Jolly Green Monster 2

on an MY96 UK?

Lunchtime and floored it in 4th.. had full boost 0.91bar and then power backed off to 0.5bar and obviously limp home mode..
Stopped and turned off the ignition.. checked ECU history and nothing record.. started car and it is back to 0.91bar.. although I have slowly taken it on boost to check etc..

Travelled about 15miles since and no problems..

I had been giving it lots of stick and it was a cold day so could be overboost.. but does that cause limp home? it might have been knock, as I was behind a car turning right into a slip road and slowed and dropped to fourth.. engine breaking in fourth, then slowly applied throttle and floored it when 3000rpm was dial in..
blue like on Dawes AFR as normal etc..??

I do have a fair amount of oil in the intake so the boost controller could have been a bit slow to catch it and fuel cut?
I dunno.. I keep cleaning pipe work but I cannot fully get rid of it..

Cheers

JGM

Jolly Green Monster

iTrader: (4)

No one??

JGM

P20SPD

iTrader: (1)

Sorry JGM missed this one.

Could be the overboost blew too much vapour into the boost solenoid, which caused the ecu to go into safe mode. Then when re started the checks on startup showed it had cleared.

I dont know, just a suggestion.

In cold weather i personally think it is better to feed the throttle rather than stamp on it

john banks

http://www.ravensblade-impreza.com/m...agnosisegi.pdf

At the end of the manual it gives lists of possible faults based on failure phenomena.

Bob Rawle

It was probably not true limp home, the ecu will drop boost if it sees too much knock retard for too long a period, the earlier ecu's seem to have a similar reaction in this respect to the later ones. If you got no codes or CEL then this was probably what happened.

mutant_matt

Like Bob said, Limp Home Mode means the car running really badly!! It pops and farts, won't rev, won't boost and idles in a very lumpy fashion!

Matt

rosswalker

Could possibly be a dodgy air mass meter. This would cause it to go in to limp mode. They usually "go" under hard acceleration.

Jolly Green Monster

iTrader: (4)

Oh...

Likely too be getting knock then.. doh!!

It is currently running fine in 2nd, 3rd, 4th and 5th but in first there is a loss of boost.. like overboost..

Just changed another coil pack and still the same.. got the other two still original to change.. unlikely to be related to this problem though..

Car is running on Optimax or 97 RON.. ITG panel filter and full decat..

AFR is fine.. perhaps a one off?

Was going to buy a knocklink in the group buy but my job looks a bit shakey so have had to shelve that idea.. but then I don't want a car in bits either...

JGM

Jolly Green Monster

iTrader: (4)

Thinking about it the tickover is at 600rpm every so often.. never stalls though..

Sometimes if it is damp it starts and sounds like it is on 3 cylinders? until warm and then runs fine.. I was assuming this was the coil packs as has done 119,000miles.

Cheers for the info so far, I shall take it easy and keep a check on it.. might be time for tapping that laptop into the ecu to see if the knock is being retarded... TTL to RS232 connector anyone?

JGM

[Edited by Jolly Green Monster - 2/14/2003 10:01:21 PM]

Jolly Green Monster

iTrader: (4)

I know I am talking to myself as everyone ELSE is out doing something romantic..

I took the air filter off to change the coil pack and clean the boost solenoid and cleaned the MAF whilst I was there which was clean already and surprisingly considering the miles unmarked..

If the MAF was going would the AFR read weak?

The AFR does seem to only be useful when the lambda is at exactly the correct temperature though.. If I cruise at say 3000rpm for a few miles the lambda sensors reading is as good as useless..
Pull off the motorway and queue for a roundabout for example and it is back to reading correctly.. I was under the impression this was pretty normal?

Also the exhaust if black.. would hope that the tail pipe would not be so sooted if the mixture was weak for any considerable time?? or am I wrong in thinking that?

JGM

jameswrx

iTrader: (4)

I have exactly the same symptomns mate, watching this thread for some help.

My bad missfire in the morning was deleted by changing a coil pack (went for the hardest to change and it sorted it)

I still every so often get a missfire when i go to overtake something, for instance change to third give it WOT and it misses, then it runs low boost and like you said it also idles low, not all the time just now and then.
Very annoying though.

