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The mkiv Supra Owners Club

NA-T misfire or revving problem


FOSTA

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my car: toyota supra 1993 jap import mkiv, non turbo, automatic. just fitted an xs-power T-61 turbo kit. so its now NA-T.

 

everything it totally stock, Head gasket, injectors and so on...

 

running:

T-61 XS-POWER TURBO KIT

. E-MANAGE ULTAMATE

.NGK BKR7E PLUGS gappped at 0.30"

.magnacore 8.5mm HT leads

 

 

hi all right another problem! after the car was missfiring when i installed the xs-power T-61 turbo kit (at low rpm and nearly all the time from idle) i fixed this by replacing the stock lambda sensors and it worked perfect! but it hadnt been mapped yet! (so i hadnt drove it past 3000rpm) but the car was great! now ive just had it based mapped and the mapper said its nearly a full map he has installed! but we couldnt do a full map as it was missfiring under boost this time!

so the mapper said its nothing to worry about just install new leads and rotor arm and new distributor cap and it should be fine! so i fitted new magnacore 8.5mm leads, brand new 4 runner cap, new rotor arm, and a set of NGK BKR7E PLUGS and i gapped them at 0.30" and its still missfireing, its like hitting the rev limmeter at 4000rpm at 4psi. ive checked the leads and they are the rite way round and so is the 4 runner.

 

i can get all the way up to the limmiter just as long as i dont boot it so its looking like when it starts to hit 3-4psi.

 

here is a video we took of the boost gauge (on the right) and wideband (on the left)

 

i would so appreciate your help! and any one that has the answer that fixes this problem i will send £20 to your paypal :wink5:

 

image

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here is a video we took of the boost gauge (on the right) and wideband (on the left)

 

The boost gauge is on the left and the wideband is on the right ;)

 

Looks like it's going into the 10:1's just before the misfire, it might be misfiring because you're overfueling when on boost. What duty in milliseconds are the injectors running at when you go on boost? The E-Manage can datalog that stuff so you should be able to find out.

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The boost gauge is on the left and the wideband is on the right ;)

 

Looks like it's going into the 10:1's just before the misfire, it might be misfiring because you're overfueling when on boost. What duty in milliseconds are the injectors running at when you go on boost? The E-Manage can datalog that stuff so you should be able to find out.

 

i wouldnt know mate as rayn from 2bar tuning set all this stuff up? how would i even find that? cheers mate

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You see, where you went wrong, was buying an ebay turbo kit:d

 

Anyway, joking aside, it could be an over fuelling problem, but I would assume Ryan would of picked something like that up.

 

I'm sure more suggestions are on the way, but could it actually be the opposite and the stock injectors can't keep up?

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You see, where you went wrong, was buying an ebay turbo kit:d

 

Anyway, joking aside, it could be an over fuelling problem, but I would assume Ryan would of picked something like that up.

 

I'm sure more suggestions are on the way, but could it actually be the opposite and the stock injectors can't keep up?

 

i got the kit from xs-power them selfs lol but i know its cheep! lol

em i dont think its the injectors as quite a few lads on club na-t are running the same set up with no problems at all. im just stumped

 

thanks for your input mate ;-)

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i would look at the plugs, leads and dizzy. Have you advanced the timing, i presume so....

 

the plugs are brand new (from monday just gone) leads are brand new and uprated, dizzy is brand new , rotor is brand new!

 

ive just changed all of thease! as ryan told me to after he was trying to map it! but couldnt do a full map because of this problem! and now i have changed all of this the problem is still there?

 

i havnt touched the timming mate?

 

thanks for your input mate ;-)

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Take the efi fuses out and put them back in after 30 seconds, and check if there is water around the spark plugs.

 

there was no water around the plugs when i done them monday and the problem was there before that! and i also disconnected the battery as im sure this will work the same as taking the fuses out!

 

thanks for your input mate ;-)

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Hi Jamie

 

Leave the dizzy timing alone bud that wont be causing an issue like this, neither will the air/fuel ratio dropping into the high 10's.

 

Couple of things i want you to check mate

 

- Coil and Ignitor are grounded properly on the chassis

- Check for cracks around coil

- Get Jumper settings of the EMU and post on here

- Bypass the Ignition side of the emu as a test in case its an issue with emu

 

Get cracking!

 

Ryan

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Alright jamie.

Dont worry we'll get to the bottom of it mate. ill have a good luck tomorrow, but I suspect its an electrical issue maybe due to the heat generated from the turbo.

 

oh hey mate just relized who it is pmsl. cool cool mate im pulling my hair out here lol

 

ryans just called me he wants me to check a few things like jumper settings, coil etc...

but ill bring it to jne tomorrow for you to give it a scan lol ;)

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