BC5 - A few wee niggles - boosting problems-brake sensors

[slystiguy]

So I got myself a 91 rs legacy. Nice an tidy just a wee project to keep me busy and have fun in at this stage. I\'ve got this strange problem with boosting which I haven\'t looked into much yet (owned less than a week)

So car cold/luke warm - Runs mostly fine. occasionally idle spikes but not constantly or anything. Boosts a bit laggy hits boost at around 4 and goes fine to the redline (Note I only tested this to check I do drive my car like that cold!)

So car warm/hot - Idles perfectly and no issue. But when boosting it will just start to build a couple PSI and then just bog and backfire...

My first thoughts are obviously injector blocking, fuel pump failing or coils failing. Which is the best to start with and how do I test coils/fuel pump ? Another thing that crossed my mind was the factory downpipe is still on the car at 247kms. This could be blocked at that age?

Is injector cleaner worth buying or am I wasting my time?

How do you test a coil ?

How do you test a fuel pump? And I want to upgrade what do you recommend? I see on TM you can get cheap looking ones for 50$ which I guess aren\'t made for turbo vehicles? Walbro was my first choice but I also saw that other branded one on there for a similar price. Thoughts?

In the not to distant future I plan to go yellows/twisted/ecu

Oh and the problem I\'m having with brakes is the handbrake light will randomly stay on sometimes and the abs light seems to turn on when I got over a large bump which is everyday in CHCH. Would that be a lose sensor issue?

[Guest]

If you run a line direct from comp to gate what does it do cold and hot?

[slystiguy]

OH good thinking I\'ll try that tomorrow! Will that will tell me if the turbos/solenoid naffed or not ? It doesn\'t throw any fault codes but I did notice the solenoid doesn\'t tick like my old sti used to

[Guest]

It will tell you if its a hinky boost solenoid/that side of things or not. Cant see it being a turbo issue.

[Roo]

Light might be handbrake adjustment or low brake fluid.

Re the choking under load, I would be suspicious of the afm but wouldn\'t jump straight to it

[filthyrich]

I\'d check the coilpacks for cracks.....

[slystiguy]

Seems to have fixed itself with new 98 petrol. God knows how long it\'s been running on 91/really old lawn mower fuel? I once put 91 in my sti never had any issues like that! Only had the car a week so will give it a few more tests before I can determine it fixed... then will come the upgrades haha. Also the brake light thing seems to be intermittent so really puzzled as to what\'s causing it. Fluids at normal level.

Oh and when you check coils are you just looking for cracks? Or can you test them with multimeter to determine if there\'s an issue?

[oldscoobyturbo]

these cars like good fuel ask me how I know.

visual inspection of the coilpacks is straight forward. if you suspect that these might be original then its time to replace them.

I have a spare set for when mine need changing

[bc5rs]

i if its bacfiring then theres fuel and air id say noones looked at the sparkplugs or coils in as they will break down at temperatures ,my bc5 coils worked fine but i pulled them out and i was amazed at the cracks in them it was impressive replaced them though br worth doing a decent service that way you have a base to compare anything on if the oil in the box for instance is glitery then well thats pretty self explanitory same for the rear diff

[Dairusire]

 slystiguy said:

Seems to have fixed itself with new 98 petrol. God knows how long it\'s been running on 91/really old lawn mower fuel? I once put 91 in my sti never had any issues like that! Only had the car a week so will give it a few more tests before I can determine it fixed... then will come the upgrades haha. Also the brake light thing seems to be intermittent so really puzzled as to what\'s causing it. Fluids at normal level.

Oh and when you check coils are you just looking for cracks? Or can you test them with multimeter to determine if there\'s an issue?

So I\'m curious. Has it fixed itself, now that your running 98? Honestly I don\'t know why people would run 91 in a car like that??? At the best of times it would get detonation on 95 !

[slystiguy]

Well when doing spark plugs I noticed 3/4 coils are cracked. Looking into doing the GD coil pack mod so will probably do that when I get the new twisted. I\'ve been running waste gate pressure for the last couple days and it hasn\'t done it at all. I\'ll hook it back up and run the higher boost soon to see if it still does it. Onto my 2nd half tank of 95 now so will be interesting to see. Could be a failing fuel pump or just the cracked coils. I\'ve got 2 good coils to replace them for now but still on the hunt for a 3rd haha

[rslegy]

Personally i wouldnt even bother with the twin bolt coils. I have changed my to the 3 wire b4/ wrx 1s and i havent had a misfire issuse to date and it feels stronger when on boost

[CUDDAS]

 Dairusire']

[quote name='slystiguy said:

Seems to have fixed itself with new 98 petrol. God knows how long it\'s been running on 91/really old lawn mower fuel? I once put 91 in my sti never had any issues like that! Only had the car a week so will give it a few more tests before I can determine it fixed... then will come the upgrades haha. Also the brake light thing seems to be intermittent so really puzzled as to what\'s causing it. Fluids at normal level.

