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| schnoods |
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G'day guys.
I have a problem with my auto xr8 that is bugging me. On take off I floor the pedal into the sump, it goes great (after 15 mins just warm) but it changes from first to 2nd to early. It changes at around 4600 rpm, about 900 rpm shy (and where I am making the most grunt/boost). The problem gets worse when the car is warm (after 30 mins of driving). It wil change at around 4300 rpm. Now I have just recently got the auto rebuilt and beefed up, it still did it before too but with slippage. A couple of questions. 1. What could the culpirit be? I know it could be a range of things, Maybe the tune? Maybe throttle position when opened (havent checked yet), could it be the box? I am not running a XR8 ecu either (v8 fairlane NF) so could maybe that have an effect? Maybe the Capa chip? 2. What would be a way around it other than shifting manually (which is a pain)? It really bugs me, on the dyno chart, it looks to be missing out on 30 odd horsepower shifting early and almost 1 psi (as its a centrifugal blower) with the revs missing up top. Any help would be much appreciated as I'd have some sort of understanding on the situation. Cheers jason.
_________________ Because of Beer, Thirst is a Beautiful Thing! |
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| hans hartman |
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i think ecu has shift points and load mapped,same as fuel maps.
_________________ R.I.P HANS HARTMAN |
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| XH5LWEPN |
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Jas, not sure if the TPS would do it but its definately worth checking them both and setting them to as close to 0.98v as possible without going over.
_________________ STREETBUILT RACING |
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| XR9UTE |
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Sounds like it's trans temp related (TTL pin 34) but could be a number of things.....Do a self test.
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| haggis |
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Don't want to sound like a complete idiot here, but could it just be that the throttle cable has stretched?
_________________ I can see through wooden doors. |
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| schnoods |
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Cheers guys.
Pete, I think it might be temp trans related, as the warmer it gets (at the drags after 3 runs it shifts 300 rpm lower, sometimes more) but would it be a sensor or perhaps it needs a bigger trans cooler (one bigger than a open wallet)? How would you do a self test? Jeff, the TPS has been set at around .98v, but I will check again this weekend, just to make sure. Just in the next couple of weeks I want to change the gears for a better ratio, just dont wanna run out of revs too early before it makes its power. Cheers Jason.
_________________ Because of Beer, Thirst is a Beautiful Thing! |
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| schnoods |
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{USERNAME} wrote: Don't want to sound like a complete idiot here, but could it just be that the throttle cable has stretched?
Throttle cable has been replaced a year ago. 
_________________ Because of Beer, Thirst is a Beautiful Thing! |
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| XR9UTE |
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Yes it could be the actual trans temp sensor or a fault in the TTL line from the TCU to the EEC. The trans TPS is less critical for peformance than the EEC TPS so as long as it's under 1.01V it'll be ok.
Is there anything else it does wrong like in terms of the actual shift speed, downshift timing/speed or converter lock up timing. Is it actually locking up in 3rd and 4th for example? There are plenty of posts about doing a self test....sorry but I'm sick explaining it. Do a trans controller self test first then an EEC self test. Pete. |
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| schnoods |
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Puting you foot down trying to kick down a gear, it can be a tad sluggish to do so, sometimes it is hesitant to as well.
I will look up the self tests tomorrow too, can imagine explaining things a few to many times. I'll see by the weekend hopefully it sorted, not much of a mechanic my self, shame I cant just use a sledge.
_________________ Because of Beer, Thirst is a Beautiful Thing! |
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| WARMACHINE |
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Did you find/fix the problem..
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| schnoods |
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I'll let you know after this weekend.
Hoping its the throttle body not opening completely, giving the tps a 3/4 throttle reding instead of WOT.
_________________ Because of Beer, Thirst is a Beautiful Thing! |
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| badcooky |
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Does the AU have a learning computer?
It may be the S5 wound in too far for your map settings.As the oil gets hotter it gets thinner and the S5 is a pressure regulating solenoid causing it to shift too early,it may even thouugh not often be evil spirits.
_________________ BA XL ute. |
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| SpuDTE |
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What AU is it? AU 1, 2 or 3?
Are the XR8's the same as the T series where you can put the auto in 3 different modes? Econ, Performance or Self Learning? It might have been only the T3's and the Pursuit Utes, but may be worth having a look at your manual. You change it by moving the gear shift around when the car is in Acc (i.e. not started) Just a thought.
_________________ Formerly SpuDEF |
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| schnoods |
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Lol its an EF guys.
The only code that appeared on the self test was the trans temp too high which seemed odd, found a leak in the tranny cooler line and rescanned and nothing appeared which was strange. It now shifts past 5000 (just) and the throttle isnt open completely opening, so thats where my money is at the moment.
_________________ Because of Beer, Thirst is a Beautiful Thing! |
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| SpuDTE |
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Lol, I dont know how I assumes it was an AU
In that case I think your money is safe. I had a problem with my TPS and butterfly opening which gave me all sorts of problems too till I fixed it. Good luck and make sure you keep us updated!
_________________ Formerly SpuDEF |
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