Really need help I'm lost now

[damowrx]

Hi there, I have MY99 RB5 Wr sport I bought it to restore to its hay day. It's never ran well wont go past 3000rpm boosts at 7psi it's like your being held back and it back fires etc, I've replaced MAF, MAP sensors I've changed spark plugs and replaced Sti ecu back to rb5 ecu bought full brand new decat exhaust. I've also changed the boost solinoid.

It drove better today after fitting right ecu but still is being held back and misses fires when u sink your foot down if you press slowly it works fine until 4000rpm then stutters and mis fires etc

Can somebody help me as I've now ran out of cash and really need a car any advice is welcome please help.

Many thanks Damian

[spect]

Did you change all of those bits as guess work or did you plug in a scanner to get any fault codes? A diagnostic test may help if you have not done one yet. At least you will know if there is anything logged in the ecu. The fact that you changed that and the other bits but it has not fixed it suggests maybe a wiring problem somewhere between the various sensors and the ecu. Maybe a mechanical setup problem too. There is so much to check. Have you done a service recently? Cambelt change? What is the fuel consumption like?

[damowrx]

Hi mate I changed sensors due to fault code readings I got when I bought car so I tried to eliminate them one by one. I gave it a full service when I got it. £20 is getting me 89 miles at mo but it's never revd over 3000rpm as it just back fires.

It also had fuel leak at fuel rail when I investigated it I found they have cut off metal pipe at end of injector rail and replaced it 8mm fuel line piping under inlet manifold to reach other injector rail on opposite site. Would this affect it?

Do you think it's worth getting timing checked out?? As I'm totally lost now I've done all I can

[ciaranrb5]

First check the fault codes and check they are clear. If not replace what needs done. Does it sound normal?

Are the intercooler pipes on ok? I experienced a similar thing when i had a split pipe.

[damowrx]

No fault codes showing for weeks now I just got ecu today as it had Sti one on it.

The intercooler fins look badly damaged I tried to straighten them out to allow air flow. It drives fine until 3/4000 rpm then prob starts boost hits 7psi and car just hits flat spot and splutters.

[ciaranrb5]

Take it to specialist im sure they will sort it at a decent price

[damowrx]

That's the prob I can't I lost my job due to an injury and spent my last £100 getting new and right ecu for it. Thanks for all your thou I'll just need to sell old ecu and see if I can get enough to take it somewhere. Cheers guys

[spect]

the flat spot sounds like an air leak. The fins on the intercooler will make no difference to your problem. The fault code will tell you there is a problem in a system but not always the component that is faulty. If you have the same codes with the new ecu then you can eliminate the ecu. I am afraid that trying to do this on your own is going to be damn near impossible unless you know your diagnostics. I would say you need a specialist as well. Maybe someone from here can help you out. to me it sounds like more than one fault, maybe fuelling, plus air leak plus maybe an electrical problem. Good luck.

[colin_ross]

I'd start with the basics.

You've changed the plugs already, pull them out and have a look at them. Are they the normal coffee colour or sooted up or oily? If they are you may be over-fuelling which would point to a boost leak. If not check they're gapped correctly, 0.7mm if memory serves. Weak spark could be another cause. Being an rb5 you should have the single coil pack, easily swapped out. Borrow one to check and save you spending more cash.

Another thing to consider is that the sti and the rb5 ecu's are not a direct replacement for ecu other. They'll have the same plugs but I'm certain that a couple of the sensors need to have their wires swapped over. A couple of minutes on google should confirm this.

Also, list your mods. Not everything on the market performs as it should and someone may have had a similar issue.

Keep at it mate. If you don't mind doing the basic stuff yourself I'm sure you'll get to the bottom of it.

[damowrx]

Thanks guys

Only mods are full stainless steel decat exhaust

Blitz air filter that's it.

When I bought it it had Sti ecu in it with 3 fault codes I was told it was wrong ecu and change it so I have but car still same tonight on a test drive no fault codes showing.

