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5TH GEAR ENGINE CUT-OUT

Old 22 March 1999 | 12:46 AM
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I'VE JUST RETURNED FROM THE ALPS AND WHILST CRUISING HOME MY 98MY TURBO DEVELOPED A SLIGHT MISFIRE/CUT-OUT WHEN ACCELERATING IN 5TH GEAR. IT FEELS LIKE THE REV LIMITER ELECTRONICALLY CUTTING THE ENGINE BRIEFLY, ALTHOUGH YOU CAN DRIVE THROUGH IT IF YOU'RE BRUTAL. IT OCCURS WHEN USING PART OR FULL THROTTLE, BUT NOT UNDER LIGHT THROTTLE, AND USUALLY OCCURS AT AROUND 4,500 RPM. THE CAR IS BOOKED FOR 7,500 MILE SERVICE TOMORROW, HOPEFULLY DEALER CAN IDENTIFY/RECTIFY. ANONE ELSE SUFFERED SIMILAR PROBLEM ?
Old 22 March 1999 | 04:18 PM
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When i bought my car the plugs were badly worn and gave similar symptoms.
Old 26 March 1999 | 04:02 PM
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I get exactly the same problem in 4th and 5th. Tends to happen more if i floor it from low revs than if ive been screwing it up through the gears. I assumed it a slight flooding/ fouling problem but it seems to cut power back in instantly.
Can anyone confirm this is plugs ? Its done 25k on the originals ( i think, havent owned from new). It really annoying and on a sweeping left hander on the Mway recently proved to be very scary. Its a very violent cut in power and it nearly threw the back end around.
Old 27 March 1999 | 03:52 AM
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According to the FAQ they should be replaced every 15k, so it might be worth getting them checked.

Cheers, Mark.
Old 29 March 1999 | 02:36 PM
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Oli, had any luck resolving this over the weekend ? Ive been thinking (unusual i know), if the problem was a spark plug wouldnt the engine lose a cylinder rather than all power ?

Mark, was yours dropping a cylinder or cutting out all power ?

Cheers Dave.

I'll get some plugs ordered just in case.
Old 29 March 1999 | 06:17 PM
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DAVE,

YES THE PROBLEM HAS BEEN RECTIFIED BY THE DEALER (LANCASTER, SEVENOAKS)- ALTHOUGH I HAVEN'T BEEN ABLE TO THROUGHLY TEST THE CAR SINCE.

BUT I'M NOT ENTIRELY SURE WHAT THE PROBLEM WAS. IT DEFINATELY WASN'T DOWN TO THE PLUGS THOUGH - SERVICE MANAGER DID TRY TO EXPLAIN (BUT I WAS IN A HURRY, TYPICALLY) AND AS FAR AS I REMEMEBER THEY REMOVED THE OIL PIPES AND FLUSHED THROUGH THE SYSTEM/INJECTORS. BASICALLY THE ENGINE MANAGEMENT CHIP WAS GETTING FALSE SIGNALS OF AN OVERBOOST OF FUEL FLOW (WHEN THE TURBO WAS SPOOLING UP) AND ELECTRONICALLY CUTTING THE POWER.

SUBARU ADMIT IT'S NOT AN UNCOMMON PROBLEM AND ALL THEIR DEALERS ARE AWARE OF 'A FIX'.

HOPE THIS HELPS.

REGARDS - OLI.
Old 31 March 1999 | 11:40 AM
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Doh - wrong again
Old 31 March 1999 | 01:40 PM
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Olis fix was the correct one. Ive spoken to the Dealer he mentioned in Sevenoaks (exceptionally helpful, knowledgeable, prompt AND returned my call) and i also called Subaru UK. They both concurred that the fault has probably resulted from an oil overfill and needs various pipes etc flushing out. Booked in next week in CVC cardiff to have the work done. They didnt seem to recognise the symptoms, looks like they need web access to SIDC :-)

