iamrab

hello

right ill try my best and explaine this the best i possible can.
when my99 classic is cold when you drive it down the road taking it easy of course sitting at 45-50 in 5th gear the car is on power off power on power off power even know im keeping my foot at the same position the whole time.

when the car is warm its feel very restrained some times like its holding back,now i was thinking its one of four ..or all four lol

1) air flow meter/maf (was replaced 16 months ago time for another?)

2) cold start valve? (is there one on an impreza?)

3)fuel pressure? weak pump?

4)boost solenoid?


listen any help is very greatful as i dont like when my cars not 100%

many thanks

rab

RON

I hate to say it, but most 99's and 00's seem to do it, if you get one that doesn't, you're lucky!!

iamrab

ron what is this tho? is this just the car or is there an actual fault that i can fix? it only started it last week lol just really strange

andyxros

am sure this happened to mine a bit ago and can remember un plugging lambda sensor and it was beter so bought a new one (cheap 1) and never felt it again as it used to do this on motorway at 80 just on throtle and off boost car would very lighty pulse (bought a OE one just before re map just to be sure as cheep 1 was only to test it) but all cars are diffrent so this is just advise

Skooby53

iTrader: (1)

I had this on my MY99. I fitted a new lambda sensor after it got to the point where it was horrible to drive. It was OK with very light acceleration, but, when I tried to press on a little and the engine was warming up it felt like it was missing and spluttered very badly. Try a cheap one as suggested and see how it goes. You could just unplug the sensor for a short time and see if it improves.

The boost solenoid could also be a cause of this type of problem so that would be the next place to look. A quick clean with carb cleaner and a blast would clean it out. Good luck

iamrab

listen lads thanks for all the help im gonna go and have a look now and ill let you know

many thanks

rab

chris-RB5

It is 100% your lambda sensor, it's doing that because your car is running rich when cold don't bother with a cheap sensor seriously will cause you more trouble that what it's worth, if you can't afford a brand new one would just go to the breakers and get one.

andyxros

think ive seen one on flea bay for a tenner and looks like an OE one. might be worth a look for testing

RON

My car does it when cold, i know lots of 99's and 00's that also do it, i have always put it down to the fact that when cold, the ecu is effectively running the engine with choke, ie, using more fuel.... if you've ever driven something like an old Mini, you'll know the feel of an engine running on choke, Scoobs will do this until the temp sensor tells the ecu the engine is warm......

I'm 100% sure it's not 'my' lambda sensor, and i would persoanlly doubt that a new one would make any difference.....

I've had my car 8 yrs from new, it did it then, it does it now....

chris-RB5

You know what RON when he says it only started last week there's obviously a problem occured, don't know why people like you come on here just to argue, especially when were trying to help the lad, plus i'm talking from experience as this happened to me and i know a subaru dealer mechanic who advised me to change the lamda and hey presto it worked. But you obviously know more than a subaru trained mechanic don't you.

rigga

iTrader: (4)

Seeing as most subaru trained mechanics are not exactly the best at their chosen game im not sure thats a reasoned argument to be honest,plus the fact Ron has been a member since 2000 suggests he has some experience to fall back on,id also sugest Ron is not coming on just for an argument,but to give his view on the matter,altogether a different proposition........

chris-RB5

so my argument isn't back up with fact then rigga, seen as though this problem occured with myself, was advised to change the lamda sensor and it worked, thus end of story. and what is the harm in iamrab trying a new sensor please in-lighten me, as you seem to be forgetting the point of him coming on here and asking for our advice

RON

Thanks Rigga, i certainly do NOT come on here to argue with anyone.
I am just putting across my opinion, which i think you'll find we're all entitled to do, i didn't say i knew better than any Subaru mechanics, but i've been on here long enough to read almost 100's of threads with people asking about exactly these symptoms, and no-one has EVER come back with a definate answer, my car has even been remapped, and it still does it, if the mappers can't cure it, then no-one will.......

andyxros

its very hard to diagnose a problem by words and a computer screen this is why we all put our opinions on hear for help and advise. people can ether take it or leave it there is no need to argue

chris-RB5

I don't want to argue with anybody either all i'm saying is that this problem happened to myself was told what it could be replaced it and the rest was history that's all, is just the fact how iamrab described it was the exact same symptons as mine. like andy says take it or leave it.

RON

Quite, i didn't type what i typed to get anyones back up, just give my opinion!!

Alan Jeffery

Checking a lambda sensor on a classic is pathetically easy. Just take it to a decent tuner and ask them to do it. It's what we're for you know!

chris-RB5

i'm sorry ron

RON

No worries.....

burt2000

iTrader: (1)

if its that surging/wavy feeling of boost when on half throttle when cold, i had the same prob and have heard its very common....when i had the greddy boost controller fitted its almost 100% cured it, wouldnt be noticeable to anyone but me...

also it eliminated the strange half boost i would get in 2nd gear sometimes if i floored it, kinda felt like was running about 7 psi between 3-5k revs then after 5k revs it would kick full boost again....all probs gone now so i assume it was the oe boost solenoid giving the problems

Burt

DJ_Jon

iTrader: (7)

mine used to do this, Changing the knock sensor has cured this problem.

it started out as hesitation when cold, then the hesitation got worse & the CEL came on & I had it code read, turned out to be the knock sensor - job jobbed

Floyd

iTrader: (9)

As Ron says, it was a feature of facelift classics. IIRC John Banks did some work with the problem and one idea was to bypass the lambda when cold. I never tried this as my car does it too. I use the symptom as a reminder not to drive hard when cold.

New_scooby_04

iTrader: (4)

hang on a minute: 45 in fifth gear? What's that, about 1800rpm; I'm not surprised she feels a bit lumpy! Try 4th!!

Facelift classics are a bit lumpy from cold. If it really gets on your nerves, I find that this is resolved completely after the water temp is up to normal (this doesn't mean the oil is up to temp, so no thrashing yet!!) so just leave it on the drive for a few mins before pulling away and hey presto! If it's really bad, your lamda is prob shot.

Ns04

iamrab

listen lads thanks for all the comments even if there was a bit of loave hate there lol ive tryed a couple of different things so ill report again and let you all know whats happeneing even if its just outa intrest


listen thanks again

rab

iamrab

ok UPDATE!!!!!!

IT ISNT A LAMBDA SENSOR i repeat NOT A LAMBDA SENSOR

replaced it with a brand new one and its still doing the same thing
musta be the boost controller as standard that causes

or

im thinking it could be coil pack,leads or plugs
i fitted a full magnex and milteck down pipe and every now and again
now i mean like 1 if im lucky a day it just gives a quick miss when on full boost ....so im thinking that the coil pack is on its way out .

what you reckon ?

rigga

iTrader: (4)

OOOO,not the lambda then,this could get interesting again lol

iamrab

i could have opened the can of worms again lol

weeebell

iTrader: (1)

Did you try driving it with the Lambda sensor unplugged or did you just fit the new one and try it.
I have the EXACT same problem as you and unplugged the sensor and it ran like a dream so I bought a new one, fitted it and it ran lumpy again.
Dont want to hijack the thread, but what would running the car with the sensor unplugged do to the car in the long run as its seriously doing my head in?

iamrab

yep didnt make any difference at all

Eprom

The My99/00 are prone to this until they are warm, mine has done this from new, and still does it, even with a PPP ecu of that year, I think the fault could lie with the software in the ECU, the second gear low boost was written in for regulations for drive by noise I believe.