Right people i really need help urgently with this one.

1995 sti v2
HKS FMIC
Apexi induction
550cc injectors
Apexi Power FC mapped to 1.5 bar
Gruppe S v2 headers and up-pipe
FSE Reg & Walbro Pump

Since it was mapped i had a burst 90 degree inlet hose to the turbo which caused it to det badly. I managed not to find it until about a week later after i had driven the car a bit. It has been replaced and i have checked all the piping and there are now no leaks. I have heat shielded the induction kit in an attempt to find out why it is still detting.

Took it out last night and while not moving revved the car and at any point above 5.5k you could hear it detting badly.

I can't understand why it is doing this but as an attempt to see whats wrong i am going to be changing the spark plugs and checking the timing belt is aligned tonight.

Can anyone help or suggest what to look at (apart from the mapping which is another issue!)

Stuart

 

Not an expert (by any means), but have you checked the fuel supply? You don't mention whether you have changed the pump/regulator. AFAIK above 300bhp the original pump can struggle, which could by why you are seeing det above 5.5k. Can you monitor the fuel pressure?

Dave.

 

Hi Dave thanks for the reply.

I am running a walbro with an FSE reg. At idle the fuel pressure is 3.2 bar with vac disconnected therefore 4.7 bar at full boost. I am seeing a drop in the richness as it climbs the revs but only slightly (as monitored with a lamdalink) going from 12:1 to 13-14:1 roughly. I perhaps am getting problems with the FSE? Although i have managed to richen the mixture across the map on the apexi by 5% with limited success.

Stuart

 

your going to 14:1 on boost??

Thats lean!

 

Thanks david glad you popped your head in. My problem with trying to richen the map myself is that i asked for the commander to be locked out so i wouldn't touch anything. Now i find myself needing in!

It is approximate as the lambdalink (therefore the lambda sensor) is not the best means by monitoring the mixture (as you know of course). A wideband is the best.

I have added a cold air feed since it was mapped along with the heat shield and i think it is having the effect of altering the map quite a bit. I was advised to add a cold air feed by the person who mapped it but i didn't know it would have such an effect!

Getting 60-69 knock on the power fc btw! but only above 5.5k

 

I was told that anything above 50 is bad and could be causing damage.

Have you tried to remove the cold air feed and see if that resolves it?

Dave.

 

I haven't tried that tbh because i thought it was the way forward!!

I know it could be causing damage but i am trying to check to see if what i am doing is eliminating the det.

I think i need to get it checked by using wideband and det cans like it was originally mapped with.

 

errrrmmm don't do that!!! flip!

do you have access to Settings -> boost?

if so set boost to 0.8bar.. drive it.. do you get knock whilst on boost in gear say in 3rd?

Has nothing else changed on the car?

It is possible it was mapped with the leaking pipe? and no fixed the map is out..

suggest you get it checked out..

Where do you live?

Simon

 

It was just a thought so that you can confirm where the problem is.

And checking is one of those catch 22's isn't it not a nice situation.

Hope you get it sorted soon.

Dave.

 

A cold air feed IMHO wouldn't make the a safe map suddenly start detting badly.

Did you manage to see what the air flow voltage was above 5.5k? Any small leak pre turbo will mean the voltage is low and it will probably det, or a failing MAF could do the same (quite rare on version 2's but the maf is getting old if it hasn't been changed). Or put the commander in map trace and see what load row it hits......

For saftey to drive it you could use the ign/inj setting and add fuel and retard timing a bit so you can do more driving/testing.

Tony.

 

I have an avcr and i have put the boost off just now anyway. Yes i get it in any gear.

I suppose it is very possible it was mapped with a leaking pipe.

I live in Glasgow but i have got the mapper who mapped it booked to check it out very soon.

 

it was maxing the MAF out above 5.5k ie 5v

it has been changed already and i have a spare MAF that reads the same 1v to 5v as it should.

i have already tried adding fuel/retarding timing with very limited success ie it lowers the knock only a little.

Many thanks for all these replies they are really helping

Stuart

 

Andy F I hope?

 

If it was Andy that mapped it orginally i would expect him to have noticed the low MAF readings from a leaking inlet pipe. When mine was leaking it was so obvious..... so i'd rule out an orginal leaking inlet map.

Sounds like a definate fuel supply problem.... so if its FSE then all 4 injectors will be flowing low, but it could be one knackered injector? Take all the plugs out and have a quick check. Should be obvious if one injector is knackered.

