I have driven my car a total of 1500 miles since a rebuild and most of my mods listed below. I was running open headers for all but like 50 miles of that. The car ran like a raped ape until one day I was out in the rain and then it started running like crap. When I got the car home all the power steering fluid had leaked out. It turns out that my friend that was helping me didn't tighten the line into the pump up all the way so the fluid leaked all over the front of my motor. My first idea is that the problem is ignition related, but then when I was doing some reading it sounds like it may be the O2 sensors. I think autozone only had one in stock so I never changed the other one. I have to sell my car now and I don't have the money to fix this, but I want to know some things to either check or give possibilities to any potential buyer. the car is not registered so I can't take it somewhere to have it on a scanner. TIA guys.

I also forgot to say that I had a tune done by pcm4less and with everything i'm getting like 11 mpg so I know something isn't right.

 

I take it you don't have a laptop and a cable?? Those are worth their weight in gold when it comes to diagnosing this kind of stuff. Check and see if the problem only exists when it switches to closed loop (warm). Unplug both O2 sensors and see how the car does.

 

Yeah I don't have any of that stuff. So If I just unplug the O2 sensors what will that do? I'm confused on the open and closed loop stuff. Do you think that it may have been a coincidence that when the power sterring fluid leaked all over everything that one of or both the O2 sensors went bad?

 

That forces the computer to revert back to open loop, like it does when it is first started ( Cold ) ... As it reaches temperature, it stops running off preset tables and goes by the readings of certain sensors. By unplugging them, it does the same thing, and you can rule them out.

 

Ok so when the car is cold it is in open loop when it is started up and then goes to closed loop once it is warmed up? If that doesn't change anything what other things could it be or simple things that I could test to rule out other things? Obviously to test the opti I would need another and install it right?

 

Well, figuring out if it is only happening when the car goes into closed loop will rule out a lot of possibilities. It will rule out any mechanical failures, opti, injectors, coil, etc. You are basically left with a few sensors to trouble shoot. The temperature sensor and the O2s are the only ones that come to mind. That won't mean that the sensors are bad though. Like, if the car had an exhaust leak and your blm's were all over the place, the car would run like crap when it went into closed loop and all of the sensors would be fine. Like I said though, it will help a lot if you can eliminate a bunch of possibilities by checking one thing. Also, be patient (don't just start buying parts) and we'll try to help you chase down your problem.

 

Thanks guys I appreciate the help. I wasn't planning on buying any parts unless I got more money. A friend of mine may be interested in the car and I told him about the problem and I just want to have more info to give to whoever may buy the car. If it is something simple and cheap to do then I will do it, but if its the opti I would just let whoever buys it know. I am pretty limited on funds and thats the only reason I am selling the car. Since it was built I haven't even been able to drive it much or even race it which is what I really wanted to do.

 

I highly doubt its the Opti.

A distributer is either bad, or good. It isnt going to be bad once its warm, but fine when its cold.

I think its sensor related, or as he said above me, a mechincal problem DUE TO it going into closed loop, like an exhaust leak before or immediately after the O2s.

Another thing to check is the MAF.

If it was a problem with an injector, it would do it cold or hot. It still has to spray fuel cold, so it would be just as bad then. It would really help if you can get it on a scanner at a garage and have them datastream your O2's, MAF, Temp Sensor, etc. to see what their doing.

 

Well I had open headers on the car until the last day that I was driving it. Isn't it weird that it happened around900-1,000 miles after and it was running excellent before. Wouls just resetting the computer make it any better? I also think that if the sensors were giving false readings and makin it run rich couldn't that be why I'm getting 11 mpg?? I'm not sure what kinda gas mileage I should be getting but I figured that I should be able to get 18 on the highway.