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Discussion Starter #1
Hi guys I'm having a problem with my s14 sr20det. It idles at 5-600 and idles lumpy. No engine management light. Or strange engine sounds. Car is not down on power what so ever and drives perfect under acceleration of any sort. But when car is sitting at any constant speed below 120k ish it is hesitant and jerks a bit. Give it a little more gas and accelerates smoothly. Any help would be greatly appreciated. Thanks
 

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Several things to check/replace:
- Spark plugs. Use only NGK OEM plugs.
- Dirty or leaking fuel injectors. Run some good injection cleaner, like Techron or Redline SL-1, through the system; give the cleaner about a week or two to do it's job.
- Vacuum leak. To check the intake system for a vacuum leak, attach a vacuum gauge to a full vacuum source. A good place to connect to is the charcoal canister. There should be three hoses connecting the carbon canister. Two of the hoses go to a purge valve that's built into the canister. The second larger hose off the purge valve should be your vacuum line. With the engine fully warmed up, the reading at idle should be 18 - 20 InHg. At 3,000 RPM, it should be around 21 InHg. If readings are under 18 InHg, check the intake manifold nuts to make sure they are tight. The gasket may have failed; spray a water mist at the gasket to see if the gauge reading changes. Also check the intake plenum bellows at the throttle valve and at the MAF for cracks or loose clamps.
- Leaking blow-off valve. Make sure all the clamps are tight.
- Leaking EGR valve.
 

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Discussion Starter #3
Ok I'm going to chan he spark plugs and clean injectors this weekend and see. I'm quite new to turbo cars but if I had a vacume Leak would this not effect power/boost.. Thanks
 

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Sup Mod keeping the peace
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A vacuum leak would create a leaner mixture which might affect the idle. It's worthwhile checking it if changing plugs and cleaning injector doesn't fix the problem.
 

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Discussion Starter #5
Oh that may be the culprit because it does seem to run lean as if I hold a rev of let's say 3,000k it will make small backfires but not drop revs
 
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