No fault codes stored either.

Not much help I know but I'm sharing your annoyance.... and I'm on a romantic half time break!

James

RT

Had this once on my JDM STI7 RA.

Wasn't even on WOT or anything. Was slowly easing out of the lag-zone, prob at 3500-4000rpms in top gear trying to overtake a taxi. Just as the boost started climbing past 0.5bar, the KL went to red, the car stuttered for a split second. After that, it wouldn't go past 0.5bar for the next 3mins.

Once I slowed down to 50kmh (highway turn off), it went back to normal. Strangely enough, it did it only this one time altho I've seen det before with WOT on the KL. Maybe this was the only instance severe enough that the ECU picked up.

Jolly Green Monster

iTrader: (4)

I also have a different ECU map.. but will be running it on standard map until I sort this and see how I get on..

Was thinking last night i haven't checked the timing since I started servicing it myself.. about 15k miles so I shall look into checking it..

I have changed both coil packs on the drivers side and will do the other two this week..

I don't think they are related to the 0.5bar problem but I shall change them anyway.

Also plannig to change the plugs.. again unrelated I suspect but due a change anyway.

It was a cold day and I suspect it was a once off but don't want to risk it..

JGM

Pavlo

Okay, so now 2 people with the same problem running on similar (but not the same) ecu maps, boards were from different sources.

I've never seen this on my car without being able to read an error code, and it's this that confuses me. I went through a stage of getting idle control valve errors, which I think was me lugging the engine at 500rpm moving in traffic.

This has given me some food for thought, and I have something in mind to try in the near future.

Odd that both people affected have been changing coil-packs recently.

Paul

Jolly Green Monster

iTrader: (4)

I'd just like to say that I am not pointing a finger at the ecu map.. just this is the method used for the high boost on my car etc..

I think I had an inlet manifold leak for a while on my boost gauge connections.. so I think I was not running full boost 0.9bar for a while so I think now I have no leak and have everything working fine the car is boosting to 0.9bar and this problem is raising it's head.

Although it only dropped to 0.5 once it does feel a bit restricted at WOT.. goes like stink but seems to hold back at high rpm but I could be imagining it.

JGM

jameswrx

iTrader: (4)

yeah i'm gonna put my ecu back to standard and run it for a while to see what happens, prob tommorrow now because i've been busy fitting new d/p and me back has gone into 'limp home mode'

Trout

iTrader: (1)

On early cars I think there are two additional possibilities.

However - did you get a flashing check engine light - this typically is linked to going into limp home mode.

One possibility is a very tired Lambda - there is a voltage within range - but it is very wrong. I have seen this on a MY93. Made the car behave very oddly - once replaced everything was fine - however there was no CEL code for failed Lambda as the voltages were within range - just at the wrong time!

The other is a failing MAF circuit - again - you may not get a CEL error code - but it can make the car behave very strangely.

One thing I would say - it is worth refitting all the sender connectors just to make sure all the contacts are clean - and also do the earthing mod. Doing this transformed the running of my car - much smoother, cleaner running and quieter. Certainly worth the effort.


It could be worse tho - a friend had a similar problem - went into limp home - called a Scooby tuner who told him it could not be driven and then charged him £200 for the rescue.....hmmmmmmmmm!

Rannoch

Jolly Green Monster

iTrader: (4)

James,

When I fitted my ecu adaptor I cut J1 and put a wire on either side of the resistor to a switch.. so I can switch from adaptor to normal map.. makes swapping rather easy..

Rannoch,

I thought the Lambda sensor was not used on WOT but the MAF therefore the lambda sensor shouldn't be causing this problem of 0.5bar??
Could well be the MAF...

Connections on the MAF and the MAF looked fine, looking fine doesn't mean it is working though.. AFR would be out on WOT if it were the MAF though?? admittedly I didn;t see what the AFR was doing when it tripped into 0.5bar..

JGM

[Edited by Jolly Green Monster - 2/15/2003 8:38:24 PM]

Jolly Green Monster

iTrader: (4)

Been doing some research... I'd have trouble adjusting the timing!!

I knew the ECU advanced and retarded it but assumed there was a base timing that you had to adjust and check as there is timing marks on the block too... apparently not..

