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Safe to drive a car for remap?


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I have just fitted the turbo to my car, and need to get it the 3 miles up the road to the place that's tuning it for me. My O2 sensor however is all over the place, and reading about 9, which is a tad rich!!

Is it safe to drive for such a shirt period of time. That's if it'll drive as cuts out even trying to move it on the drive.

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Its better being rich than lean tho

A common myth....

Too lean will melt your engine, too rich will wash bores/rings and contaminate oil causing bearing failure - which is better?

9 AFR will cause black smoke from the exhaust and wash the piston rings way.

I wouldn't drive it anywhere like that, sounds like you have injectors twice the standard size.

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The injectors are saab turbo's at 4 bar.. i'm running 4 inch maf housing too and 8.5:1 compression.

and yes there was black smoke to start but did clear, i suppose the car has adjusted fueling as much as it can.

when i say 9, i mean that's what i've seen it at, left at idle it'll rise to around 13 to 14 pretty quick, then can jump around a bit as soon as i touch accelerator.. just not sure why it cuts out unless i hold the revs up for a few seconds before lifting off the clutch.

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not sure why it cuts out unless i hold the revs up for a few seconds before lifting off the clutch.

A few reasons but mainly because it is far too rich

Thanks for clearing that up. i had a feeling it was this because the natural thing to do if it tries to cut out is try and build revs up, however this makes it worse. leave it to its own devices and it'll be ok and ratio will rise again.

i think i will have to look into it more before driving it there. it actually was a hell of a lot better after running for a few minutes. how long does it take for the car to adjust its fueling? or as much as it knows how to, to try and keep readings within tolerances?

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Its better being rich than lean tho

A common myth....

Too lean will melt your engine' date=' too rich will wash bores/rings and contaminate oil causing bearing failure - which is better?

9 AFR will cause black smoke from the exhaust and wash the piston rings way.

I wouldn't drive it anywhere like that, sounds like you have injectors twice the standard size.

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Very interesting! I wouldnt be surprised if that is what happened to my 1st vr all those years ago! Been told running it rich was ok for 150 miles to get it mapped!! No wonder i got the issues i did! The black rear window was the least of my probs lol!

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I thought about running old injectors a while ago. i suppose easy ish for me as i have a short runner manifold.

however, will the combination of standard injectors and 4 inch maf make it run lean? the maf being an inch bigger would surely only read half the actual air flow? or could i help this by running it without the maf plugged in and rely on other sensors?

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Ok, have had a play around today. Standard injectors are back in, air flow meter plugged in it's running lean, with it unplugged it runs the same as if did before when my MAF packed up. Kind of flickering between rich and lean, between say 13 and 16.

No more smoke, and I actually managed a drive round the block to make sure it can do the 3 mile drive up the road too!

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