2G really bad idle drop

[Jasonballer]

hey guys I'm having this terrible issue and i can't seem to nail it out the problem. ok so I'm gunna start off by saying my problem is that my car is idling really really rough like rough i mean the car will sometimes start off ok and then all of a sudden the rpms will drop suddenly to roughly about 800rpms or even sometimes 2-300rpms. the car would rarely die but it just sounds terrible and it sounds like it wants to shut off which it does sometimes.

I've replaced the spark plugs and wires and put in a new iac sensor. The other thing i figured out, which I'm assuming, it could possibly be is the maf wiring. Only because when i tap the harness connector that is connected to the maf it seems to change the idle suddenly.

Any help would be great and appreciated thanks guys ill respond as quick as possible i need help asap i have long rides to work and i want this thing fixed hopefully by the weekend

Another thing i wanna throw in as well is that when i peek over at the boost gauge, I've realized when the car is idling fine the pointer is at roughly 12-13 like it normally should be but as it idles bad it will drop to about 7 to about 4/5. And at times, the rpms rev randomly and it will go up higher then the normal rate. Usually when i take off its hard the car will jerk and boost won't kick in until afterwards with a sudden burst.

thanks guys

 

[92AWDHX40]

Have you done a boost leak test if not I would start there.

 

[Jasonballer]

yup I've done that about a few weeks ago but got no results from it such a bugger this problem been trying everything

Have you done a boost leak test if not I would start there.

 

[PlanZero]

Is your bov recirculated? The fact that the maf wires are loose pretty much answers your question.

 

[Jasonballer]

Is your bov recirculated? The fact that the maf wires are loose pretty much answers your question.

what do you mean by having it recirculated ? any idea how i can fix the maf wiring?

 

[crash]

Bov recirculated means that the large hose coming off your bov goes back into your intake....stock condition. If you vent to atmosphere, i.e. no hose, the car will run rough and may stall on decel.

I'll agree with planzero on this one. If you wiggle or tap a wiring harness, wire, sensor, etc and it changes your condition, most cases that item is the issue. In this case your harness / connection to your mas.

Also, I haven't read your profile so I don't know if you're running an aftermarket boost gauge. But if you're worried about what the stock boost gauge reads, don't be. It's just for looks.

 

[steve]

But if you're worried about what the stock boost gauge reads, don't be. It's just for looks.

Except that the stock boost gauge is driven in part from the airflow readings so indirectly you seeing an indication of what the ECU thinks the airflow is.

 

[HeadsUp Panda]

Have you disconnected the maf connector and inspected it or the wires coming from it? Any results from messing with a single wire? Or just the connector? If your problem can be affected by wiggling it I would say it's coming from this area. I'd be pulling the connector and inspecting the teeth and wires.

 

[Jasonballer]

Bov recirculated means that the large hose coming off your bov goes back into your intake....stock condition. If you vent to atmosphere, i.e. no hose, the car will run rough and may stall on decel.

I'll agree with planzero on this one. If you wiggle or tap a wiring harness, wire, sensor, etc and it changes your condition, most cases that item is the issue. In this case your harness / connection to your mas.

Also, I haven't read your profile so I don't know if you're running an aftermarket boost gauge. But if you're worried about what the stock boost gauge reads, don't be. It's just for looks.

yup i also have an aftermarket boost gauge which reads about 12 on idle and 5 to about 7 sometimes when its poor and the rpms drop to about 2-300 which sucks

 

[Jasonballer]

Have you disconnected the maf connector and inspected it or the wires coming from it? Any results from messing with a single wire? Or just the connector? If your problem can be affected by wiggling it I would say it's coming from this area. I'd be pulling the connector and inspecting the teeth and wires.

i have taken it off but its hard to inspect I've looked at it and it seems to look fine other then when i tap it while its plugged in it goes retarded. I've tried almost everything i have a muti metre also just don't know how to use it i herd its possible to use it for the maf

 

[10's or bust]

If you wiggle it and it changes Then it means there's a break in a wire in the connector.

Do a continuity test to figure out which one is broken with The multimeter

 

[HeadsUp Panda]

If you wiggle it and it changes Then it means there's a break in a wire in the connector.

This is exactly what I was getting at. Just didn't know how to put it into words at 5am this morning .

 

[Jasonballer]

Do a continuity test to figure out which one is broken with The multimeter

how exactly can i do that i have no idea how to pull that off should i unwrap the harness as well ?

 

[10's or bust]

All you have to do is take each terminal on the connector and check these each terminal individually with the multimeter. And back probe the wire back to where it goes into the to the car's computer ECU. Check out Vfaq.com for the proper wiring schematic and carefully test each wire. Takes a little time but is well worth the effort.

 

[1000hpgsx]

This may help you. There is a wiring diagram for the 2G MAF half way down.
http://vfaq.com/index-main.html
click on intake
click the link beside "2G MAF in a 1G TEL/GVR4"

 

[Diamond Star Werks]

If you wiggle the connector and idle changes then start there. make sure the connector fully seats and clip locks onto the MAF, check the harness connector and make sure the terminals are all securely seated in the connector and are not corroded and/or damaged/bent. View and repair as needed then check continuity between MAF harness connector and ecu connector. Here is a ecu pinout http://www.dsmtuners.com/threads/2g-turbo-ecu-pinout-w-wire-colors.281763/
If all checks well idle still messes up when wiggling MAF connector, I'd suggested a recheck of the harness connector and MAF pins, then replace MAF.

 

[Diamond Star Werks]

Before replacing any parts you should do all basic checks ruling out air and fuel since it runs. Check fuel pressure if possible, check compression, make sure tps/biss screw/throttle stop/set screw are all properly set, make sure of no vacuum leaks and check fuel trims if possible to so if your running to rich or lean. Scan ecu for any trouble codes that may assist in diag. Make sure pcv valve isn't stuck or brake booster isn't leaking air.

 

[Pcraker1]

another thing i wanna throw in swell is that what i peek over at the boost gage I've realized when the car is idling fine the pointer is at roughly 12-13 like it normally should be. but as it idles bad it will drop to about 7 to about 4/5 . and at times the rpms rev randomly and it will go up higher then the normal rate. usually when i take off its hard the car will jerk and boost won't kick in until afterwards with a sudden burst thanks guys

Did you ever figure this problem out

 

[pauleyman]

Did you ever figure this problem out

The OP hasn't been seen in 7 years. I would suggest making a new post with your specific problem and information.

Please use this as a guide.

https://www.dsmtuners.com/threads/diagnosis-101-ask-good-questions-to-get-good-answers.540259/

 

[steve]

Did you ever figure this problem out

Did you read the thread to see what you might be checking while you wait?