Pick your brains - HELP with surge issue - Perth-WRX.com

DEDLYWEPN · #1 22-06-2007, 07:51 PM

Hey guys,

I'm having an issue with my car, which i've only noticed in the wet. It surges like its run out of fuel or the fuel pump has failed when you give it a boot around a bend or even on a straight. But only seems to happen when its wet.

I thought it might've been low fuel, so I just filled up (like 20 mins ago) and went up the road from the servo, floored it and it backed off and started spluttering and carrying on, slowing down and wouldnt accelerate or build up power until I took my foot off.

Did it every time I gave it a bit of throttle, then heading home I put it in neutral (doing bout 50kph) and floored it. Wouldnt rev past about 3500rpm and sounded like it was anti-lagging!! Spluttering etc... then al of a sudden (after about 15 seconds) went to full throttle, redline...

Any ideas??? Anyone experienced this before?? It's an auto, MY99, if that makes a difference

tuna · #2 22-06-2007, 08:10 PM

air flow meter, or 02 sensor.

Mister Two · #3 22-06-2007, 08:30 PM

my99.... AFM. Its a common problem. I think its around $150 for a replacement.

Im still surprised Subaru still hasnt done a recall for this and provided a permanent fix for this. Almost every my99/00 owner Ive ever met has come up against this issue at least once.

tuna · #4 22-06-2007, 08:40 PM

Quote:

Originally Posted by Mister Two

my99.... AFM. Its a common problem. I think its around $150 for a replacement.

Im still surprised Subaru still hasnt done a recall for this and provided a permanent fix for this. Almost every my99/00 owner Ive ever met has come up against this issue at least once.

for a car thats 7-8 years old, a 3 years/100,000 warranty isnt going to help a hell of a lot

DEDLYWEPN · #5 22-06-2007, 08:31 PM

Replaced afm only two months ago, was running a unifilter pod - but not anymore, so would it be more likely o2?? And if subaru put their analyser on it, will that pick up a code for the O2 sensor??

Thirdly, why would it only be doing it in colder/wet weather??

JB

IMPRESHER · #6 22-06-2007, 08:33 PM

Would say as above mentioned AFM..
Is there any water leak in to the air filter if your running one , that would coz things to run ruff.

DEDLYWEPN · #7 22-06-2007, 08:38 PM

As mentioned, running STANDARD airbox, so water leaking in would be unlikely, I do have an RMS CAI though, so maybe water's coming up through there.... Never had this issue last winter though

Mister Two · #8 22-06-2007, 08:55 PM

yeah I know they are way past the warranty but even then its an inherent design problem. Even if it was past warranty, they should still do a recall.

Back in 1996 Subaru did a recall on all RS Libertys long past the warranty for a full head, piston replacement along with a few other parts all because of the tappet noise. Now the tappet noise can be made to go away with a flush and thinner oil so it wasnt causing any permanent damage but Subaru still did the recall anyway.

A malfunctioning AFM on the other can cause major damage to an engine in the form of a lean out. So for a fairly cheap part, youd think Subaru would simply bite the bullet and just order a recall.

Quote:

Originally Posted by MY REXTC

Replaced afm only two months ago, was running a unifilter pod - but not anymore, so would it be more likely o2?? And if subaru put their analyser on it, will that pick up a code for the O2 sensor??

Thirdly, why would it only be doing it in colder/wet weather??

JB

Isnt the Unifilter pod an oiled foam type pod? Oiled filters and Subaru AFMs generally dont mix. Even if you did replace it two months ago. Did you change the filter type or go back to stock? Otherwise the AFM would have just died again and you're back to square one.

As for problems only in the cold. Colder air is more dense and this I imagine would just exacerbate the symptoms of a dead or dying AFM.