bigbl

hi there,i am experiencing a loss and pickup of power between 4-6k rpm, its not overboost as its a smooth hesitation as if someone is dabbing the brake pedal.boost holds fine at 12psi(was 15psi but i have fitted a cat and silencer so its dropped)i have fitted new coil packs as it was spluttering before i changed them(they were cracked at ends) and i fitted ngk plugs gaped at 0.64mm by me. i have checked all vacume hoses and boost hoses and i changed the boost solenoid(it has restrictor pill in) i was experiencing lean readings on my maf and have an idea the lambda is knackered due to input from a previous thread.could this cause these symptoms or maybe a faulty maf?engine specs below thanks bryan


95 wrx with front mount,full stainless steel exhaust with 3" downpipe,k&n induction,adjustable fpr,stainless steel headers,walbro 255 pump

DJ_Jon

iTrader: (7)

Sounds an awful lot like a duff MAF sensor, I would check that first before anything else & don't drive it hard till you get this issue sorted, IMHO.

bigbl

thanks for the reply dj_jon would a faulty maf give these symptoms? thanks bryan

w13dle

iTrader: (5)

Hi mate I'm suffering from similar problems as you but still not got to the bottom of it only thing I haven't replaced is the maf, have you tried cleaning it with carb cleaner? Also have you done a ecu check? I don't think the lambda becomes a problem on boost I might be wrong

bigbl

hi mate,i have tried cleaning the maf yes,i have a new lambda on the way too,there are a few second hand mafs for sale but im not sure about buying second hand,might be as well sourcing brand new although well over priced,i want to know if its the maf at fault first so need to test it

r1c

iTrader: (9)

you can get a hesitation from a lambda but most likely is the MAF, just out of interest pull the MAF sensor plug off and look at the connectors in both plug and sensor, mine keep going green and getting this problem since i cleaned and moved the drain for the vent covers its been fine. Not saying this is it but iv can say iv seen it before.

w13dle

iTrader: (5)

Yes there very overpriced but the green mafs are but supposedly more robust that others, where's abouts are you located somebody might be able to help you out with one to test, I've purchased a second hand one off here to eliminate it but still waiting for it been 3 weeks now

bigbl

will try the connectors,cheers.going to try a mates in place of mine tonight so will see if that does it

w13dle

iTrader: (5)

let us know how you go on mate would be interested to know as having similar problems, another one could be a faulty coil pack im not sure on how you test these though, have you had it rolling roaded to see if fueling & everything is ok?

fastmike

iTrader: (4)

I have a MAF sensor for a classic if anyone needs one, PM me

TonyBurns

iTrader: (3)

Not all the MAF's are the same for the classics so you will have to state what year car its for

Tony

fastmike

iTrader: (4)

Its off a 96 phase 1 and it has a green label AND I,m prepared to courier it so whoever needs it gets it Tuesday

bigbl

i am checking the maf against my mates tomorrow as i couldnt get round to it tonight,i havnt had it on the rollers since new engine went in so not sure about fueling etc,ironicly im going to wait till its running properly and see what it does on the rr. tonyburns are you saying all green label mafs are not the same? i thought i could use any green label maf for my 95 wrx? anyway fastmike how much are you after for the maf? is it brand new? cheers bryan.

fastmike

iTrader: (4)

bryan it isnt new no , and I would like £45 for it please

bigbl

i tried a maf change with my mate today and no difference,i reset the ecu first before running with the different maf so that rules the maf out,my lambda sensor arrived today so will try that tomorrow.i am thinking maybe its a faulty plug now as i only gapped the old ngk plugs to 0.65mm(didnt fit new ones),think i will try a new set of plugs too.i will update this when i try these changes thanks bryan

bigbl

changed lambda this morning,i now get correct voltage readings and my afr gauge works perfectly,so i know the old one was shot, still missing above 5k though so the last thing i can try is plugs.

w13dle

iTrader: (5)

yes id give the plugs a try next mate as there only cheap & worthwhile sticking new in anyway, your symtoms seem exactly same as mine ive also put new coilpacks in,lambda,2 different sets of spark plugs gapped to 0.65,actuator, cleaned all hoses solenoid & its throwing no codes up either, running out of ideas aswell, i mentioned about the rolling road as it can highlight any problems mine showed a strange sudden drop off of power at 6400rpm which im told could be a faulty coil pack even though there new so if you try the plugs & its not them maybe a possiblilty

bigbl

im going for a set of plugs now,as regards to the coil packs i bought them brand new so unlikely to be them but it was just the 4 for 195 quid of ebay ones,dont know if that was the ones you bought w13dle? i have a mate thats going to give me a set of coil packs to try just incase. will let you know if the plugs sort the problem. thanks again bryan

w13dle

iTrader: (5)

thats a good price i got mine from camskill there made by diamond about 65 quid each, like you say probably unlikely you have a faulty one but you never know its something else to eliminate

bigbl

fitted new plugs,all i could get were ngk pfr6bs, i know these are for standard power turbo engines but with my boost only at 13psi these should do just now,anyway.....no different!!! this is starting to get on my **** now. when i rev it from under the bonnet lightly i can hear the boost solenoid(or something there) clicking very fast,is this normal? any ideas on this is welcome and i will give it a try. thanks bryan

w13dle

iTrader: (5)

The 6bs will be fine mate I've known people to still run these at 340bhp but obviously the 7bs will run cooler, the boost solenoid should click when reved that's normal, noticed another thread you was asking about the uppipe this could be a posibilty if leaking, I thought I'd got to the bottom of it with mine I notice a hole but turned out to just be the skin, have you got any further with it? Cheers mark

bigbl

cheers mark,i have ordered a bleed valve and im going to set the boost manually on that and bypass the boost solenoid.i will start with the 0.5 bar boost and see if it runs smooth and dial up bit by bit, i really need to get it on a ramp and investigate the exhaust gaskets. i will post the results when i do it,thanks bryan

w13dle

iTrader: (5)

from reading this old post the stainless headers could be a problem aswell for the low pick up your seeing https://www.scoobynet.com/general-te...ce-needed.html, think thats my next task aswell checking all gaskets it looks like my headers have been messed about with in the past looking at the bolts

bigbl

very interesting reading there on that thread,i will definitely be changing back to standard headers,can renew gaskets when changing too,need to wait till weekend though,my mate has the standard headers from the original set up so that's next on my list

Slystav

iTrader: (1)

Hi guys,

Maybe coincidence but this sounds a bit like my problem over on this other thread - could you please take a look?

Thanks!

https://www.scoobynet.com/drivetrain...juddering.html

bigbl

hi mate,i think my problem is boost related and i think yours is non turbo,have you got to the bottom of it? i will post whatever i do to fix this problem for future reference(if i ever get it fixed lol)

dbay

iTrader: (21)

ive got the same problem to. my thred is 0.5 bar is no fun. maybe its the v power hope you get it sorted so i can fix mine

w13dle

iTrader: (5)

the replacement maf turned up yesterday but still no different think im on par with you now mate i give up

bigbl

fitted a bleed valve today,started off at 7psi and drove fine,just slow as *** and wound up bit by bit till i got to over 10psi then it misses on boost,so if i keep to 10psi I'm fine just slow,my gauge doesn't read in bar by the way its psi so should reach 15 before over boost kicks in.going to try changing headers over weekend and check gaskets when refitting standard ones back.I WILL BEAT THIS EVENTUALLY HAHA!!!

dbay

iTrader: (21)

i dont know the exact cut target but it will be about 14psi ish, try a differnt gauge, mine felt slow until i put a different gauge on

hope you fix it soon