Help please. I'm giving it one last go!

[Shinsplintz 101]

Take my advice - if you want to modify a T5 then by all means do - but budget for a bespoke Map from either Tim Williams or Shem.

Increasing the MAF housing / larger injectors or strapping a ruddy great blower on will all end badly with an off the shelf map.

These cars can be picked up cheaply - and are simple to modify up to about 260-280 bhp. But modifying them up over 300 is an art form - do it wrong & you might as well sit in the garden burning tenners - it'll be cheaper & less frustrating.

Go back to standard & hopefully you haven't knackered the engine - would be a shame to see another potentially good T5 get broken through misguided mods if the engine is slag. You're not the first & you are unlikely to be the last.

Good luck.

[Mkengineering]

Originally Posted by Shinsplintz 101

Take my advice - if you want to modify a T5 then by all means do - but budget for a bespoke Map from either Tim Williams or Shem.

Increasing the MAF housing / larger injectors or strapping a ruddy great blower on will all end badly with an off the shelf map.

These cars can be picked up cheaply - and are simple to modify up to about 260-280 bhp. But modifying them up over 300 is an art form - do it wrong & you might as well sit in the garden burning tenners - it'll be cheaper & less frustrating.

Go back to standard & hopefully you haven't knackered the engine - would be a shame to see another potentially good T5 get broken through misguided mods if the engine is slag. You're not the first & you are unlikely to be the last.

Good luck.

The only things is I told shem what things I've done. And he supplied me with the map.

But I'll revert back to standard ie.

Reinstall the standard injectors
Install the standard maf housing

[taiwan740]

Originally Posted by Shinsplintz 101

you might as well sit in the garden burning tenners.

fun fact, they do this in Taiwan. You buy "ghost money" and they put it in a little ceremonial burner. Quite a big economy

https://en.wikipedia.org/wiki/Joss_paper

[Laird Scooby]

The one thing you haven't checked/changed as far as i can see is the one thing that determines mixture - the Lambda sensor!

They can go out of spec and cause major over-fueling WITHOUT throwing a fault on the engine management system or bringing the EML on.

I've seen a Lambda sensor fail during an emissions test for the MoT and when the CO got up to 9% (from 0.00% when the tst started) the tester pulled the hose out of the tailpipes.

It took another hour before the EML came up on the dash but i'm fairly sure it had been dodgy for a while because occasionally it would give a puff of black smoke out the back end when i hoofed it.

I'd investigate the Lambda sensor before pulling various bits off what was seemingly a working combination.

[Derek UK]

White smoke maybe head gasket or even brake servo leaks. Have you done a compression test?
Does it pass the rubber glove test that checks that the PCV is working OK?

[Laird Scooby]

Originally Posted by Derek UK

White smoke maybe head gasket or even brake servo leaks.

White smoke could also be turbo seals leaking due to worn bearings/seals. It could also explain the strange idle as the oil from the turbo would supply extra fuel and the leaks, extra air. I've known that happen on a few diesel engines and also disels that have been converted to spark ignition running methane.

If the turbo is leaking air in, the Lambda sensor (assuming it's working) will add fuel to the mix causing high (but not high like that is) consumption.

Of course it could be a leaky injector letting fuel out all the time as well..............

[taiwan740]

Originally Posted by Laird Scooby

White smoke could also be turbo seals leaking due to worn bearings/seals. It could also explain the strange idle as the oil from the turbo would supply extra fuel and the leaks, extra air. I've known that happen on a few diesel engines and also disels that have been converted to spark ignition running methane.

If the turbo is leaking air in, the Lambda sensor (assuming it's working) will add fuel to the mix causing high (but not high like that is) consumption.

Of course it could be a leaky injector letting fuel out all the time as well..............

If turbo was providing oil, as it's a petrol engine it would chew on it, i.e. revs would reduce and you'd get blue smoke. Diesels the other way around, the example you describe here is how most modern engines result in "diesel runaway" - this doesn't happen with petrol as it would just flood itself and stall.

Most likely in this case, I'd say its overfuelling. Especially given the ****e consumption that OP has already stated.

[Mkengineering]

So is everyone saying I change the o2 sensors?

As there are 2 sensors on this car. Someone told me that the sensor at the front is basically a moron while the rear sensor does all of the mixture.

[Simmy]

Originally Posted by Mkengineering

So is everyone saying I change the o2 sensors?

As there are 2 sensors on this car. Someone told me that the sensor at the front is basically a moron while the rear sensor does all of the mixture.

rule one performance and economy never come together.

[Laird Scooby]

Originally Posted by taiwan740

If turbo was providing oil, as it's a petrol engine it would chew on it, i.e. revs would reduce and you'd get blue smoke.

Petrol and oil mixed and burned = blue smoke

Oiil burned by itself (eg as a result of oil leaking past turbo seals) = white smoke.

Over fueling (petrol or diesel) = black smoke.

First one indicates engine wear so crankcase oil is moxing with the combustion charge (diesel or petrol) whether due to worn bores/pistons/rings/valve guides etc or pulling in through faulty PCV system

Second is best demonstrated when a turbo fails and oil from the engine lube system enters the hot turbine housing and self-ignites

Third is typified by the USA trend for "rollin' coal" - turning up the diesel feed to overfuel and belching black clouds of smoke out of the exhausts.

However on some engines the cold start is cahieved simply by overfueling, worked on a few of those in my time as well, a 1963 Coles crane by Southampton Water was particularly memorable,

It wouldn't start due to a charging problem and the battery kept going flat for the same reason (parasitic drain from a faulty regulator - pre-solid state regulator at that age of course!) but varying people had been trying to get it to start, all to no avail.

I put right the mistakes they had made, sorted the regulator, charged the batteries and fired it up.

Definitely a "Deep Purple" moment!

Another memorable one was a pair of 6-pot Volvo Pentas in a split-hull dredger, the hydraulics had failed while opening the hull to discharge the cargo and the two halves had gone further than designed to and severed the multicore cables (40 if memory serves in each plus a master with about 120 in feeding them and some other stuff) feeding each hull and engine and bringing signals back to the GACs in the engine control room.

After rewiring the whole shooting match, i had to fire up both engines and test all functions including the charging alternators on each engine and the generators. No glow plugs on those either so again, it was overfueling for cold start.

At least this time it really was on the water, not just next to it and instead of the slow, rhytmic growl of the Gardner 6-pot in the crane, there were two straight-6 howls from the pair of Volvo 6-pot diesel Penta lumps, each belching a plume of black smoke out.

Going back to my point, even in a petrol, if the turbo fails it can suck oil in from the worn bushes/seals and fire it into the inlet manifold, already compressed so when it reaches the combustion chamber with the petrol, it will burn separately, producing white smoke when the fuel ignites, hence a mix of black and white smoke if it's overfueling.