ps why arent my smilies coming out like everyone elses :-(
Old 31 March 1999 | 02:03 PM
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Dont use the - in the smiley just use the colon and brackets and all will be well
Old 31 March 1999 | 02:15 PM
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As an addendum - when Pete Croney was doing the first serivce on my STi V - he said that he wasn't filling the engine all the way up to the max as it caused problemswith over filling, he only filled it to halfway tween min and max.
Old 02 April 1999 | 10:28 PM
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I have an Sti series 2 5 door. It has just been serviced and, I believe, over filled with oil. I now get the same symptons ... engine cutting/missing/detonating!!!??? as soon as the boost hits approx 0,7 bar. Would this be the same problem ? Is the "flushing" something that a dealer has to do ?
Old 03 April 1999 | 07:52 PM
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I get the same problem with MY98 at 3.500 KM and my dealer could not locate the problem. So, an engineer from Subaru Germany came to solve the problem with the limiting of the maximum boost output to 1.15 bar. He told me that even then the turbo sometimes puts a higher pressure nearly at 1.20bar, the pressure when the wastegate cuts off the engine.
I've lost a little bit of aggressivity but on the dyno the engine puts still 219PS.
Old 06 April 1999 | 02:33 PM
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DAVE, ET ALL

'THE FIX' DOESN'T WORK, WELL NOT FOR VERY LONG ANYWAY.

300 MILES LATER AND THE PROBLEM HAS REOCCURED, NOT ONLY IN 5TH GEAR, BUT IN ALL GEARS BAR 1ST AND 2ND. MY DEALER LANCASTERS SEEMED CERTAIN THEY HAD SORTED IT, BUT ALAS NO. ANYWAY THE CAR IS GOING BACK TO THE GARAGE TOMORROW FOR FURTHER TESTS, ETC. DO YOU THINK THAT CHANGING THE ECU WOULD HELP ?

MUCH AS I LIKE MY IMPREZA, IT'S BEEN NOTHING BUT TROUBLE SINCE DAY ONE AND FRANKLY I'M LOSING FAITH.

ANYWAY HERES HOPING....PRAYING ?

OLI.
Old 08 April 1999 | 02:44 PM
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Oli, sorry to hear its giving you so much grief Please keep the thread updated as my car is out of warranty. I dont want to get hit for a "fix" that doesnt work. I am assuming of course that your getting this work done under warranty.
Old 08 April 1999 | 03:30 PM
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DAVE,

IN ADDITION TO PERFORMING THE 'FIX' AGAIN LANCASTERS ALSO FITTED A NEW ''DUTY SOLANOID VALVE''. THIS SEEMS TO HAVE SORTED IT....FOR THE TIME BEING.

I MAY BE WRONG, BUT THE CAR DIDN'T FEEL QUITE AS EAGER TO ACCELERATE ON THE WAY HOME LAST NIGHT. PERHAPS I'M PARANOID, BUT I HOPE THEY HAVEN'T ADJUSTED THE BOOST SETTING.

BEST OF LUCK,

OLI.
Old 09 April 1999 | 06:55 AM
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Hi everybody
PLEASE HELP!!!
I've got also motor cut-out (on all gears but in fact it appears in 5th gear and extend to all gears now on MY94 ).
Note that it's also when you suddenly go under boost pressure that it occurs (if you push gently the pedal to reach the pressure there's no problem) and in worst case (IMPORTANT) I GOT A COMPLETE IGNITION CUT-OUT during around 3 seconds (means that the rev's pointer immediatly reach zero during this time).
Everything has been checked (dump valve, sparks plugs, pump fuel, etc...OK), just the waste gate or maybe the air-debimeter(just after the air box) should be checked at the moment.
Is one of you already got this symptom of a complete ignition cut-out ?
and does the waste gate or the debimeter could do that ?

Old 12 April 1999 | 06:24 AM
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Hello guys

PLEASE HELP!!!

I've got also motor cutting at the moment and it's not fix.
The particularity is on worst cases a complete ignition cut during approx 2 seconds (means that the rev's needle goes suddenly at 0 during this lap). It occurs when you quickly go on boost pressure. If you increase with a light foot there's no cut.