The plugs look nice colour and not dark or black. When I got it the boost pipes were all hanging out and a bleed valve was there I ripped it out and got diagrams to fit boost pipes back in right place for a 2 port solenoid maybe I've done this wrong or something.

Thanks again guys.

[colin_ross]

Any smoke, rattles?

Do you have the vent covers on?

[damowrx]

Any smoke, rattles?

Do you have the vent covers on?

no smoke but lots of water carbon deposits out exhaust, no the guy took vents off, i have a wrx and when airfilter gets wet this is how my rb5 is acting spluttering, lack of boost, backfire thru air box and exhaust sometimes, ive googled rb5 ecu probs and most posts i found say its boost solenoid needs cleaned and check MAF area as these common faults on these models?

ill drive it upto temp and ill disconnect maf sensor to see if theres any change in engine revs, i meant to say it hunts when on idle and ticks over very low and revs up and down alot.

i cant find right photos to make sure ive connected boost pipes right i do know the restrictor brass ball is missing but boost say its on 7psi.

i dont want to drive it now as im scared i'll damage engine?

im trying to sell bits off my wrx to pay to make rb5 the way it was but i just cant get it sorted,

thanks for all info

[spect]

Sometimes boost gauges cause problems too!

[damowrx]

It was like this before boost gauge the fit I got it off was an idiot honest

[damowrx]

Right checked Maf once car got up to temp when I pulled plug off it ran lumpy and tried to cut out.

Got brake cleaner cleaned all boost pipes no blocks but I can't blow thru the two port boost solenoid is that normal?

Car still runs same splitters etc but if I slowly increase pressure on accelarator it drives fine until u get to 8psi then holds back and splutters.

I give up now

[diffbuster]

Hi there,if the car has had sti ecu and ran ok the injectors have been changed,I think rb5 had 380s standard sti would be 440s if the fuel rails have parallel mod check the routing to fpr.As the guys have said it does sound like a boost leak though I would also try another known good maf as they have been known to be faulty straight out of the box.hope this helps. Gary

Edited November 4, 2011 by diffbuster

[colin_ross]

You need to cover the vent. Without the cover the maf connections get soaks and give the exact symptoms you've described. Does the car live outside?

Might be something else but like I said start with the simple stuff.

[damowrx]

I've fixed the problem. I just re- fit new boost pipes and thrown away bleed valve and cleaned boost solenoid cleaned every plug checked gaps .7 and reset rb5 ecu took it a run spluttered and backfired then shot away up the box no probs at 8psi is that the standard boost setting I take it?

I came back checked all new boost pipes were ok went out another drive and it was perfect sat at 8psi. So I don't know what I've done to fix it but touch wood that's it ok.

Just like to say thanks so much for all your Info

[rig-pig]

nice one m8 i think the standard boost is around that but i could be wrong

[spect]

woo hoo, good on you. Mine runs at around 8.2 psi but is a 2006 WRX so I guess that is about right. If it drives good then that should be ok. If you can ever afford a re-map maybe that would be good for the car too.

[damowrx]

Thank you guys as I was ready to just give up and put my wrx engine in it as its been like that for 3mths. I bought it to restore it as last owner just didn't look after it at all.

I'm more than happy with std boost just now when I'm back at work remap defo happening with FMIC

Thanks again guys

[johnnyr6]

I would get rid of the blitz filter (if its the induction kit) they are very good at killing mafs. Also as playsatan says if you havn't already get a vent cover.

Hope it stays healthy for you.

Johnny

[damowrx]

I've bought new covers on eBay, the last owner drill air box full of holes so I've got one in my shed so you think it's best to replace it?

[spect]

oops I meant .82 bar for normal running and .93 for race map

[johnnyr6]

I've bought new covers on eBay, the last owner drill air box full of holes so I've got one in my shed so you think it's best to replace it?

Ah, so its the panel filter then. Should be ok then. when its time to replace the sti filter is good. As for the airbox, it depends where the holes have been drilled. As long as none are past the filter it should be fine.

johnny.