[mkiv] Lost substantial amount of power

Mon Oct 22 09:25:52 CDT 2007

Honestly I cant really believe ambient temperature alone makes such a huge 
difference.
As I said, I noticed powerloss on hot days before (and noticing a power gain 
at night), but it was never that bad. And I also thought it was mostly 
because of my clogged up intercooler (which got changed now).
It really drives me insane to see less power with a not-clogged-up 
intercooler.

So I really dont know what to do. I didnt reset the ECU, so its not that. 
Low octane fuel is not the problem either. I dont see overheating either. 
Oil temps are fine.
I even tried running with the stock air box again, because I thought my air 
filter is sucking too much warm air. Didnt help either.

Youre talking about a Methanol/Water injection? How do those work?

Jake
94TT 6SPD

----- Original Message ----- 
From: "John Cribb" <johnacribb at yahoo.com>
To: "'The MKIV.com National Mailing List'" <mkiv at mkiv.com>
Sent: Monday, 22 October, 2007 14:14
Subject: RE: [mkiv] Lost substantial amount of power

> Jake, if you're sure it's only the ambient temperature change that was
> responsible for the power increase, then you might want to consider a M/W
> injection kit to keep your intake air temps down.
>
> Other things that could have affected the power are retarded timing due to
> low octane fuel or overheating - perhaps with your other work you've reset
> the ECU and it's starting over again with fresh learned settings?
>
> But it's true, our motors definitely like the cool weather better than the
> hot.
>
> John
> '97 APU
> '94 BPU
>
> -----Original Message-----
> From: mkiv-bounces at mkiv.com [mailto:mkiv-bounces at mkiv.com] On Behalf Of 
> Jake
> Sent: Monday, October 22, 2007 5:38 AM
> To: The MKIV.com National Mailing List
> Subject: Re: [mkiv] Lost substantial amount of power
>
>
> Alright, I think I found the cause for power loss on my Supra. As someone
> already suggested, its the ambient temperature, how wierd it may
> sound.
> I was normally driving at 77 to 86F when I had low power, but yesterday I
> drove at about 42-50F. The difference was HUGE. The car pulled like mad
> again, so that I actually got a little scared at times, since I wasnt used
> to so much power anymore. I would guess it was at least 30-40 HP more than
> before.
> Ive had my car for 8 years now, and also noticed power loss on very hot
> weater before, but it was never this bad.
>
> Now, I changed my stock intercooler just before I got that power loss,
> because my old one was completely clogged up with insects, dirt, etc. I
> bought a used one, which still looked very good. So actually I should have
> much less problems with high intake temperature.
> But why is it worse now? :(
>
> Is it really normal to lose so much power to ambient temperature? What can 
> I
>
> do to counter it?
> A FMIC would be the last option for me, since I would have to get a custom
> one done due to the european active spoiler taking up space.
>
> Thanks
>
> Jake
> 94TT 6SPD
>
> ----- Original Message ----- 
> From: "George Datuashvili" <gdatuashvili at gmail.com>
> To: "The MKIV.com National Mailing List" <mkiv at mkiv.com>
> Sent: Saturday, 15 September, 2007 21:16
> Subject: Re: [mkiv] Lost substantial amount of power
>
>
>> I don't think it's old cat.
>> When was the lat time you changed the fuel filter?
>>
>> Some more ideas:
>> - spark plugs
>> - coil packs
>> - bad fuel pump
>> - bad fuel (try different gas station & brand)
>> - boost leak (where exactly is your sensor mounted that shows 1.1bar?)
>> - conspiracy theory (porschas you raced have more power than owners
>> disclosed)
>>
>>
>>
>> On 9/15/07, Jake <JakeGrafton at gmx.de> wrote:
>>>
>>> Hi guys,
>>> it looks like my Supra has lost quite some power recently. I didnt
>>> really notice it until I was only dead-even with several 325 HP
>>> Porsches. I should have owned them bad.
>>> Now, the turbos are boosting fine, the engine runs smooth, is not even
>>> burning much oil and everything else seems to be in order. I am running
>>> 1.1 bar with the stock cats installed right now. But I was able to beat
>>> Porsches like that before with this setup.
>>> So what could be the problem? I heard it could be either caused by a
>>> dirty
>>> fuel filter, a bad MAF or a defective cat. Is that true?
>>> All 3 possibilities could very well be the cause. In the last few weeks 
>>> I
>>> have been running my car very, very often with low fuel. That could mean
>>> a
>>> dirty fuel filter, IIRC.
>>>
>>> I have also used a Blitz SUS air filter, which wasnt cleaning the air
>>> very
>>> good (there was slight dirt inside the intake pipes, so the MAF could be
>>> faulty from all this dirt.
>>>
>>> And last but not least my cat is very old. It has seen lots of use
>>> and high EGTs so it could also be that its defective, also because my
>>> EGCV failed a few months ago (it got replaced a few weeks before I
>>> noticed the loss in power).
>>>
>>> The question now is, how do I test the MAF for normal function? Where
>>> is the fuel filter located and how do I see if its dirty or not?
>>>
>>> Anyone know any other possible causes that could steal me like 30-60
>>> HP?
>>>
>>> Thanks a lot in advance!
>>>
>>> Jake
>>> 94TT
>>> _______________________________________________
>>> Mkiv mailing list
>>> Mkiv at mkiv.com
>>> http://www.mkiv.com/mailman/listinfo/mkiv
>>>
>> _______________________________________________
>> Mkiv mailing list
>> Mkiv at mkiv.com
>> http://www.mkiv.com/mailman/listinfo/mkiv
>
> _______________________________________________
> Mkiv mailing list
> Mkiv at mkiv.com
> http://www.mkiv.com/mailman/listinfo/mkiv
>
>
> _______________________________________________
> Mkiv mailing list
> Mkiv at mkiv.com
> http://www.mkiv.com/mailman/listinfo/mkiv 