MAF sensor code, o2 sensor code, high idle, poor drivability

[kidwiththelaser]

Ive been working on this car since the summer, just to have something to do. Its almost done!

The current symptoms are:

-High Idle about 1000-1050 rpms (very steady once its warmed up)

-Poor drivability. It accelerates speradicaly, its hard to describe. Not a steady acceleration.

-2 CELs, one for 02 sensor and one for Maf sensor.

The o2 sensor code makes sence, because it was spitting alot of coolant and oil into the exhaust due to a bad turbo. Ive fixed that problem, it now has a 14b with absolutly zero shaft play.


Im going out of town until tuesday, so I wont be able to reply until then. But the first thing im going to check is for boost leaks. If that doesnt do it, any other ideas?

Thanks alot for all your help, I appreciate it!

-Charlie

 

[andymoraitis]

Charlie,

You already have your answer. Replace the MAF with a known working unit. You didn't specify which O2 sensor was tripping a code but if it's the front and replace it with an OEM Denso from:

http://www.sparkplugs.com

If it's the rear O2 from running without a cat ignore it and don't worry about it. The MAF issue will certainly create the issues you're describing however so that definitely needs to be changed.

Please follow up and let us know your results,

Andy

 

[kidwiththelaser]

Thank you very much andymoraitis!!

I went and unplugged the mas, and drove it around the block a few times, and it deffinitly pulled alot harder. BUt it still idled funny. So Ill have to look into that more after I get a new mas.

thanks alot!

 

[kidwiththelaser]

okay, I bought another MAF, and it still is sending the code.

So I cleared the code, and hooked up the Snap On code scanner thingie.

And it says at idle:

RPM: 1004-1032
MAF: 0.00 g/s
spark advance: 1.5 degrees.
02 sensor = .18V

Then I held it at 3800 rpms and it read as follows:

MAF: 0.00 g/s
Sparl Advance: 6.5 degrees


So for whatever reason the new maf isnt sending any information to the computer either.
I quick checked the wires to the maf connector, and they all seemed fine, and hadnt been tampered with.

But then I looked at the wires going to the ECU, and the have definetly been messed with before. So im going to look at the wiring diagrams, and see what wires to look for.

 

[kidwiththelaser]

okay, well I found a wire for the MAF that wasnt cut!!

So I soldered it up, and now at idle trhe snap on thingie reads:

RPM: 1350
MAF: 5.7 g/s
Spark advance: 18.5 degrees

So thats a pretty drastic change in spark, and now its idling steady, but waay too high.

Any ideas as to what to do?

 

[kidwiththelaser]

Also, If I force it to go idle lower, ie hold the brakes, put it in gear, and slowly release the clutch, it will still run perfectly fine.

 

[andymoraitis]

Charlie,

Good job in tracking down and figuring out your problem. Here's a brief guide on setting idle with the BISS screw:

http://www.vfaq.com/mods/BISS-2G.html

Let me know how it works out, k?

 

[kidwiththelaser]

Charlie,

Good job in tracking down and figuring out your problem. Here's a brief guide on setting idle with the BISS screw:

http://www.vfaq.com/mods/BISS-2G.html

Let me know how it works out, k?

So I need to use the scan tool for it. Im not sure if the scan tool at work can hold the IAC motor like it says in the VFAQ. I guess ill figure it out on Tues when I work next.

Ill update then!

thanks alot andymoraitis!

 

[kidwiththelaser]

Okay, sorry Ive taken so long to reply.

But Im pretty sure I got it all figure out, I adjusted the idle and its nice and steady. But it still had the O2 sensor code, and a Manifold differential pressure code.

So I tried to order a new 02 sensor, but nobody had one I could order get today, so I decided to check over the wiring.

I found a wire that was loosely connected, and it was not inside the water proof connector. So I put the wire in properly, and connected the 02 sensor harness.
Then I cleared the codes, and started it up and turned it off a few times. And even after driving it home, the codes didnt reappear.

So now all I have to do is the rear brakes, and put the interior back together, and ill be good to go!

thanks alot for all the help!