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The mkiv Supra Owners Club

the whole problem story - car won't go over 5100rpm


wilkorangerover

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right this is the whole story i bought this supra twin turbo with a dump valve and apparently 346.2 bhp

I drove the car home fine 200 miles boosted well and drove fine

 

As soon as i had it a few days i swapped the intercooler , because the standard one was shagged, put an induction kit on, and removed the dump valve

 

When i put it together i went down the road and a pipe blew of so i had to drive home steadily and put it back on tight!

 

The car drive s fine for about 15 minutes but after this time when you kick down the car holts revs at 5100 rpM and you hear the second turbo start to spool and then a little dump noise as though the pressure is released , the car will continue to freeze at 5100rpm, 105-110mph and so i have to ease of the pedal and it changes to 4th - then if i kick down two gears hits 5100 and same problem

 

Just changed oil and tranny oil and filters, no change............. HELP PLEASE

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I'm wondering how these cars behave if the crank sensor is loose or shagged, if there was a problem with the crank sensor i reckon it could cause a problem of this nature.

 

Do you know if it's getting full throttle and Slip control throttle isn't interfering with full throttle?

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Don't think any of the things you have done could have caused the problem but worth checking over what you've done to see if you may have accidently upset something in the process.

 

At the least you got a few miles of ok driving before this happened so you shouldn't have too much nightmare getting to the bottom of it. Might take quite a bit of head scratching though mate..:confused:

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Its got an FCD right??? Maybe its fuel cut? Do you have a boost gauge?

 

If it's the fuel cut would he not get the exlamation mark and engine check light warning on the dash and complete shut down of ignition rather than not being to accelerate above 5100rpm?

 

Guess if he has an FCD and it was playing up might be a different story, but don't see how this would stop the rpm at 5100.

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Yes he would get the exclamation mark and engine check light AFAIK Boost run away is a serious issue for the ECU and should put up a warning and an ECU diagnostic code. The fact that the car is doing it in every gear and the fact that it now pops off the intercooler pipework suggests to me he has more boost than he had before swapping out the broken intercooler. That could be just enough to tip a car without an FCD over the edge.

My reasoning behind it being circa 5100 and boost cut would be that it may hit that boost level when max power comes online in and around the 5100 marker, this would happen pretty much regardless of gear selection (maybe other than L).

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I have also heard of the crank position sensor problem but not sure what that is. Just seems odd to coincide with popping off pipes and a change of intercooler. Could a split or slightly holed pipe somewhere in the wastegate line be causing slightly excessive boost (aka like a manual boost control valve) and only now be highlighting itself with a new intercooler?

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As far as iv been told (Adam is on my msn and has been for some time now) it has no decats, no FCD, no boost guage, just an FMIC to replace the broken stock smic (fmic is iirc ebay type)

 

Its running no BOV and will get over 112 mph.

 

Don't see how it would affect rev limit but if he cant find anything obvious but can get over 112mph i assume it has a speedo converter and speed delimeter so may be worth removing the converter put wiring back to stock and see if rev problem is still there perhaps??

 

Still wondering about crank sensor as I encountered a rev limit problem of this nature in the past on a Boxtser which I found to have a loose crank position sensor. Though the rev limit was reduced on that all the time.

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had 15 quid of fuel last time i tried thrashing it

 

£15 of fuel don't last long in a TT Supra if your thrashing it!:D

 

But i doubt its fuel, would maybe idle like a bag of shite and eventually just conk out if there wasn't enough but don't think it would limit your revs.

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i cant under stand it was running perfect..... has anybody run a twin with no BOV like mine now?

 

 

I removed a Blitz Supersound which was on mine when i bought it and fitted an adjustable recirculating jobbie.

 

How is yours now, have you blanked off the open pipes from where you removed the BOV?

 

You could try and source a stock recirc item, sure someone must have one they don't need.

 

I still don't see how this would affect your rev limit, would maybe cause you some boost issues.

Can't you just put your BOV back on just to eliminate that?

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