500Hp 1G Running super rich

[kimper007]

I wouldn't say I am a newbie but I am to this site so here we go. I have a 500hp 1G 2.3L running on ethanol and I am not sure what happened but it just started running super rich (A/F is reading 9.5-10.0 at 3000 rpms) and even at idle it used to run at 16.0 (which is max for my wide band A/F gauge) but now will idle at 14.5 to 15. I have DSM Link version 2.5 and am not to sure where all the values is supposed to be at but since I haven't made any adjustment to it I am thinking its electrical or a setup issue. The only thing else I can tell you is when its cold (has not run in a day or so) it was rev up to about 1500 rpms and then just drop off to about 400 rpms and die or spit and sputter and surge to 2000 rpms and then drop off again. It will do this until its warm.

When I am looking at my dsm link while its running my 02 voltage stays at a steady .04 volts no matter what I car is doing.

When I bought the car last year it ran mint and the guy I bought it from had it tuned at BP performance in minneapolis. I would bring it back to them but they are 3 hours away and I don't have a trailer to get the car down there.

I have checked for leaks and am not to sure whats my next step. I can drive the car but it just doesn't perform half as good as it used to...

 

[Breezio69]

The wideband sensor could be going out on you. If the wideband is set up to simulate the front o2 and its going out it will act exactly like a regular o2 going out. Bad idle, runs rich, afr all over the board, loss in gas mileage etc...

If you haven't touched the tune for a year I'd highly suspect that. Sorry if you posted it, but what brand o2 is it? If its located in the front o2 housing then it very well could be bad, its not "healthy" for it there, especially rocking 500 hp. But others will say otherwise, many opinions on it, I personally run mine 4" upstream from my cat

 

[kimper007]

I am running a wideband NGK Powerdex AFX and it is installed about 2' downstream of the front stock one

 

[little-razcal]

Sounds like it could be a few issues, but it's hard to disgnose something like this without a log, so I would suggest you upload one for us to see.

- From just your description of the issues, it sounds like you could very well have a bad ISC. You should ohm it out and test it for proper operation. These go bad, and sometimes burn tracks in the ecu.
- It also is a almost a definite that your stuck in open loop. This could be from a number of things, but your front 02 reading .04 is a direct result of that. You could very well have a bad front 02 keeping it from jumping into closed loop, or one of the needed requirements aren't being meet in order for the ECU to force closed loop.
- 14.5-15 a/f ratio is what you want at idle, although some people lean it out to get more lope. You are fine with the 14.5-15 and from now on you should really try to target that.
- Your rich condition could be from a number of things and its to hard to guess. If your stuck in open loop and your airflow adjustments are off, you could be seeing the result of improperly calibrated map topped with a meth setup spraying at full song.

CHECK FOR BOOST LEAKS AGAIN, CHECK ISC, CHECK FRONT O2, @ POST A LOG!

 

[kimper007]

I just put a new o2 in the front due to a CE light last year which took care of the the CE light problem. I will try to get a idle log uploaded some time this weekend. I have had bad ISC sensors in other cars and they usually did not stop revving at idle once they got warm they usually continued but maybe I am wrong here. Do you know what factors need to be meet to get it into closed loop?

 

[clipto]

Pm my1gdsm for a great remote tune at a great price.

 

[kimper007]

Looks like I am opening a can of worms with this car, I went to post a log last night and now this thing will not even fire. Just turns over. What's really weird is I am getting 0 oil pressure on my autometer gauge when cranking it over. I think I am going to pull the computer today and see what it looks like inside. On a good note I found two broken wires on my front o2 connecter (red wire and a black wire) but can't see if this helps anything if the car won't start...

BTW does anyone have any suggestions on a line I pull to physically see I have oil pressure, I am sure I do but there that little man in the back of my head saying "just make sure".

I found out that my starting problem is from a blown MPI fuse that is right next to the battery. I replaced it and the car fired once and then blue the fuse again so I am going to look at the fuel pump rewire and see whats going on with that... I will keep you posted as my progress hopefully get further and further along....

Well it looks like I figured out why the car would not start, the MPI fuse bye the battery was blown and that was because one of the two broken wires caused a short which would blow the MPI fuse afteri hooked them back up. Has anyone herd of this and where would these two go then. One I can hook up and nothing changes but the other is the little bastard (one red and one black). By the way the o2 sensor I have hooked up is a aftermarket one if this matters???

 

[kimper007]

I found out last night that the MPI 20A fuse right bye the battery was blown and the cause was the a wire coming from the O2 sensor. I had two wires that were broke right before the factory plug (red wire and black wire) and I jumpered them to the ones on the O2 sensor and for some reason its blows the fuse. I have a aftermarket O2 Sensor but I wouldn't think that would have anything to do with it. Does anyone have any ideas???

 

[kimper007]

Can someone point me in the right direction on finding a wiring diagram for the front O2 sensor, and what wire has voltage or is a ground...

 

[kimper007]

A little update for everyone i finally fixed my "running rich" problem. Seems that my intercooler seams don't hold up very well to 30psi and like to blow apart. Well a quick case of beer to a friendly weld shop and we are back in business. Pisses me off that it took do long to find but I will admit that a intake leak tester is a dsmers best friend. Now to pull that tranny and fix that 3rd gear....