Did someone got the same symptoms because with have test a lot of things(s.plugs, pump fuel, dump valve, electronic,etc...) just remain the waste gate and the air-debimeter...
Old 12 April 1999 | 06:45 PM
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Fred, and everyone else for that matter,
Same symptoms, and if anything slightly worse since a full service last Friday at PTS in St.Albans - including new NGK Sparks and a Ramair. When I first posted something about this a couple of months ago, I was given the impression that it was worn sparks, but alas certainly not - floor the throttle in any gear and get a nasty jerky acceleration as if waves of power are coming through then tailing off suddenly, to the point on Sunday where the rev counter needle momentarily whizzed to zero and back again - bizarre. I am going to ring PTS tomorrow to see if they have any ideas. Daft thing is, they told me mine was one of the best running WRXs they have had in. SOMEone out there must have sorted this out - its really ruining my fun, to the point where I'm delaying the purchase of a Scoobysport backbox in case it costs me wads to rectify. I'll check my oil levels tomorrow.

Cheers,
Zip ('93 WRX)
Old 12 April 1999 | 10:15 PM
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Here's a REAL long shot to those losing ignition. I had the same problem on my current car (MR2, Turbo arrives next week). Turns out it was a fault in the imobilliser system cutting the ignition every now and again. Caused the same symptoms as described.

Tenuous I know, but I hope this help
Old 13 April 1999 | 10:14 PM
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I had exactly the same problem on my MY98 from nearly new ( first occurred at 600 miles ) anyway after 3 trips to dealers with the following actions -
1.flush hoses ??
2. replace duty solenoid
3. re-flush hoses
it was apparently diagnosed as a a slug of oil \ grease with some plastic swarf thrown in for good measure causing intermitent blocking and overboost.
this seemed to cure the problem ( 7500 trouble free miles ) and as I have now had a superchips conversion ( very impressive even after 2000 miles ) I am told it should not re-occur as overboost feature is defeated
Old 14 April 1999 | 06:28 AM
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Paul, if there's something to flush, can you give more info : what exactly was flushed ?
Wich pipes or other things have to be ?
Old 20 April 1999 | 06:01 PM
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hmmmm. 2 problems? the guys with ignition cut out, and those with momentary total loss of power. I have an MY99 STIV and have had exactly this BUT only when giving it real welly, usually coming out of corners with bags of throttle. Never happens unless I'm "having some fun". I suppose I've kinda solved it because it always happens when I'm running low on fuel - therefore a limiting fuel delivery thing anywhere between the tank and the injector pump. Just a thought - but maybe some of the probs above only happen when tank partially empty? (well, the engine ctout without the ignition cutout ones anyway)
Old 22 April 1999 | 11:37 PM
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This sounds familiar..I have only experienced the engine cut out under full power on me twice, and on both occasions the car was nearly empty. Out of curiosity I tried to get the car to perform the same trick after filling up, but no dice. Fuel starvation due to sudden acceleration when the tank reaches a certain level? This has only occurred twice in 13 thousand miles.
Old 23 April 1999 | 12:27 AM
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No way guys, in my case no difference with full or empty tank. Anyway the fuel pressure has been checked while running OK.

What the hell...
Near that every parts have been exchanged and I always got this complete ignition cut-out during 2 seconds when calling quickly the boost pressure.

Anyone idea ? Does a faulty spark plug self
can do a complete ignition cut-off. I believe it should be like running on 3 cylinders in this case or I'm wrong?
Does a faulty fuel injector can do this???

Thanks for any help
Old 23 April 1999 | 05:07 PM
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PTS has had mine in today. They have replaced the sparks (again) and checked the gaps. Boost is running at 15 psi which they said was a bit high (is that about 1bar?) They took out the replacement Ramair, as they said this could be causing it (eh??) and tried a K&N - said that was a bit better. Do I HAVE to use NGK PFR8s???? So they are going to have another look next week (ran out of time today) and they have put in some temporary boost limiter in line until they have it back. God, these turbos are a black art. Give me a good old twin carb'd pinto anyday.

I shall keep you informed - I keep mentioning a fouling of the wastegate solenoid, but I don't know if they've looked at it - can I clean this out myself? If so, where the hell is it? I know the FAQ mentions a T-shaped pipe, but WHERE???

