bit of a long one peeps but any help would be great.
right i have a 93wrx it has a simtek,fmic,550's,apexi filter, parallel fuel setup,fpr,td05.
it started to smoke so i was thinking rings,so got another car for the engine that had been rebuilt by triton.
anyway fitted it in mine with the td05 that was with it. got my mapper in today and he set up and we went off.while giving it some he said my injectors were at 100% by 0.7bar.
now why would that be??????
ive only changed the long engine and turbo and used my inlet n parallel rails,
surely my 550' wont max out that early??
the injectors are yellow but bought them off here as 550's.
my mapper said to plumb my defi oil pressure gauge into my fpr to make sure the pressure is rising with boost. will this tell me if my fpr is fooked???

any ideas people
got me right stumped

 

there 440s i think mate i got yellow 440 injectors for mine

 

thats what i thought but it was mapped with them before on the old engine and i got 1.2 bar and he didnt say they were at 100% then.

 

Could be a million things to be honest mate....... My car was hitting 97% duty cycle at 1.3 bar on my TD05 18G because the waste gate couldn't support the boost and was leaking, so the car had been mapped to it's theoretical limits but it wasn't at it's limits if that makes sense....

Changed the wastegate and all was well

 

What pressure is the reg set to?

What fuel pump is fitted?

 

3 bar and a walbro 255.

 

Sounds like reg failing, fuel pump, or filter. You need to fit a gauge, inline or other.

 

the reg has a gauge,but im going to plumb my defi into it to make sure its rising right. the walbro is less than 10 months old and the filter is a aftermarket 1 not an subaru 1. do u think it may be the filter,ill put on a oe just incase.

 

Can be any of the above, check the reg is holding pressure with IGN on, i.e. with fuel lines primed it should maintain pressure after priming, if it drops fast most likely the reg is failing.

 

right plumbed in my defi and turned ign on it primes then drops out. does that mean it fooked? because it stays at 3bar wen engine is started. it also rises with boost.

 

Fuellab FPR is what you need - havent seen one of those go pear shaped yet.

Cheaper ebay FPR or lookalikee ones always seem to cause problems.

 

have you got 1 for me duncan, you could let me have my bbs discount

 

lol - I am afraid I dont carry stock of them.

I know Mark at Lateral Performance has them on special offer at the moment though

 

 

This could be one of several things and I had a recent experience that was rather baffling.

Firstly let me say that yellow injectors are normally 440cc and operate at standard fuel pressure to around 320-340 bhp whereas 550cc injectors will operate to around 400 bhp. If these injectors previously operated beyond their present ceiling the problem will lie elsewhere.

On the rollers at Scooby Clinic on the STi 3 Wagon (standard pistons etc 422 bhp) we noticed fuel was dropping off at the top end. I fitted an uprated fuel pump, the problem persisted and I concluded it had to be the FPR. That was replaced when I returned home, 120 miles and the following week it went to a rolling road day at TEG Sport, 85 miles from here. The car ran perfectly on the way there but as we were in convoy there was no need for WOT. The car went on the rollers and I was anticipating 422 bhp but we were unable to carry out the run because there were obvious fuel issues and bad misfires.
After the RR session I put the car back on the rollers and Steve Simpson jacked up the injector duty cycle by a factor of about 50% but we still had a top end fuel issue. Driving normally without WOT and observing the wideband AFR guage I drove home another 85 miles. Having replaced the fuel pump followed by the fuel pressure regulator I knew nothing had changed there but when I removed the fuel pump again I was fortunate to find that the rubber pipe connecting the fuel pump to the hard metal pipe as part of the fuel pump carrier assembly was disintegrated inside. It had not been in that condition when the fuel pump was replaced at SC although we may not have examined thoroughly and I can only conclude the pipe became progressively worse over a short period of time to the point that fuel flow was being seriously restricted at higher power. Pipe replaced. Original map back in and all OK.
Good luck finding the fault.

 

thanks harvey.great advice mate.the only thing different was the filter,so ive ordered a oe 1 and im getting a new fpr so im hoping this will sort it, however i will look at the pump as well.

 

if its holding pressure when running and rising 1:1 with boost then it is definately a flow issue,

maybe similar to harvey mentioned or just as simple as a blocked filter.

 

I would also check for a leak to the MAP sensor, it could be that the ECU sees 0.7 bar but the true boost pressure is much higher. The main thing is to eliminate some variables, obvious one being fuel pressure, second being actual injector size as there are 4 types of commonly available yellow side feed injectors:

Standard v3/4 440cc
Standard v5/6 440cc
USDM 2.5 505cc
Nismo 555cc

 

I have a used spare pump here you can borrow for the cost of the postage but it doesn't sound like the pump to me but when I ran in to this problem I had to eliminate the possibilities one at a time.

 

An engine built by Triton in Dorset? Good luck with that dude.

 

YEAH GREAT COMMENT MATE as if i aint got enough problems......