Oh and when you check coils are you just looking for cracks? Or can you test them with multimeter to determine if there\'s an issue?

/quote]

So I\'m curious. Has it fixed itself, now that your running 98? Honestly I don\'t know why people would run 91 in a car like that??? At the best of times it would get detonation on 95 !

funny how there wasn\'t any 98 around back in the day of the BC5\'s & 96 was the norm for turbo\'d cars

[rslegy]

I run 95 and have no problems at all as i got told by an old mechnicthat 98 was for anything over a 1995-6

[oldscoobyturbo]

Here in Canada I can run mine on 98 but when I take it on long road trips I put it 95 and it still runs fine

Change the plugs and switch it over to the newer plug in coils they work better

[bc5rs]

keep in mind hes probably got a better 98 octane than ours in nz we have shit fuel to the point some of our road transport trucks and digger even have to have a extra filter set up to maintain the euro emission standards and not bugger the engines because there tuned on euro fuels (scania-hitachi komatsu-hyundai-mercedes and freightliner all do ,or there fuel filters are nz spec higher filtration level

[Guest]

 bc5rs said:

keep in mind hes probably got a better 98 octane than ours in nz we have s*** fuel to the point some of our road transport trucks and digger even have to have a extra filter set up to maintain the euro emission standards and not bugger the engines because there tuned on euro fuels (scania-hitachi komatsu-hyundai-mercedes and freightliner all do ,or there fuel filters are nz spec higher filtration level

Not so sure youre on the money with the extra fuel filtration thing dude. Thats a dirty fuel thing but not an emissions thing thats more CJ-4 spec oil and ad blue stuff youre getting into for low SAPS EGR/DPF systems.

Btw we sell 2mic racor units to local Toyota lads to retrofit on CRDI hilux/landcruiser.

[bc5rs]

 evowrx']

[quote name='bc5rs said:

keep in mind hes probably got a better 98 octane than ours in nz we have s*** fuel to the point some of our road transport trucks and digger even have to have a extra filter set up to maintain the euro emission standards and not bugger the engines because there tuned on euro fuels (scania-hitachi komatsu-hyundai-mercedes and freightliner all do ,or there fuel filters are nz spec higher filtration level

/quote]

Not so sure youre on the money with the extra fuel filtration thing dude. Thats a dirty fuel thing but not an emissions thing thats more CJ-4 spec oil and ad blue stuff youre getting into for low SAPS EGR/DPF systems.

Btw we sell 2mic racor units to local Toyota lads to retrofit on CRDI hilux/landcruiser.

it makes the differnce in the egr twin cooling trucks because the injectors are very tempermental about what goes through them,for instance a we have to make some trucks relearn there fuel maps to adjust the adblu content in the exhaust du to adblu beingdependant on current exhaustflow ambiant temp pressure etc but either way im still picking its electrical issues hes got

[slystiguy]

gave it a of a go tonight and even on wastegate it\'s still doing it. Haven\'t had a chance to change the worst 2 coils over yet but be interesting to see if it makes a difference. Still want to do the coil swap anyways so will keep eyes open for a cheap set of modern coils

[slystiguy]

Hey so just and update not sure where I left this.

I had 3/4 coils that were cracked. I\'ve had trouble replacing them as it seems no one has them or isn\'t willing to part with them at least. Anyways I managed to get a couple good ones and replaced the worst cracked ones. I then cleaned the intake of the oily residue, replaced damaged boost hoses and put proper metal hose clips on the lines rather than the crappy worn out wire style type. Also replaced spark plugs at the same time. Got it running awesome now! Hooked up the boost solenoid again and holds boost through 1/2/3/4 gears without any hesitation or issues. And packs a nice punch from about 4000rpm. ;D

Still need to replace the 90degree bend as it\'s got that traditional crack on the hose clip turbo side and I wanna replace all the worn hosing knowing how badly worn they are. But for now it\'s running fantastically and I\'m rather stoked it was so easy haha!

On another note... Where can I get silicone water lines for the older legacies ? Scarles doesn\'t seem to have them and trademe I can\'t find them?