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Misfiring on boost?

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Hey guys,


I've been running my GTT on Caltex 98, and just yesterday switched to BP Ultimate (there was about 1/3rd fuel left in the tank).


It was running fine before that, now today when I started it up it felt a bit funny, drove it up a few streets, pushed my foot a little further and it felt like I had no power. Turbo spools etc. So I went onto the highway, planted my foot in 4th, felt like there was no boost (boost gauge wasn't moving either, but the turbo was spooling). I was like uh oh, so I drove to an empty street, dropped it into second and floored it, I heard a few pops, of what I would say sounded like misfires coming from the engine, with still no power (this was at 4k~ or so rpm, so when the boost would kick in). Almost stalled at the lights taking off..


I drove around steadily for another 10 minutes or so and then all of a sudden everything was fine, drove around for another 30 minutes and I swear it was even smoother than before.


My question is.. Is this because I mixed the two fuels? Or something more sinister? I have heard rumors that the Caltex 98 isn't actually 98.. So could this f**k with timings or something?


Edited by thenixtone

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Caltex 98 is not really 98, it is more like 96 with some black magic added that they claim makes it work like 98 but it isn't really true.  I wouldn't put it in my lawnmower.

BP98 is usually the best quality choice around.

Mixing the fuels shouldn't do anything, especially with the bulk of it being BP.

There are such things as occasional bad batches.  Has happened to me.  But that wouldn't go away in 10 minutes - would last the whole tank.

Your experience might suggest a blocked injector, which may have possibly been caused by different detergent additives in the BP fuel releasing stuff that the Caltex was not moving - but only a small blockage that cleared itself.  Which would be unusual.

The symptoms sound like ignition misfiring also, so it could be worth pondering the state of your coils.

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Probably shit fuel (e.g. water in fuel tank at the servo).

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