Car starts and everything works but idles rough

[JayKillian]

Hello guys I ended up get the new fuel pump and AN line setup for the assembly. The problem I have now is when I start the car all the DL come on and when it turns over the only one that stays on is the CEL the idle is rough on the car I 0ed the SACF 2(probably spelled wrong horrible memory) hooked the laptop up and checked the DTCs cause the CEL(was recommended to check for codes) was on and I’m getting “DTC 0012 Volume air flow circuit malfunction” I cleared and updated and it popped right back up. I’m new too this so I’m wondering if anyone knows what I need to look at I’d be grateful.

Thank you.

 

[gvr4ever]

What fuel pressure regulator are you using?

 

[JayKillian]

What fuel pressure regulator are you using?

 

[gvr4ever]

Do a google search for the error code. Could be the MAF, or connection issue to the ECU. Do you have an idle surge, or more of a stall?

 

[JayKillian]

It don’t stall out till I give it gas but before that it just goes up and down between 500rpm to 1500rpm like it wants to stall out but catches its self

 

[gvr4ever]

I hope this helps. https://www.sixsigmatuning.com/dsm-idle-control

The sad reality is, ODB1 can be a bitch to diagnose. Considering your error code, I'd start with the MAF and boost, vacuum leaks.

 

[Corydolo]

Hello guys I ended up get the new fuel pump and AN line setup for the assembly. The problem I have now is when I start the car all the DL come on and when it turns over the only one that stays on is the CEL the idle is rough on the car I 0ed the SACF 2(probably spelled wrong horrible memory) hooked the laptop up and checked the DTCs cause the CEL(was recommended to check for codes) was on and I’m getting “DTC 0012 Volume air flow circuit malfunction” I cleared and updated and it popped right back up. I’m new too this so I’m wondering if anyone knows what I need to look at I’d be grateful.

Thank you.

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My 03 4g64 had a real rough idle when I got it, I narrowed it down to a dirty MAF and i believe the last person who changed the time belt didn't get the balancer (or w.e. it is) lined out. It idles so much smoother with a clean maf and only idles rough now when it's cold