Regards, a still pissed off Zip
Old 23 April 1999 | 07:14 PM
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I have a MY'96 5 door Sti. My car starts to cut out when ever the boost gets to 0.8 bar in any gear. Everything has been changed, mass airflow meter, plugs, map sensor, temp sensor, boost solenoid, ecu !!! etc and still it persists. All pipes have been cleaned/replaced. My dealer has now enlisted the help of a specialist auto electrics company in Bristol (don't know the name) who apparantly are the bees knees with Scubes. Anyway they have had an initial look without success and the boost is currently limited to 0.7 bar by by-passing the ecu and using a bleed valve. Its booked back into Bristol on May 5th for three days so that they can sort it. The only sensor that has not been changed is the knock sensor. One is on order and this will be replaced at the time. So ... I'll keep you posted. This seems to be a fairly regular occurance across the list as far as I can tell and so I'm dead keen to pass back whatever info I get on this. My car has only done 10,000 miles.

What a good job its covered by warranty !!!

Bob
Old 23 April 1999 | 07:36 PM
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If this can be of any help, my Integrale Evo has suffered exactly the same problems encountered by yourselves.

I suspected an overboost shut-down. As main dealers could never rectify the problem I took it to Interpro to put on the rollers. As suspected it was over boosting and the over boost sensor was shutting down the ignition to prevent detonation.

Unfortunately the only remedy was to decrease boost pressure from 15psi which solved the problem. Still putting out 13psi and approx 227bhp in standard form.

No such problems from MY98 Scooby and 8000 miles on the clock.



Old 24 April 1999 | 10:01 AM
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In regards to you guys trying to figure this problem that keeps you running in circles, You all have mentioned some good points but one..A in house drivability test. Its featured on a "dynometer" under an actual load. The computer diagonostic terminal can be applied to the vehicle during the test. Why is this important? well, a couple of things come to mind. one is the turbo and its habit of "cutting out" in 5th gear or any gear for that matter can be caused by a boost control or wastegate controller. Under a "static test" (not under load) the engine cannot develop a gradual boost level. why? because of unihibited horsepower. that means its not "working as you would if you were driving". Im afraid the computer isnt capable of fuzzy logic, or moderate thinking like a person. It operates on "signals" from various components. This "flush" as was spoken of sounded like a techs way of saying..washing my hands during the test. Im sorry, but the only way to really diagnose the problem is "REAL TIME TESTING UNDER A DYNOMETER". All of you seem flustered, but I know subaru makes good cars, they sometimes have a glitch that develops. Id imagine that a "faulty signal" or inappropriate computer subroutine may be at fault here. One thing that I know for sure, as parts age, sometimes, the computer cannot react as it used to. I know subaru installs what they call "aging" in their programming, but it im sure isnt foolproof. Best of luck. maybe some of you can ask your dealer to "dyno it" real time. Ill bet a million they will find the trouble in short order.
Old 24 April 1999 | 03:55 PM
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Hmm ... Thats all to the good Jeff but when the condition stimulates no ecu fault codes and cannot be found using an oscilloscope to trace the fault then it does not matter wether the car is on a dyno or not. I have a boost guage fitted and boost is not cut but it certainly "flicks" when the engine misses. I have some latest thoughts on this. My car has the earlier boxer engine. The one thing that would cause this and nothing could pick it up would be the coil packs starting to fail under elevated temperature and boost. The ecu would fire the pack but if it did not generate a strong spark then the result would be no proper combustion and hence the result that I see. IMHO this could be an elusive fault to find without replacing the packs (£47 each plus vat I understand)

Anyone any experience of this happening ?

Bob

[This message has been edited by Bob Rawle (edited 24-04-99).]
Old 25 April 1999 | 06:01 AM
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That is unusual. I cant imagine an occiliscope not catching this miss you have spoke of. Yes,temprature can cause a occasional "blip" in a coil, but another possibility that comes to mind is I have seen a very unusual thing happen in a coil. The center "core" of the coil can actually be broken in 2 parts. It continues to run, but at a certain rpm range, the resistance can show good numbers on a digital vom, but still be bad. The amp load of a coil varies as rpms fluctuate. The occiliscope may not be able to trace the drop off as its so sudden. when a plug is firing hundreds of times a second, a blip or two isnt bad..but a series of blips..well you get the picture. My earlier info I wrote was based on some other experiences Ive seen over the years. Is it also possible that the crank position sensor is loose? a bad signal could be harmonically active during engine loading. Ive seen alot of things..maybe check there? That may not be caught by the ecm, as its not consistant enough to cause a trouble code.

good luck.
jeff

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