What to check?

Took the supra for a quick drive today just to stretch its legs.

After just pulling out the street I noticed the A/F was really rich 10.00-10.01, so I thought just let it warm up.

After about 20mins it just jumps stright over to normal so by this time it had been running warm for quite a while.

Then I pulled up and let it idle for about 5 mins and I just heard the engine note change and I glanced at the A/F gauge and it jumped back down to 10.00 then after about 30seconds the engine note changed again back to a deeper note and the A/F jumped back round to 14.7-15.00 (normal).

Then I decided to take it home as there was obviously a problem with it so on the way home it looked to be normal I put my foot down just enoght to hit a little boost but not flat and it felt like a slight flutter/ missfire.

Now last time I had a missfire it was really bad and I replaced it with a second hand coil from Keron and this fixed it.

However this time it only feels ever so slight!

Now I just wanted to ask what you guys recommend checking so I can add to the list when I get the chance to poke around?

I've had a quick look a the vacume lines to make sure non popped off and they havnt.

So I'm going to check for splits in the vacume lines

And ill check the coil out, if I can't find any splits I thinking of replacing the coil with a brand new one but I can't see the coil causing it to run rich?

Cheers guys

If you end up changing the coil again try one of the bobs bargain ones from import car parts I posted on the other thread then you know its nice and new

If you end up changing the coil again try one of the bobs bargain ones from import car parts I posted on the other thread then you know its nice and new

Yeah I will do bud, I think I'm going to just do it anyways mate but I'm not sure if that's causing the problem lol

Plumb your boost gauge into the same hose as the MAP sensor and check the gauge reading when it happens again. If it goes from vacuum to atmospheric pressure, it would indicate a split hose feeding the MAP sensor.

Otherwise you need to see what your narrowband O2 sensor is reading when it goes wrong, could be it goes to 0v so the ECU goes mega rich thinking it's all gone lean.

Plumb your boost gauge into the same hose as the MAP sensor and check the gauge reading when it happens again. If it goes from vacuum to atmospheric pressure, it would indicate a split hose feeding the MAP sensor.

 

Otherwise you need to see what your narrowband O2 sensor is reading when it goes wrong, could be it goes to 0v so the ECU goes mega rich thinking it's all gone lean.

Nice one mate, I think I've got another 02 sensor there so ill just change it over anyways

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Anything else I could check/ look at?

Cheers

You said you changed the ignitor, i assume the leads are in good nic too?

Nice one mate, I think I've got another 02 sensor there so ill just change it over anyways

 

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Anything else I could check/ look at?

Cheers

Could be the wiring though. Unless there is an obvious physical problem with things, leave them in place and check before doing random part swapping

You said you changed the ignitor, i assume the leads are in good nic too?

Yeah brand new 8.5mm leads mate

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Could be the wiring though. Unless there is an obvious physical problem with things, leave them in place and check before doing random part swapping

Will do mate and big thanks

I'd say more likely lambda sensor playing up, or map sensor

Are you running a piggy back? If your still running the stock ecu the lambda sensor wires you can check at the diagnostic port as it has two pins that splice into it from the O2 sensor wires