running issue (slight mis/pop from exhaust)

hi, when i picked up my car, on boost it was jerking/popping/holding back.

i fitted another coil from bob, and hey presto, immediately it fixed this.

over the past few weeks i have noticed im getting a slight running issue, i mentioned it to bob and he said to check maf connections incase its a loose connection, but i have now realized after doing many miles in it, there is a distinct pattern to when it will do it.

when cold, intermittently around 2-2.5k revs for a split second it will hold back/misfire, only for a split second, then its fine.

to add to this, i have given it a bit of boost when cold (not good, i do let it warm up this was more of a accident lol) but i found out that it held back/missed/poped from exhaust while on boost, no real pattern to this.

the above 2 problems seem to be completely gone once its warm (the 2nd isnt an issue to me because i only use boost when its warm but im sure it might be highlighting a problem somewhere?)

the next issue is the one with the same driving pattern and it happens when warm.

il start by saying, if i start off in 1st gear, and rev it hard in every gear, and drive like im on a race course i have no issues.

if im just cruising about normally and suddenly drop down a gear (to 2nd or 3rd) or boost it in either 2nd or 3rd, at either around 5,000 revs OR once i have up shifted to 3rd or 4th gear and put the accelerator back down again, it will just suddenly completely hold back (engine sort of goes BURRR and bogs down) and i get a loudish pop from the exhaust, once its done this, it doesnt seem to do it again, and it wont 'always' do it, but it always does it in the same way/same way of me driving, and it is more likely to do this if i drive the car, let it cool down again for 10 minutes, then go out in it again (in the period before its warmed up again from the heat lost in those 10 minutes cooling down)

i know this is a bit long to read/understand, it doesnt really cause me any issues but id love to sort it

hi mate, check your leads might be on ther way out 0r timing

You able to check for any fault codes mate?

Does it still boost the same or does it hold back?

Dizzy cap and rotor arm would be my first place to check... Mine did this... Exactly the same symptoms

buckym120 wrote:You able to check for any fault codes mate?

Does it still boost the same or does it hold back?

im not sure how to.

when it happens it just bogs down completely, stops revving, obviously immediate instinct is release the throttle, so no idea what would happen if i kept it down.

GTI_R_IOW wrote:Dizzy cap and rotor arm would be my first place to check... Mine did this... Exactly the same symptoms

it has a new cap/rota arm, but leads would be a good idea i suppose, the are aftermarket sporty ones, but i dont think bob rates them very highly.

try another set of stock leads, im assuming the plugs are new
could really be a number of things but as said try doing a faultcode check on her first as it may be bringing something up.
could still be an afm prob too, never rule that out unless you change it