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2001 SOLD!
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Discussion Starter #1
When i pull away from a light or a stop sign, my car tends to misfire at around 1000-1500 rpm in 1st or 2nd gear MT. It only occurs when the car has warmed up.

From what i can gather, its probably do to a faulty fuel pressure regulator. It seems to be running richer and making me poorer!!!!

The reason is i found my fuel consumption way higher than normal. Also a good friend of mine is a very good mechanic and told me it was probably what was malfunctioning.

We are going to hook up to a laptop and verify for some faults.

I changed the spark plugs. Anyone else have had a similar problem with a 2.5 N/A????

thanks EH!!!!
 

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scarred from battle
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730 Posts
It's probably your knock sensor. The "only when it's warm" would be an indicator.

Could also be plug wires.

I'm having a similar problem with my '98, but I'm 99% certain it's because i've got bad plugs. The coil pack is also suspect, just due ot it's age. (cold/warm doesn't make a difference for me)

could also be that the throttle body could use a cleaning. Apparently there's a valve on the bottom that can get stuck. If you run a search over on RS25.com for misfire, you'll get a lot of stuff.

Front O2 sensor is also sometimes the cause.
 

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Discussion Starter #3
blitzoid said:
It's probably your knock sensor. The "only when it's warm" would be an indicator.

Could also be plug wires.

I'm having a similar problem with my '98, but I'm 99% certain it's because i've got bad plugs. The coil pack is also suspect, just due ot it's age. (cold/warm doesn't make a difference for me)

could also be that the throttle body could use a cleaning. Apparently there's a valve on the bottom that can get stuck. If you run a search over on RS25.com for misfire, you'll get a lot of stuff.

Front O2 sensor is also sometimes the cause.
Yikes, kinda cold here these days to check all that. I guess i got alot of things to check.

thanks for the info.
 
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I am having the exact same problem with my 98 2.0l forester. Has been happening for ages and is now getting much worse, ie bad misfire from 0-3500rpm. It also only happens when hot. I have changed plugs, leads, cleaned and regasketed the idle air control valve, fuel filter and still not fixed. Although when the leads were changed the problem was non existent for a few days but started creeping back.

No codes have been thrown so my theory is that it could be a failing coil pack, otherwise the leads wouldnt have made much difference. Now its getting to the stage where it also happens when cold...

Anyone ever had this problem and fixed it?
 

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Discussion Starter #6
Well my good friend hooked up the Snap-on Solus computer he has and we got no faults. All the paremeters are good. We suspect the wires or the fuel pressure regulator.

Who knows. Like he said, its much easier when you have a fault show up. Its easier to pin-point!!!!:-(

So i guess i'll star changing stuff slowly to find out!!!
 

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2001 SOLD!
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Discussion Starter #7
I changed my spark plug wires on Friday after work. Connector on spark plug #2 was corroded and it stayed stuck on #2 spark plug deep down inside the head... that's right next to the battery. :tempertantrum The tightest part on the bloody engine!!!

Anyways... missfire is gone and the car runs much better and is more repsonsive now. Next up is the Poormans CAI!!!!:biggrin: :spinnasmiley
 

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Asphalt Surfers Unlimited
2004 Forester XT
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huck_this said:
I changed my spark plug wires on Friday after work. Connector on spark plug #2 was corroded and it stayed stuck on #2 spark plug deep down inside the head... that's right next to the battery. :tempertantrum The tightest part on the bloody engine!!!

Anyways... missfire is gone and the car runs much better and is more repsonsive now. Next up is the Poormans CAI!!!!:biggrin: :spinnasmiley
Good work! Glad to hear your Scooby is feeling better. ;)
 
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