Been for a run in the car and once into 3rd gear revs about 4-5krpm there is a pop, momentary loss of power for like a second and then fine again.

Does not happen in first or second gear.

The pop and loss of power is like when your boost hose collapses or the spark is blown out.

Its running NGK BCR8ES plugs gapped I think at 1mm. I have new 071's to fit.

It has been sat out in the heavy rain for a few days and has a K&N cone filter and metal shield fitted under the bonnet vent.

Have changed the dizzy just recently for one that did not have a broken sensor mount but this was fitted to the same mark as the previous dizzy. Cap and rotor arm are both in very good condtion.

Just worried in case I break something (again ).

 

coil or afm nakerd or damp seen the same actions after a engine steam clean
leave to dry or even try too air line the plug leads and plugs that attach the electrics worth a try

 

Thanks mate I hope its something simple cos it wasn't doing it a few days ago. Jus hope its not running lean at all.

 

The coil was a new grp A item. Have checked the plugs and the gap was less than I thought. Anyway tried my 071C's ad no difference its still backfiring on boost.

Ignition timing maybe? HT Leads? Have ordered a new set of Motorsport leads from Matt Lewis so can't get here soon enough.

 

Well its not the dizzy either as I just swapped it back for the old one.

 

is your wastegate in good working order?? when mine did this, changed with a -31. Now after six months running higher boost (after setup), working a threat

 

Is it chipped? if mot it may be hitting boost cut at around 11 psi, also spark plug gap is supposed to be nearer half that at .6mm iirc

 

It is chipped as I was running 15psi before the new engine went in. Just tried new HT leads and still no joy. Supposed to be going to a track day tomorrow but that won't be happening now .

 

PROBLEM SOLVED!!

Was checking the hoses and the one that runs from my boost valve to the turbo had split at the end. Must have been caught when I re-fitted the turbo from underneath .

If it needs to ever come out again its coming out through the front instead!

 

well done