Hesitation, juddering etc..

[dapat]

Hey guys,

Had my 2001 GG9 wagon for a few months now and has always had a problem with cold starts.
On warm days its not so bad but cold or wet days its an issue.

 

When starting from cold it starts and idles fine. But when you then go to drive while engine is still cold it hesitates (loses almost all power/drive) from 1500-2500 rpm... Once it's warm the issue seems to clear itself up. Had a look on the internet and this seems to be a common issue. But they all seem to have poor idling and suggest a huge list of things it could be.

Is there an easy way to find out before I go looking at everything? Seems temperature reliant so maybe coolant sensor? Or throttle sensor?

 

Any help would be appreciated.

Thanks.

[Guest]

All of my phase 2 subarus have had the same issue. V5 wrx, 2000 foz, 2001 rev d legy. Along with every other post 1998 sub Ive driven.

[Andy_Mac]

Same on my old rev C. Tried o2 and AFM with no improvement

[calebwrx]

Sounds exactly like my V7. It's always annoyed me but apparently it happens to a lot of our cars. Although come to think of it I've never felt it in my friends V8. @IZichard you have this with yours?

[dapat]

Yeah, I had the AFM out and the spark plugs, fuel filter, TPS, plugs, all looked good and cleaned. Put injector cleaner additive in the fuel. Might well be the gearbox. But that was supposedly serviced recently before I bought it.

[Guest]

17 minutes ago, dapat said:

Yeah, I had the AFM out and the spark plugs, fuel filter, TPS, plugs, all looked good and cleaned. Put injector cleaner additive in the fuel. Might well be the gearbox. But that was supposedly serviced recently before I bought it.

 

Tbh Id just learn to live with it. Theres a few threads on here regarding the same issue. Would think it has something to do with the warm up enrichment/fuel trims side of things. 

[IZichard]

6 hours ago, calebwrx said:

Sounds exactly like my V7. It's always annoyed me but apparently it happens to a lot of our cars. Although come to think of it I've never felt it in my friends V8. @IZichard you have this with yours?

Can't say I've ever noticed it, though I'm pretty diligent about warming up my car for a few minutes before I drive it. I've driven it cold before and never had an issue. My clutch is a little shuddery for the first 2-3 engagements but the engine is smooth as always.

[Subru]

Is it worse on wet days opposed to just cold days? Could moisture be an issue somewhere?

I have had issues with other another car when cold started on a wet day it runs really bad but this was water in the distrubuter cap and the HT leads were not in best shape too.

[dapat]

On 2/5/2017 at 7:00 AM, Subru said:

Is it worse on wet days opposed to just cold days? Could moisture be an issue somewhere?

I have had issues with other another car when cold started on a wet day it runs really bad but this was water in the distrubuter cap and the HT leads were not in best shape too.

 

I'm not sure if its worse on a wet day. Next time its wet I'll try and remember to check.

[Prodrivebugeye]

Have you had a look at the idle control valve? Had similar issues with my old rev c etune and after cleaning that it seemed to run a bit nicer on cold start than it used to. 

[slystiguy]

It's normal-ish for a bit of hesitation on any cold engine but it shouldn't be terrible/undrivable. Next time it rains check your airfilter to see if it's wet?