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lumpy when cold, perfect when warm
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Old 09 Mar 2013, 08:02 AM   #1 (permalink)
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Unhappy lumpy when cold, perfect when warm

Got a completely standard UK MY99 Turbo 2000, which runs very lumpy on a cold start, revs fluctuate between 1300-1500. Revs gradually drop as engine warms up like it should. The engine fires up first time every time, recently had fuel filter replaced and fuel leak repaired so not sure if its related and its caused a airlock. Once the engine is at optimum temperature it runs smoothly. There is no check engine light on.

Is there an easy way to test fuel pressure?

Spark plugs were changed May 2012 (NGK PFR6B)
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Last edited by alunian; 09 Mar 2013 at 08:04 AM. Reason: adding details
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Old 09 Mar 2013, 08:34 AM   #2 (permalink)
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Re: lumpy when cold, perfect when warm

Cts would my first stop
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Old 09 Mar 2013, 08:41 AM   #3 (permalink)
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Re: lumpy when cold, perfect when warm

Quote:
Originally Posted by bugeye_bob View Post
Cts would my first stop
what does cts stand for?
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Old 09 Mar 2013, 09:03 AM   #4 (permalink)
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Re: lumpy when cold, perfect when warm

Coolant Temp sensor
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Old 09 Mar 2013, 12:35 PM   #5 (permalink)
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Re: lumpy when cold, perfect when warm

are you referring to the ECU one with the 3 wires/connections?
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Old 10 Mar 2013, 12:03 AM   #6 (permalink)
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Re: lumpy when cold, perfect when warm

agree with Bob,CTS is located iro the alternator...triangular plug design..
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Old 10 Mar 2013, 12:58 PM   #7 (permalink)
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Re: lumpy when cold, perfect when warm

OK. before I go messing around just to remind you, the problem started when I had fuel leak, every cold start fires up first time, when pulling away with enough throttle it runs jerky, off throttle is fine. When engine is warmed up and applying throttle it runs ok.

I can see where you two are coming from because I mentioned temperatures.
However since I've had a fuel pipe taking out and replaced surely that would have created a airlock, the pipe that was replaced was the one that its in line with the rear seat.
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Old 10 Mar 2013, 03:03 PM   #8 (permalink)
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Re: lumpy when cold, perfect when warm

Had a look around the engine bay, cant see a triangular plug anywhere near the alternator. All I can see is a wire clipped on top of alternator and to the side of it. Just below and to the left of the alternator is a sensor with only 1 very thin wire coming from it.

Tried looking behind the manifold cant see it there either.
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Old 17 Mar 2013, 06:26 PM   #9 (permalink)
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Re: lumpy when cold, perfect when warm

Is this the correct part, both are from the same seller, one is ebay store the other is the official website, info in description holds the same part number 22630AA161?

Impreza Turbo UK & WRX ECU Water Temperature Sensor | eBay

Subaru Impreza Turbo ECU Coolant Temperature Switch 98 on

Got a feeling I need to remove the alternator to see/get to it.

Thanks in advance
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Old 18 Mar 2013, 01:14 PM   #10 (permalink)
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Re: lumpy when cold, perfect when warm

can anyone confirm if the above links are the correct coolant temp sensor and if they know some where cheaper.
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Old 18 Mar 2013, 02:19 PM   #11 (permalink)
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Re: lumpy when cold, perfect when warm

there are 2 listed for 98`s, you need to LOOK which yours is.

Subaru Impreza Turbo ECU Coolant Temperature Switch 98 on
Subaru Impreza Turbo ECU Water Coolant Sensor 92 to 98
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Old 18 Mar 2013, 06:20 PM   #12 (permalink)
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Re: lumpy when cold, perfect when warm

Quote:
Originally Posted by bugeye_bob View Post
Cheers, I'll take a look when there is some decent weather. However I have a MY99 (registered end of September) so it will most like be the 3 wire (triangular) sensor.
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Old 31 Mar 2013, 10:42 AM   #13 (permalink)
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Re: lumpy when cold, perfect when warm

any tips for removing alternator, I tried to take remove it yesterday, took the hinge bolt out and removed the adjustment bolts and it wont lift out, im I missing something?
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Old 31 Mar 2013, 01:22 PM   #14 (permalink)
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Re: lumpy when cold, perfect when warm

it will just be tight id say, its even more fun re installing lol,
try a screwdriver between the alternator and where the AC pump would be (if fitted).
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Old 31 Mar 2013, 03:39 PM   #15 (permalink)
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Re: lumpy when cold, perfect when warm

They get tight on the long bolt side, spray a little wd on the lugs and wriggle it down abit then it pulls out easy mate. Ive got the same problem with mine and changed the ecu cts ( and all sorts of other bits) but it still runs shite from cold so im taking it al jeffries tuesday. 60 quid to diagnose it apparantly. Cant wait to get it done, been doing my head in for ages!
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