Can someone tell me if there's anything wrong by looking at this graph? Is the o2 sensor reading normal? Log attached too. I have an idle problem. When let off the gas the RPMs drop to 300-400 and car stalls occasionally.Thx



These are the modded ISCV graphs. They didn't resolve the issue.

 

desired idle 78? fix this.
what dv are you using?

 

Do you have cams? Bigger injectors? What are fuel trims? When did this start happening?

 

An exact mod list might help to pinpoint the issue. Also, like mplspilot stated, fix that low spot in your desired idle rpm table.

 

Im using stock DV. All my mods are in my sig.
Regarding that low cell in desired idle- Ive read in a few threads that it doesnt affect anything, but i will change it.

 

have u reset your base idle screw?

 

I didnt touch the Idle screw. Was I supposed to reset it?
Heres fuel trim graph. Its under 6%

 

do the BISS adjust proceedure.

cant hurt

 

Did it just randomly start to have the idle issues? Intake pipes can and will make a difference in your idle.

 

If dvv is stock, my guess would be a vacuum leak maybe..

 

I think I found the problem guys. First - I cleaned my MAF. But most important - while I was cleaning my engine bay Ive touched the groung wire that goes from the intake mani to the firewall and it felt a little loose. I pulled on it and that thing was completely torn off the back of the manifold. Ive made a new 8gauge wire and test drove the car. RPM dont drop that low anymore. Once in a while to like 600 or so but nothing like before. Engine a lot smoother on low rpms.
So, one of those things fixed it.
On the other hand, immediatly after the fix the car doesnt start right away. Takes about 6 or 7 cranks(engine turns) before it catches. Not sure why now.
Can it be because it was tuned with bad ground wire?
Thx

 

did you check your base idle?

takes 2 seconds with evoscan...

start car (warm...)
click "sas mode" or "speed adj screw mode"

if idle drops below 700 then adjust the screw until its normal...

 

I've just checked base idle today. I started evoscan(warm car), clicked sas mode(check engine light came on then off after i stopped sas mode) - the idle didnt drop at all, stayed where it was.

 

I'm going to look into this! Recently after a clutch job my car's idle is HORRIBLE. To the point I don't even want to drive it. I wonder in their sloppy work if they tore off one of the ground wires?? I also re-located my batt to the trunk. It's only using a single ground wire to the chassis. I'm going to run another grnd wire up to the stock grnd terminal and see what happens.
Thanks for updating your thread! It may save me some time!

 

Well....fixing the ground wire helped a bit. For about a day idle was a lot better. I drove to Lake Tahoe on the new years ( snow and temp in 20s), there was a lot of traffic on the way and the car started to do the same thing, almost stalling every time I press the clutch - rpm drop to 300-400 and oil dash light is blinking - Ive noticed my afr go to above 20 during these rpm drops. I dont know what to do really. Cant get another MAF to test anywhere. Dont know how to determine if its my front o2 sensor. Will see how it will behave back here in warmer temps.

p.s.Also check engine light came on again after a cold start. Car really struggles to build up rpm when starting.