got a prob with my s2 rst when it comes on boost it stop's suddenly like i just hit a brick wall,backfires then pick's up again? could it be a fueling prob? its bn chiped/standard intercooler peaks bout 16psi and holds bout 10. if thats any help, cheers

 

Hi mate has it only done this recently or for a while?

Could be something on the ignition side breaking down,

As its getting really cold now it may of overboosted but that maybe
unlikley, feels like its backfiring but useally a little more violent

 

i had the same probem with mine last week and turned out to be the altenator was shagged

 

If its definately chipped it could well be the sensor in the dizzy breaking down.

 

Even if it has been chipped, its possible that the boost-cut hasn't been removed altogether. Some raise it to 18psi and it could be hitting that due to a boost spike, probably the result of a weak/poorly adjusted actuator.

That's where my money would be.

 

where were you when a thread kicked off the other weak when people started saying ALL chips remove the boost limit!

 

LOL. I think you will find that Ahmed does an 18psi cut and a 24psi cut. Not really sure why though.

 

Ah right like that is it

 

its only started doing this since i fitted the new actuator, i ajusted the timeing by moveing the dizzy yesterday it seams better now it only seams to do it in 3rd gear when i get to bout 80mph.

 

Boost limit if you ask me.......

 

I'll second that you've probably set the boost too high if you've put a new actuator on

 

U lads mite know.....my s1 is pinking when it comes on boost on hard throttle, any ideas???

 

Yes, too much ignition advance and/or too much boost.

Keep at it, and u'll have no engine left...

 

it boosts 0.5 bar which is standard, could it be dizzy, or ecu?

 

it COULD be a lot of things...

Has it just started doing it?

 

it broke a piston ring a while ago, and pulled it 2 bits and fitted new rings, and i reckon since then it hasnt been right

 

more compression then. Twist the dizzy to retard the timing a touch, and see how it goes. Should cure it.

 

clockwise if looking from the gearbox end?? Also its got bad back pressure tho......

 

no, anti clock wise if looking at it from the box. Dont turn it more than a couple of mm.

How do you mean, back pressure issues?

 

yeah it blows the cap off when giving it a bit boost, there was a bit of a lip on the block wen i had it in bits

 

Blow by. You've left the block as is?

 

Re-build time

 

Just gave it a hone out...... rekon it needs re-bore and oversize pistons??

 

You shouldn't really re-bore and use standard pistons, especially the amount you would of honed to remove the wear etc.

You've got to remeber the next size pistons up are 0.5mm oversize.......that soon gets used up in honing

 

Well its off the road at the end of the month, so the engine will be out and down 2 the local engineers to get measured up n see wot i need, there was a guy on here selling re-bored s2 block and new 0.5 pistons for £400, but realy want to keep original block..... as its totaly standard and only done 72k

 

so what if it's std - its worn to hell!

 

Mileage doesnt necessarily reflect anything as you are proving.....its only done 72k...........a very hard 72k by the sounds of it!

A well looked after and maintained engine should be seeing a lot more than that