pots

iTrader: (1)

i have a v4 sti and when under ' hard ' acceleration the engine cuts for a split second then is ok ? throws you forward in your seat !
any ideas ??

scoobfan

Your hitting fuel cut mate.

It's to save you blowing your engine basically, I would take it to a specialist
and have it looked at.

Rob

pots

iTrader: (1)

i only seems to happen at about 5k though

Bubba po

Possibly a failing MAF sensor? I'd get it checked out.

Alan MaC

Does the orange warning light come on & stay on?

Jonno_johnson

Yeah as suggest get it checked out, as if its a failing maf, your engine could be the next thing to fail.

pots

iTrader: (1)

no light comes on !

pots

iTrader: (1)

oh no now your scaring me , who's the best specialist ? im in east sussex!

Bubba po

Don't panic, just don't drive the car hard for a bit!

jonathan100

do you have a funny idle? if so i'll bet money it's the maf. just dont bring the car on full boost till you have had it looked at. new maf will prob cost you £80ish 5 min job to fit.

Bubba po

Not for that year, I don't think. possibly £250-ish?

Alan MaC

The reason I asked the question was mine did.

I had changed the Pill in the wastegate to a smaller hole, it overboosted and cut out at around 5-5500 rpm, then the orange light cam on.

I had it remapped at Powestation a week later and no problems.

They reset the fuel as mine was running too rich.

Nver looked back. Goes like a brown thing off a Garden implement!!

Good Luck.

Alan MaC

BedHog

www.xtremescoobies.ltd.uk

Not on your doorstep (Essex) but a reasonably close specialist - I travelled down from the Midlands to use them and was very impressed.

pots

iTrader: (1)

ok thanks guys

donnas roo

my 03 STi had the same problem sent it in under warrenty 11 times in the end they swapped ecu and found it was a piece of dirt on connection,its worth a try before u go and fork out a small fortune.

pots

iTrader: (1)

i've just read on the sidc.co.uk site common problems and one is waste gate solenoid? this is the write up on it !
do you think this may be my problem as i seems very similar but my car is a 1998 model ??


3.2 Waste gate solenoid
The 1997 specification lowered the turbo boost pressure from 1.0 bar to 0.9 bar. The engine breather system vents into the air intake and it is possible for the oil and condensing, burnt oil vapours build up in this valve. This valve is a safety device for detecting overboost and will cause fuel and ignition to be cut if it senses that 1.2bar (97/98 models) has been reached. If it is bunged up, it isn't sensing correctly and will shut down the engine under high boost conditions. The solution advised by Subaru France was not to fill the oil up to maximum but to leave it at half filled only.

If your wastegate solenoid does pack up, the fix is to pull the T shaped supply hose off and fill it with brake cleaner from an aerosol. Then go for a blast before the cleaner evaporates. Tippex thinners also do the job. '98 models have a revised part, which is three port sensing and there have been no reported failures. You can get '97 cars upgraded.

Apparently the fault often occurs just after a service when the oil level may be slightly too high. The 1998 specification engine apparently has revised sensing locations, to over come the above problems but there have been some reports of failure on early '98s.

Sometimes this fault is incorrectly termed as "over boosting". The sensor is designed to detect an over boost situation and is usually so sensitive in normal operation that 1.19bar = ok and 1.20bar = fuel cut routine due to over boost. When it becomes contaminated by oil, this is lost and the sensor can cut in at much lower boost values, cutting in the routine under normal hard acceleration. The effect of this routine is quite disconcerting as all engine power is suddenly lost with some drivers reporting it feeling as if they have just driven into a brick wall!

what do you all think ?
regards steve

prince_of_tokyo

sounds like the car is in safe mode if it doesnt rev over 5k...is your speedo working fine???

Alan Jeffery

Another one is "boost creep" caused by a small hole in the wastegate actuator diaphragm. The result is a gradual increase in boost resulting in a high rpm fuel cut.

briforbes

I had this problem last week.....

The boost solenoid had clogged up due to me overfilling the car with oil when I carried out the last service. You're hitting fuel cut...the check engine light didn't come on when mine did it either. It's unlikely to be the MAF sensor, they're apparently quite hardy on these cars. If you want to test the MAF anyway, unplug the MAF connector when the car is warm. If the car cuts out, the MAF is fine, if it continues to idle, it's knackered.

Check your oil, if it's at the max full level or over, drop some of the oil out to bring it under the full level. Disconnect the pipes from your boost solenoid and spray some carb or brake cleaner into them. Next, contort yourself under the steering wheel, where you'll find 2 green connecters. Plug them together, and turn the ignition to "on", but don't start the car. You'll hear the fan and some other bits working away. Spray the carb/brake cleaner into the boost solenoid until it's clean and noisily clicking away. Put the pipes back on the solenoid, bolt the solenoid back into position, unplug the green connecters, and go for a drive.

Should solve the problem, if not, take the car to the garage.

Merry Christmas!

Bob Rawle

Morning all, forget about boost creep and all that malarky, as just posted the most probably issue is oil contamination of the boost control pipework, restrictor and solenoid. Clean as described, Halfords sell the brake cleaner aerosols, that should fix it.

These cars have a three port solenoid as std.

Maf ... its a hot wire not a hot film.

Actuator problems are the last thing to consider.

best regards and merry Xmas.

bob

wideybrook

Better advise would have been to check the oil contamination first and then boost creep, both are possibilities.

Lee.