hi i'm starting to go insane with my car now
the thing is it hesitate/holds back slightly from 4000rpm onwards
list of things ive changed since the problem started
fuel pump walbro 255
fuel pressure reg fse set at just over 2bar idle raising to just over 3bar on load
spark plugs 7b's
coil packs all 4
mass air flow

all these parts are new yet the problem still persists any help would be great as i'm fresh out of ideas now

 

clean the boost solenoid may help.

 

tweaks just curious did you ever sort this problem?

 

woah yes, this is a while back.anyway after it driving me crazy i started putting it back to how it was when i bought it.found spark plugs had cracked down the insulator round the electrode,set them back under warrenty got some more also put standard f.p.r on and it ran a lot better.plugs were the problem tho,it just didn'tfeel right with the f.s.e f.p.r. this was ages ago now tho currently using a fuel lab reg which is great,i dont rate the f.s.e reg

 

cool glad you sorted it, ive currently got similar sort of problem as you had but narrowing it down is a nightmare theres a million & one things it could be, what did you gap the 7bs to? i've tried 0.65 & 0.7, things ive renewed are plugs,coilpacks,walbro,lambda, cleaned all boost hoses & maf also done the maf test & all is ok it just seems to hesitate under high boost, i dont think many people rate the fse regulators they dont seem to hold the pressure as they should

 

have you done the ecu fault code check then ???

 

yes not bringing anything up, i have got a full decat fitted so it does slightly overboost but doesnt hit fuel cut at all & it was the same before the downpipe was added, this is happening mid boost

 

if its not bringing fault codes up its something mechanical.vacuum pipes etc anything that ecu doesn't pick up on.i had the same thing shortly after i sorted the first one (the day after!!!!) turned out that after i'd fitted the o.e reg i'd forgot to nip up the jubilee on the intake pipe on the back of the maf(what a numpty,stress levels were still high is my excuse)therefore it was drawing in unmetered air and caused the problem your having

 

im going to try & replace all the vacuum hoses eventually but from eye they all look ok & nipped up tight, could just be a pin hole somewhere you never know, im going to get it rolling roaded in a couple of weeks see what they reakon, the thing is with the early classics theres not alot diagnostics wise they can do, a mate had his rolling roaded & a diagnostics on his 93 wrx other week & they only checked for det & looked at the fueling on the graphs

 

thats prob all they'll do with yours,thats why i never bothered.
trouble with problems like these is you need to start at A and work through to Z sometimes.

 

like you said drives you insane but sure ill suss it after ive spent more on it that what the cars worth thanks for your help anyway, dont suppose you've got a picture of your fuel reg plummed in i was thinking of getting one soon is yours running on the standard fuel rails?

 

yes std rails i'll take one for you but unsure how to host it so i'll put it in my garage tomorrow

 

nice one if you dont mind, i use a site called photobucket you upload it onto there & then theres a tab says img code click on that & it pastes it then copy into here & it shows the picture

 

nice one i'll try that first then

 

Have these cars been remapped?

 

mine has now was running standard ecu when i had problems.sorted before mapping
w13dle sorted the photobucket thingy

 

cool, yes im running a polar performance chip but also got a z4 ecu & same on both

 

I asked as i cant see the point in running aftermarket FPR,s and 7b,s on unmapped cars. Better off with 6b,s

 

fitted walbro so did it out of caution(f.p.r)as a lot are overcome by uprated pump(known two do it now)and fitted 7b's because of the mods i had lined up

 

i followed andy forest's Level 1 290-300bhp & he fits 7bs & a fpr & also as tweeks says its best to fit a fpr as the uprated fuel pump can overcome the standard fpr