Tony.

PS did the OBX headers go... missed a set on ebay last week that went for £150 just down the road in liverpool

 

I am not blaming anyone here btw. I took the plugs and changed them tonight for new ones (PFR7B's gapped to 0.6mm) and they are all the same and nice and sooty!

As far as the fse is concerned perhaps it is time to invest in an SX?

Do all fse's have a problem of flow or something?

Stuart

OH btw still got the obx headers and up-pipe still want them?

 

SELL, SELL, SELL!

Was going to check the timing belt on it tonight, just see if it was out, but looking in the engine bay, eveything was there and needed more consumables, than was available, so will need to leave that just now.

I'll put it down to the FSE myself, but expecting something to appear some day, in the way of damage to the engine. A bad experience myself say's this, but it may not be the case. Running the car with the split just ain't good at all.

 

It didn't sound like you were dishing out blame so i wouldn't worry

The FSE has become an easy target if problems occur, but i know of a good few that have been on cars that are still running strong (all less than 5.0bar peak pressure as recommended).

Do you still have the oem reg... may be worth trying to temporarily plumb that back in. The fuel pressure will be a little lower than the FSE but it will be consistant. You could change the injcetor setting (increase the %) on teh commander if that isn't locked to compensate.

Tony.

PS PM me a price for the headers please (are they lagged?)

 

Guess you are using Optimax ?

Try some Scottimax or octane booster tosee if the det is reduced.

Not a problem really if the MAF maxes out at high revs, mine does and the revs above that were manually mapped for safe fuelling during mapping .. my MAP is also saturated at 1.14 bar yet it is safely mapped to 1.65 bar.

It is well known that cold air kits lean out the mixture and could be the problem of det, swap it back to what ever you had before and see if it dets less.

If the car was mapped with an inlet leak after the MAF, the mapper would have ensured the mixture was right even if airflow reading ex MAF was a bit off ( based on wideband lambda ) and now would run rich if leak fixed.

The kmock you mention is high, wht do you get in 5th going from say 2500 rpm to 6000 rpm, and under load in 4th between 4000 and 6000 rpm / ( Don't bow it up trying to see! )? Really need det cans to check. get it back to the mapper if all comments above fail!

 

IIRC Stu has tried upping the fuel pressure on the FSE and it didn't change anything inc the Lambdalink readings.

 

Nope don't have the OE one!

PM on its way!

 

I have angled the cold air feed away from the filter and it reduced by 20 knock so i guess the feed may be having an effect although i wouldn't rule out the dreaded FSE !

 

I have a couple OE ones, if YOU wanna have fun fitting it?

 

**** that job again! Rather poke my eye with a needle than scrape my knuckles doing that. Not unless you wanna do it

 

You don't have to bother bolting the reg back on the rail, just take the FSE off and put the OEM in its place. Same 8mm push on fittings, may need a tweak of the lines to make it fit but shouldn't be a big job.....

Tony.

 

Oh ok that makes more sense now! Perhaps i will steal one off of drb5 but then again one of them probably is my old oe one anyway!

Stuart

 

I'm not an expert by any means but I've been looking at getting an APS CAK and done some digging on here and most of the replies are that it should get mapped after fitting (think you said it was put on after Andy mapped it?)

As diverting it reduced your knock a bit I'd concentrate on that first maybe?

Might be talking b0llocks of course !!

 

I agree bollocks! LOL

Seriouslyi know this now but i was advised to do it after it was mapped. Who said Andy mapped it anyway!

More power Scoty!!!!!!!

Stuart

 

That'll take about 6 weeks......

 

The APS is a very diffrent animal to most induction kits tho. The Apexi has a setting for an induction kit in the menu, i presume this has been selected. And from the way i read it Stuart had the induction kit already fitted, it was then mapped but since then he has added a pipe to duct cold air to the kit.... or am i now talking b@llocks

Personally i think the induction kit isn't the problem..... he's maxing out the MAF voltage, i'd expect that to be low for a problem to exist.

Tony.

 

Yes Tony i have the Apexi induction and it has been mapped and selected on the power fc. You ain't talking bollocks my friend.

Yes my MAF is reading from 1v on idle to 5v on max boost/revs so no problem there. At least the Apexi doesn't try to cover up MAF problems like the OEM ecu tried to do!

Stuart