JamesWRX,

Where are you based? just thought if we get into replacing sensors we could go halves and try them on both cars etc??
I'm based in Kent and Derby... Derby in the week and Kent at the weekends....

JGM

[Edited by Jolly Green Monster - 2/15/2003 9:04:37 PM]

jameswrx

iTrader: (4)

JGM, I'm in kent mate, I'm up for trying the maf sensor.

Jolly Green Monster

iTrader: (4)

Does seem the most likely item to be the cause.

Anyone know the cheapest place for a new MAF?

I believe you can get them without the housing..

I'll aim to fit my new coilpacks Monday night.. as I have them already.. I cannot see the MAF effecting cold starting as I believe it is only used on WOT (not 100% sure but I believe this is true?)....

JGM

Dicke C

Megastream did some digging into this and came up with this.

http://www.scoobynet.co.uk/bbs/thread.asp?ThreadID=154601

Hope this helps,

Dicke C

Jolly Green Monster

iTrader: (4)

Thanks Dicke...

JGM

currymonster

Was the MAF on my cousisn STI V swapped it and working like a dream

Cal

jameswrx

iTrader: (4)

I took my module out today and re-soldered the resistor on the pcb, the car still missbehaves so I can elliminate that now.

Mine was running bad in the mornings changed one coil pack (advice from phill venn, barrets motorsport) and it cleared the problem.

But mine missbehaves at WOT so thats why i'm going the MAF route now, apparantely cheam motors will be able to help with the maf (thanks mega_stream). Going to try and order one up tommorrow.

Makes you realise how good the ecu module is when you go back to the standard map!

Jolly Green Monster 2

Agree about the adaptor.. it is quite nice on the switch because when you start thinking it is slow you switch to standard and then appreciate SLOW..

I am about to go and replace the other two coil packs..
my theroy being the spark is not strong enough produced by then at WOT and perhaps causing the tick over low problem.

If I right that the MAF is only used at WOT how would it effect the tickover?

I know it does on the newer cars, are they different??

I'll be back once done etc..

JGM

jameswrx

iTrader: (4)

Tried to order a maf sensor today, grrrrrrr bloody local dealer, gonna try and sort it with cheam motors tommorrow.
Surely they've got one of those projector things with part diagrams on it, even Ford have one

Pavlo

MAF is used all the time.

Now james has ruled out the module, I don't know what else to suggest, perhaps loom problem, possibly related to injector or ignition grounding?

Back firing on WOT suggests lean AFR, but JGM has that covered.

Coil packs seem to be a common factor, they would definitely be affected with more load, and unil someone replaces the whole set, I don't think they can be overlooked.

MAF problems causing a misfire will generally throw an error code (did on mine).

Easy test isfor maf is try and borrow one if posible, as they individual sensors are not available on the older cars.

Paul

Jolly Green Monster 2

James,

Becareful as the MAF maybe for the newer cars in that thread?

Pavlo,

Just replaced the remaining two coilpacks...

All,

Car now has no miss fire in first and pulls like a train.
On normal ECU map is boosts to 0.75 and backs off to about 0.7bar which is holds to the red line.. in all gears give or take a bit.
I have never had my boost gauge this acurate so not sure if that is normal but I think it is.. my other Scoob was similar but had a PSI gauge so hard to be sure with the figures being correct..

The Adaptor ecu code.. boosts to 0.91bar like normal, but holds it right to the redline in every gear!! which is was not doing before it was backing off to 0.75 / 0.8bar etc..

Managed to spin both front wheels.. whoops.. and first gear has never pulled this strong.. catching 2nd before the redline harder etc..

Wicked....

But tickover still at 500-600rpm on occasions????

I did about 5miles so will see how she goes tomorrow.. but it was very cold and I have had problems in the cold previous on the same test drive and it was great tonight..



I shall have to wait for a damp morning to be sure that the lumpy miss fire has gone in the wet.. but I am happier with the go..

Not sure if my inlet manifold has a leak or not.. I took a pic which I shall put up later..

MAF all the time?!! oh...

JGM

Jolly Green Monster 2

Most unusually Scoobynet seems to be zipping along and everything else at a very slow pace so no pictures uploaded yet as turbosport seems as slow as a dinosaur..

JGM