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Thanks for a very informative board here. Already using it in issues on the 2003 I6 4spd auto I just picked up at auction as basic trans.

Will also be posting to the 1st Gen board...
I'm getting p0340, and I get surging idle on start up only when systems are cold ( outside temps 50s-70s more or less). I occasionally get maf codes on cold start, that go away and don't recurr on warm start. Maf sensor LOOKS newish, I replaced camshaft position sensor. Once warmish (like 2 minutes of running) idle settles in to the 700 rpm. When warm operating, the tach also DROPS to 0 on decel, immediately bouncing back. Doesn't reflect what the engine is actually doing.

I'm not really convinced there's a real timing problem causing the 0340 code, it just runs too good other than cold start.

Someone mentioned low coolant can cause startup idle surge, I plan to check/replace vacuum hoses in order of convenience. Is the sensor in the middle of the big air tube (between air box and throttle body, on firewall side) the IAT? Would a fault in that be contributing? The tube from it is the first one I'll replace, it looks like shit. What else should I be doing? Can someone point me to a good timing check video? Can that be done without too much tearing apart?

Thanks for your thoughts!

I'm pretty convinced once I get that code gone, I'll have an inspectable car (hopefully for net under $700! Pretty freaking awesome).
 

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Thanks for a very informative board here. Already using it in issues on the 2003 I6 4spd auto I just picked up at auction as basic trans.

Will also be posting to the 1st Gen board...
I'm getting p0340, and I get surging idle on start up only when systems are cold ( outside temps 50s-70s more or less). I occasionally get maf codes on cold start, that go away and don't recurr on warm start. Maf sensor LOOKS newish, I replaced camshaft position sensor. Once warmish (like 2 minutes of running) idle settles in to the 700 rpm. When warm operating, the tach also DROPS to 0 on decel, immediately bouncing back. Doesn't reflect what the engine is actually doing.

I'm not really convinced there's a real timing problem causing the 0340 code, it just runs too good other than cold start.

Someone mentioned low coolant can cause startup idle surge, I plan to check/replace vacuum hoses in order of convenience. Is the sensor in the middle of the big air tube (between air box and throttle body, on firewall side) the IAT? Would a fault in that be contributing? The tube from it is the first one I'll replace, it looks like shit. What else should I be doing? Can someone point me to a good timing check video? Can that be done without too much tearing apart?

Thanks for your thoughts!

I'm pretty convinced once I get that code gone, I'll have an inspectable car (hopefully for net under $700! Pretty freaking awesome).
Hello there. It could be a few things to be sure. Its is possible that you have an electrical short somewhere in the wiring harness. Not sure which sensor you are referring to but the IAT (Intake Air Temperature sensor) is inside the hollow tube of the MAF. They are replaced together.
I am attaching the pages for you out if the factory service manual (FSM), hopefully it helps.

It is normal for the car to rev. higher than idle when cold started.
 

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Discussion Starter #4
Awesome, thanks so much for the response. The surging at startup is just a higher level of RPM, it's pulsing up and down, up to about 1300(?) then down to almost stall, repeatedly for about a minute or 2. What is the sensor visible outside the middle of the intake tube? Maybe I'm seeing the outside part of what you describe as inside?

And, just totally pooched headliner reattachment... Any suggestions for cheap fixes? Upholstery guy said 200
 
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