lean at idle. help please

[phill]

I parked my car and haven't driven it for about 4 days. when I came out to use it the battery was dead. so I charged it up and started the car. The car idles rough and my narrowband A/f says im way lean. checked for kinked fuel lines, and vac. leaks but couldnt find any, cleaned the IAC and checked spark and my walbro pump primes just fine. if I rev the car slightly it will jump to the rich side of the gauge but then falls back to zero. After you rev it the rpms will sit at about 8-900 and then fall to about 200 and catch itself. I'm at a los for what could be happening, any ideas?

thank you.

vehicle is a 1998 RS turbo with walbro pump and 12:1 fmu, MSD coil pack.

 

[VelocitàPaola]

Are there any stored codes? It sounds like you have an electrical short somewhere. Perhaps a sensor is bad as well.

 

[njdaewoo]

Do you have the fog light mod on your car? I'm asking because when I tried modding my fog lights to work without the headligts following a example I believe I saw in the FAQ explaining to go into the underhood fuse/relay box and cut the relay wire for the fogs and connect it to the constant hot wire inside the fuse box. When I tried this it seemed to work perfectly, but after some time passed I noticed my fog light relay was warm to the touch but the car was off. I know this may seem off topic but because of that relay being constantly powered up. It will cause a dead battery if the car is not started for two or three days. I hope this may solve your dead battery issue.

 

[phill]

Pulled the codes today. I have 3

P0113 IAT sensor high input

P0171 system too lean- Cylinders1-4

P0403 EGR control circut


Ive replaced the IAT like 4 times now so it must be a short. I knew the system was lean, and I dont know what would cause the EGR one. Any ideas? Thanks in advance

 

[VelocitàPaola]

Here are a few suggestions from obd-codes.com regarding the P0403 code:

OBD-II Trouble Code: P0403 Exhaust Gas Recirculation Circuit Malfunction

 

[phill]

Thanks, I'm going to pull the EGR in the morning and let you know if it helps with anything. should this help my running lean condition? I know the EGR stops recirculating gases through when not under vacuum, if it is stuck open could it be letting in more air resulting in a bad A/F ratio?

ok I pulled the EGR off and put it all back together and It seems to have helped. Letting the car idle it still stutters every now and then and my narrow band keeps telling me its lean. If I rev it up as the rpms coast down past 1200 the gauge is pinned at rich and then falls back to lean.

 

[njdaewoo]

hey Phill, I would get the AEM wideband asap! The gauge you are using shouldn't be on your car. It could cost you your motor because you truly cant see whats going on all the time. Its like a on and of switch with no in between.

 

[phill]

if I was keeping the car I was going to run MSnS with an LC-1 wideband, but im not so the narrow will work just fine and the new owner will go from there.

If I did the EGR delete should that fix my idle issuses?

Yes i know it will throw a code but I just passed emissions and I already have a test pipe on so I was just wondering if I could plug it up, or make sure its closed then unplug it? Just a thought

Thanks

 

[bullettdsm]

If I did the EGR delete Chould that fix my idle issuses?

Yes !

It depends on why you are having issues, . It is possible that it is drawing air from somewhere in the egr system (back of the intake is a normal situation). So pulling the system and blocking it off, is a possibility.

MB

 

[phill]

rplaced the egr and fuel filter but its atill running lean. What else would make my car do this? I took a video of what its doing so we'll see if I can fihure out how to upload it

 

[96TurboGS]

P0113 IAT sensor high input

I would be concerned about this.

Have you tried looking into the wiring harness along the EGR tube for corrosion/cooked wires? Even checking the continuity from the sensor to the PCM would help. The high input on the IAT sensor is telling you something. That will greatly affect your fuel trims.

 

[phill]

that has been bad since I can remember. I believe its a short in the system but I never can tell. I just get them warrantied out at autozone. they work for a fewdays and then go bad. Anyway, the IAT sensor has never given me any problems.

Like i said the car was parked for a few days had to jump the damn thing and now its telling me it's runing lean. Replaced the EGR valve, then when it didn't fix it I blocked it all off, Replaced fuel filter, Spark plugs, Coil pack. The walbro pump primes fine. there are no vacuum leaks as far as I can see but I am going over the car again tomorrow.

IAT was replaced, fpr is goood and there are no internal leaks in the fuel pump/tank.

noticed this morning that it misses and bogs down at idle on cold starts. warm idle is better but not perfect

 

[Griffeclipsed98]

well this seems a little odd my egr is blocked off and my cel is lite and running p0403 and my car does not run lean at idle. on a wide band test probe i was getting a readying of 14.-15. wich is normal at idle. if you were getting excess air past the tb you would get a idle control code and your idle would be higher than normal not lower than norm. if you have a test light check to see if you are getting a injector pulse at your # 1 and # 4 injcetors, you might have a grounding issue with your injectors

 

[phill]

I don't know what a test light is, where can I get one? How do I use it?

Where is the ground for the injectors?

On another note, I just drove back to college and the 160 mile trip took almost my whole tank of gas. Why would a lean condition result in bad gas milage, I thought it would be the opposite.

 

[phill]

can somebody tell me where the ground is located that is connected with the AIT sensor? thanks