confused abotu what gear is right
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Last edited by jeffast; 05-05-2007 at 09:03 PM.
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  #23  
Old 05-05-2007, 09:05 PM
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how do i pull tcu codes i can't find it under the how to section?
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  #24  
Old 05-06-2007, 07:03 AM
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Quote:
Originally Posted by jeffast
how do i pull tcu codes i can't find it under the how to section?

After you pull the codes, How Too Check Tans Codes
you might need to tighten the "brake band" (instructions here:Brake Band adjustment )
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  #25  
Old 05-06-2007, 07:50 AM
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Hey one thing to check...when the ATF gets to a certain temperature, it will allow 4th gear, but before that it will not. I remember back when I lived where there was winter, that my SVX would do this on the highway sometimes when it was really cold out.

It would drop out into 3rd for a while, then the fluid would warm up again, and back into 4th for a while until it cooled off again, then repeat the whole thing...
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  #26  
Old 05-06-2007, 09:03 PM
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Quote:
Originally Posted by huck369
After you pull the codes, How Too Check Tans Codes
you might need to tighten the "brake band" (instructions here:Brake Band adjustment )
well good news, i read the write up and the brake band symptoms do not at all match the problems i'm haveign i have anouther theory i'm gonna eather test tommorow or the next day... i'll keep you posted,
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  #27  
Old 05-07-2007, 05:05 AM
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Quote:
Originally Posted by jeffast
well good news, i read the write up and the brake band symptoms do not at all match the problems i'm haveign i have anouther theory i'm gonna eather test tommorow or the next day... i'll keep you posted,
Jeff

Testing for the TPS is the first port of call with the symptoms you describe. Mainly because it is easy to check, and it has a lot of bearing on how the gearbox behaves.

The gearbox computer [TCU] uses a number of signals as inputs. It uses these to decide when and how shifts happen. The principal ones it requires to "decide" are road speed and throttle position [TPS]

If it can't see a signal for road speed, it will throw a code, which is why you need to check the codes.

Regards the TPS, there are more than one areas than can create faulty behaviour. First and easiest to check is the set voltage, the one you have already done. It should be 0.50V, 0.52V is good also.

However, the software in the TCU not only needs the TPS to be set in the proper range. It needs the signal from it to be linear. It decides to change down based on the speed of voltage change. If there is a damaged spot, a gap, in the rheostat wires that the sweeper moves across, this can send unsteady and conflicting voltages to the TCU at that point. This confuses the computer, and may cause the jumping in and out of gear you mention.

So because you have set the TPS to the correct range [and it is very sensitive to that!!] does not mean that your TPS is OK or perfect. You could still have a faulty [non-linear] TPS, and you need to check there are no damage "gaps" inside it.

If there are gaps, if the signal is not even or linear, you will need to change it. Obviously be sure this is your problem before buying a new one. These things cost over a hundred bucks, but smooth and accurate signal from this little black box is critical for the gearbox.

I hope that helps and does not confuse.

Joe
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  #28  
Old 05-08-2007, 12:48 AM
jeffast jeffast is offline
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Quote:
Originally Posted by svxistentialist
Jeff

and you need to check there are no damage "gaps" inside it.

If there are gaps, if the signal is not even or linear, you will need to change it. Obviously be sure this is your problem before buying a new one. These things cost over a hundred bucks, but smooth and accurate signal from this little black box is critical for the gearbox.

I hope that helps and does not confuse.

Joe
i checked it off the car, it was almost perfect there was one gap where it jumped .4 ohms, aside from that it accelerated evenly across the whole range of motion with a normal gap of .2 ohms is that big enough to make a huge differance?
also, i drove it today and it seemed to do fine with no problems what so ever, so now i'm confused, i'll report more when i have driven it on the freeway for a while
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  #29  
Old 05-08-2007, 06:17 AM
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Joe has given you a good run down on the basics but there is something which requires clarification.

Unfortunately, a bygone, know all, alleged engineer, some time ago posted in very certain terms, incorrect information regarding the construction ot the TPS. It most certainly is not wire wound, or a simple form of rheostat or potentiometer.

The TPS comprises two resistive plastic elements working in tandem, bridged with a rotary wiping contact. If a broken wire wound element was involved, you would have been unable to measure voltage in the idle position, as a voltage divider arrangement is involved.

However, what you report does indicate intermittent contact and a fault which could very well be causing problems as Joe has indicated. Dirt or lack of contact pressure could be the reason.

The how too info. has become rather confused and I would suggest that you check my locker for data and tips on testing and cleaning the TPS.

Some time ago at my suggestion, a member cut a faulty unit open and investigated its construction. It appears certain that even though the unit is manufactured as non repairable, with ingenuity, it could be stripped, properly cleaned, adjusted and restored. However the first person to attempt this, should certainly have a spare on hand as a back up.
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  #30  
Old 05-09-2007, 11:32 PM
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don't worry i just had a bad tps in my xt6, i'm gonna go to the local u pullit they had 2 last time i was there
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