naughty

i have had a slight misfire hardly noticable but there, i took it to the garage and they attributed it to a weak signal from the lambda sensor, it was replaced and the problem now is much worse, the sensor is not switching quick enough it is running too rich to long, at idle when cold the car seems as if it is going to stall then recovers itself at the last second, and when youre driving along 2/3k revs the car feels as if its holding itself back or being restrained on acceleration then it eventually maybe 2/3 seconds flies off as it should do and ideas so i can prompt the garage when i take it back in on tues.

thanks naughty

ps 95 wrx, hks filter, de cat, chipped and delimited.

[Edited by naughty - 10/3/2002 8:29:10 PM]

jonny gav

iTrader: (1)

sounds like they put the wrong sensor in mate, do you know the type of sensor they used?

the problem you discribe sounds like a coil pack or plug fault, did they check them out???

[Edited by jonny gav - 10/3/2002 8:34:05 PM]

naughty

they used a bosch sensor so im sure its the right on, will try with the plug and coil pack though thanks

muddy

naughty,

Sorry to Hijack your thread.
I would be interested to know what your outcome is.
I have exactly the same symptoms ( idles up and down, to the point of stalling then recovers and an hesitation upto 2/3k revs then suddenly kicks in), but as yet have not had chance to sort it out.

I thought it may have been the lambda sensor also, but peeps on here (When I posted the sypmtoms the other week) seemed to think that it was something else.

I don't know and am confused, that's why I have left it for the time being.

Hope you get it sorted out.

Muddy

tweenierob

Just a thought for ya..
The Lambda sensor does not give any control on boost, in other words it may count for the poor idle but will have nothing to do with your hesitation prob..
Would bet money its the coil packs
Rob

Fuzz

MAF sensor anyone ?

Andy <clutching at straws>

naughty

no problem with shareing the our sins muddy, does your scoob see to use a lot of fuel? thanks to tweenierob and fuzz for ideas.

naughty

muddy

It has always seemed that it has been a bit of a petrol guzzler anyway, but this appears to be the norm.
I generally get about 200 miles out of a full tank,(well, just below 1/4, cause I don't like it getting too low) which is not bad seeing that it has the smaller petrol tank (MY93 wrx).

Don't know if it has consumed more petrol since my problem arose, so I can't help you there, car started symptoms at the beginning of August and have only taken it out of the garage 4/5 times since then to charge the batteries up. (Didn't want to take it out more than this incase I damaged something).
The only reason i haven't had it fixed yet, is that I just haven't had time.

So far the following have been banded about as the offending item.
1. Lambda sensor (which I think is the number one suspect)
2. MAF sensor (Don't think it's this as the early ones are generally Ok and pretty robust, could be wrong though, the film type MAF sensors are prone to breaking down, due to oil contamination etc.)
3. Plugs and coil packs - not sure on these, don't think it's plugs as I had these changed less than 1500 miles ago. Could be a coil pack though.
4. Idle position sensor - could be this also.
5. Boost control solenoid - My boost seems fine(during hesitation) and also I have a Dawes fitted so it bypass this, so don't think it's this.
6. Dump Valve - I had a Forge valve fitted, and thus removed it when the problem started, to see if it would cure, put original back on and still the same, so it's not the dump valve.


Muddy.

Elmer Fudpucker

i've just replaced 2 coil packs on my car(my 96)
..... had a slight mis-fire under load.

to check yours,take one off the plug,pull off the rubber'seal'and you will be able to see if they're cracked or not.

redwrx

Ive got an MY93 WRX, and i may be suffering the same problems as you folks ... Exactly what are your symptoms.

My ... 'miss' appears only when i hit full boost around 0.75bar, either under full acceleration,through the gears, or when flooring it in top gear during motorway driving.

ive changed plugs, replaced bost control valve, and replaced MAF , and its still there.....


