SR Idle Problem

[ItzGenX]

Ok, these problems have to stop. My car will not idle at all by itself. Without the MAFS plugged in, it will kind of surge idle (very high) and eventually die. With the MAFS plugged in, it will not idle at all, I can start it up with my foot on the gas and rev all day long. I've tried the idle screw etc (its all the way out now). Any ideas on what my problem is? The idle thing is plugged in.

[Movingviolation240]

could be a big vacume leak, is the IAA plumed back into the intake pipe after the turbo? It sounds to me like a vacume thing, I'd check all your lines and see how they look. Try adjusting the IAA back in a little. If that dosn't work maybe you can start playing with your 'adjustable' sensors (timing, TPS, ect) and see if you can tune it out a little.

Smart money is vacume related though. If it were somthing mechanical it would stumble and backfire more I'd think.

PaulOrlando, FL

[ItzGenX]

I've gone over vacuum a billion times (well not that many but eventually). How would I adjust TPS? I know the CAS, have always been playing with it since the car started. The throttle plate, I been trying to adjust it out a little but didn't do much. Idle air is plumbed into that hole on the intercooler cold pipe.

[quiksilvia]

what about a dirty mafs?

[SpeedRacer1]

The TPS shouldnt be causing these problems. Is the MAFS grounded properly?

[MojoMan]

There are to many things that could be wrong. You need to go over everything one by one. Its proly not your tps. It could be your maf. barrow someones to see. You have gone over your vacuum to check but do you know if its even correct? There are only a few things that would cause this. Vacuum is a big reason for bad idle. Its proly not timing, plugs, or fuel related. But that depends on the exact idle. Im not there to hear and see it. Test your maf.

[ItzGenX]

Maf has been tested and works. Before I installed it, I cleaned it out pretty good where the filaments were black, and I turned them shiny. Ground is good I think, how else would I get 12.6 volts using it with the multimeter? I'll check over a bunch of things today. This problem isn't too much to explain. If you wanted to see or hear it, put it this way. The ignition is set pretty good right now and it sounds smooth. It is just when you start it, it will start like normal and right when it holds a high idle (1200RPM) it will go straight back down to zero. No crackles or pops. I will go check over a few things again today and see.

[ride4lame]

Mine does something similiar...it runs good...idles at about where it should...But when i let off the gas, it drops down to about 500rpms and almost stall...any ideas?

[ItzGenX]

I haven't found my problem yet. I am going to take all my vac lines and intercooler pipes etc off on tuesday when I'm off. Then test them or blow in them while holding other side. Then put everything back on. My car actually does not want to idle at all right now. With mafs plugged in, starting it will raise its rpm to 1k instantly, then it falls to about 100rpm and stumbles between there and 300rpm a couple times, then dies. I've tried adjusting idle screw and such, doesn't make much of a difference. My car can idle all day long with the mafs unplugged, but idles at 2500. Adjusting idle screw with mafs off can only bring it down to around 1500. My mafs was tested with multimeter and is good. TPS is good. How do I check the IACV? I think it is a vacuum leak hidden somewhere though. My motor was cleaned out too well by myself when I had it out of the car. It was taken apart down to every bolt. I cleaned the intake mani and iacv parts, so I know they are not dirty.

[unfrgivn]

If you are using a SOHC MAFS then stop... I have your answer. My car did the EXACT same thing and it turns out that the plug goes upside down from the SR harness to the SOHC MAFS. so trim the other side of where the plug fits on and then turn the plug around the other way. Fixed it right up. Hook your boost gauge up and if you aren't pulling vaccum (gauge sits at 0) then that is a good indicator.

[ItzGenX]

Wait, let me get this straight. With the wire colors matched up, the connector needs to go the other way around on the mafs? Today I took all my intercooler pipes off twice, all vac hoses off twice and couldn't find the problem. I even mounted the maf directly to the throttle body and all vac hoses unconnected with my cousin covering each vac nipple etc with his fingers and tried to start it. Same thing. It does a regular startup to a high idle, drops down and stumbles a few times @ 100rpm and then dies. If it is indeed the maf wiring being backwards, then I will try it. I just need to confirm that you have your wire colors matched up with the harness and your SOHC maf connector upsidedown. If this was the problem the whole time, I swear I will go hugging trees.