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Shitty idle, and longer start?

JH32

By JH32,
in Engines & Forced Induction

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JH32 Grand Master

JH32

Posted
Posted

Does anyone else's RB20 idle funny?

Mine will sit at around 600rpm, and then "hunt" up and down between 600 and around 800rpm.

It's really annoying coz it feels like something's wrong.

This has happened since I got it, before any mods (ie. bov, bleed valve, fuel pump).

How can I fix this??

ALSO ...

now that I've fitted the bigger fuel pump, it seems like it's harder to start the car?

It takes longer for the car to start when you have the key turned?

What could this be?

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https://www.sau.com.au/forums/topic/6125-shitty-idle-and-longer-start/
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TTT Grand Master

TTT

Posted
Posted

jimih.. all of the above are good points..

I'll add one more..

Also try reseting your ecu.

since you've got all these new mods, you should reset the ECU and then go for a thrash so that it learns things from scratch..

there is a thread on how to do this but here are quick instructions..

**disconnect battery.

**Step on brake pedal until all power is drained and the brake lights no longer come on.

**Plug battery back in.

**Start car, thrash it around for a few minutes around the streets.

**Done.

blind_elk Grand Master

blind_elk

Posted
Posted

"Hunting" could be the early signs of the AAC valve starting to play up. Just needs a clean.

The "start" problem - I was reading last night that too-cold a plug can cause cold-start problems.

blind_elk Grand Master

blind_elk

Posted
Posted

AAC = Auxilliary Air Control (don't people read posts around here? I've lost count of the number of times I've had to explain that). Its at the back of the plenum chamber. Disconnect the orange plug to see if the idle stabilises.

You need to run a lower heat range number. I run a heat range 6. I think you may need to go to a heat range 5. Go to www.ngk.com.au - it has a FAQ about plugs and there is a question specifically about the heat range.

Hicks Mentor

Hicks

Posted
Posted

Do you have some sort of computer ie. S-AFC?

Theres an option you can turn up and down, forgot what its called but its for atmospher bov's(stops the car kinda stalling when the boost is released) when this is on cold start is shit!

I turned it off on my car and haven't had any problems since.

But like others said, it could be your air flow metre.

Hicks Mentor

Hicks

Posted
Posted
Originally posted by GTST

jimih.. all of the above are good points..

I'll add one more..

Also try reseting your ecu.

since you've got all these new mods, you should reset the ECU and then go for a thrash so that it learns things from scratch..

there is a thread on how to do this but here are quick instructions..

**disconnect battery.

**Step on brake pedal until all power is drained and the brake lights no longer come on.

**Plug battery back in.

**Start car, thrash it around for a few minutes around the streets.

**Done.

I read that on another site, didn't know if it was true or not. Didn't have the balls to try, thought it might **** up all my settings.

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