hiya peeps got a prob with my 1999 STI V5, its seems to cut out when I slow down, this seems to happen after about 10 mins of starting the car, when the car is hot i.e. idling or town driving its ok, but when on a run at a constant speed 40mph+ when I slow down to stop it cuts out.. Any ideas???

I notice that that when I do stop if it hasn't cut out it idles very very low, once reved it revs as normal...

its getting very frustrating, any help appreciated..

 

99's have very delicate MAF's that are easily damaged. They can cause all sorts of problems including the ones mentioned.

Do a search for ways to check it and take it from there.

 

Check for ECU faults http://www.saxonfields.freeserve.co....iag%20Page.htm

As mentioned the most common reason on MY99/00 is the MAF but it could also be the Lambda(O2) sensor

 

Hmm - sounds just like my Link ECU!! on my sti5 1999 - Is your car standard?

 

the only mods are a decat centre and back box...

judging by the search it looks like its either the MAF or the lambda sensor...

any way of eliminating either... or are there any garages in west london who could tell me what the ECU codes would be, I assume that would be the most accurate way of finding out ????

 

23 MAF

32 Lambda

 

I would change both maf and lambda sensors

 

That's quite a serious problem on a standard mapped STi5. Get the MAF changed very quickly and keep it off boost. A lean MAF combined with not being run on 100 RON will see some internal damage pretty quick. May be the lambda also.

Use the link above to check for faults. Damaged MAF's generally dont give a code, but a lambda normally will.

Best place to go if you're west London is Power Enginnering. The will tell you within about 10 mins

Is your speedo reading ok out of interest?

MB

 

DBM, thanks for your reply, much appreciated, as regards the speedo reading, it is erratic, and tends to fluctuate...

i'll go down to PE tomorrow, I do have knock link and that has remained on the 1st light and not changed since the fault developed...

 

Ah ha, it could well be that your speedo convertor has come loose. This will cause an erratic idle... Mention this to them when you go. You may then be able to ignore my MAF comments above with regard to this problem

MB

 

DBM, where is the speedo converter located??

 

sounds like a MAF< had exactly the same symptoms on my Type R, drive off-boost until sorted

 

Agreed Tony, but Ive seen a loose speedo convertor do this too.

Skool, its down behind the IC on the drivers side from memory. Its an inline one, so if you trace the speedo cable through the bulk head, you will find it. Its normally a small black plastic box.

MB

 

STi 5 have electronic speedos/sensors.
The convertor is usually behind the dash/stereo (or somewhere) and is an electronic unit.

Skool,if you are saying that the revs are fluctuating then I think its MAF related.
If the MAF hasnt been changed recently then just get a new one for the sake of it,theyre £77 from the main dealer or £100 from PE (IIRC).

Have you not tried the CEL test yet? ie connet the connectors under the stearing column to check for fault codes?

 

Skool, did you mean the revs fluctuate, the speedo, or both?

MB