Frank

naughty

wow! im not alone

thanks for all the suggestions i will put them to good use i will post and findings if i solve the problem
thanks again for the tips

naughty

jonny gav

iTrader: (1)

one good way to test if it is weak coil packs is to close the plug gap up a little, if the problem goes away the coil packs are ready for replacement

muddy

Jonny Gav - Coil packs could be a possibility, hopefully will see when naughty gets it looked at this week.

Redwrx - doesn't sound as if you have the same problem, your on heavy load there, your problem looks like it's happening when on boost. What boost do you get? I would have said look at the boost control solenoid, but it seems like you have already changed this. Why not try a dawes device, and mechanically control the boost, taking the boost control solenoid out of circuit?

Mine, and naughty's car (I could be wrong here) seem to have a hesitation well before any load is applied, probably mainly during low revs, like driving round town. There is an hesitation (Like no response) until the revs are up and above the 2/3k mark. As soon as this is passed the car runs fine, and hits full boost as it should with no problems. It's just it doesn't like low revs.

Naughty am I right or wrong in my interpritation.

Muddy.

muddy

Jonnygav - how's the car? Did you sort your bonnet out?

jonny gav

iTrader: (1)

not yet mate, going to start the hunt tomorrow morning

tinvek

the reason why the miss is worse after the lambda change could be that the old unit was faulty and running the car slightly rich. with the new unit the mixture is leaner and as such needs a stronger spark to ignite it properly hence any poor running being worse.

make sure your plug leads are ok. don't assume that if they are fairly new they are ok. Ford only "guarentee" their HT leads on the zetec for 12,000 miles and i've seen a lot of lead failiures on other cars with coil packs / wasted spark ignition

Dario

Naughty,

Let me know how you get on with the coli packs - my MY01 has a very similar problem.

Regards

Lee

naughty

muddy you seem to have it you are right in assuming its at lover revs but i also seem to have a bit less power when up there this maybe just me though

thanks again everyone and i will suggest the leads and plugs tomorrow ps can u get uprated leads and plugs, if im going to take the jump may as well improve at the same time


naughty

jonny gav

iTrader: (1)

hi mate, the my95wrx's don't have leads, just the later cars do.

your car has a coil pack sitting on top of each plug.

heat from the engine takes its toll on them, thats why they break down.

did you try the plug gap test???

muddy

naughty - come to mention it, I do think at full wack there is something not quite right, but I just put it down to the Dawes Device I have fitted. But like yourself I could just be being paranoid.

Jonny Gav - I haven't looked at the coil packs yet, haven't the time, hence why the car has been in the garage for 2 months not being used. Hopefully change of job in November, will give me more time to get it sorted.

redwrx

Think i may have cured my problems .............MAF sensor.

I went thru the process of cleaning and replacing boost control solenoid, replacing plugs , replacing air filter ...took it to the locla scooby dealer after much head wrecking and they hinted at the MAF.

Coils packs apparently can be checked without removing them, whilst this doesnt replace a visual inspection, another thread on here indicated that the resistance of the pack measured by discoonecting the connector should be around 1.3ohms on each pack.... i tried this and mine where about 1.1. The scooby dealership technician reckoned that coil pack faults tend to exhibit themselves at low rpms... ie <3k

The symptoms i had were..... an apparent missfire under heavy load and full accelaration, but also present when trying to pull away from 70mph in top. I also noticed a hiccup when sat around 2/ 3k and trying to pull away.

Its taken me around 6 weeks of trial and error .... to hit on this.


Dont know if any of the above is useful.

Good luck

Frank


mine is an MY93 'K' wrx ...... no mods

Fuzz

didn't I mention that already.

Andy

naughty

think so

bttt

muddy

naughty - have you progressed any further in finding a cure!

redwrx - I'm pleased you found out what it was, you seem to have slightly different symptoms to both myself and naughty, but I suppose the MAF could be a possibility for our fault.
Looks like I will be checking coil packs and MAF sensor at the weekend then.

Muddy

naughty

cant find any obvious faults i have mentioned all above but they cant see and problems with them

please let me know how you get on


naughty