We are going to check for arching wires, and also hook the car up to auto tap today and see what the codes are.
After all that we will know where we stand as far as what to do next, our third thought is maybe the dowel pin on the opti may not be in the right place.

When the car is cold it runs "ok", once the computer figures out whats going on it goes bonkers, it idles at 1100 rpm in park, in drive or reverse its at 750-800 and it idles like it has a lopy cam in it, the whole car shakes. Once you give it gas it back fires I'd say about once every couple of minutes its in gear and giving it gas. Just ideling it will back fire eventually.
We have not drivin the car and just "floored it", I'm too afraid to drive it in the condition its in for fear I could damage something else.


I'm a chick by the way fellas, sorry I didn't really make that clear, no harm to foul right???
I just love these cars and workin on them and then goin to the track and tearing it up!!

Greenfire

 

You may want to try new O2 sensors, the ones in the headers if you dont figure out your problem. I had similar issues to what your are having when i had a bad O2, and i got no code for it. They arent used untill the car hits closed loop which could explain why you dont get the problem until it warms up.

 

i say change the plug wires.... the only things that are gonna cause the car to misfire are the opti, plug wires, or the injectors.... if the egr had any effect at all it would be on all of the cylinders. and wires that are a year and a half old are by no means "new" on a car like that... i'm a mechanic and i see bad plug wires every day!

 

I'm sure that the wires can go bad, or in this case maybe cracked....we'll see turns out we have another F-body that blew their tranny out friday night, so its sitting in our garage while mine sits outside. Maybe tomorrow I'll have some news for you all.

Thanks for the advice.


Greenfire

 

UMMMMMM…………..Did you say that you have no rear O2 sensors? I thought OBD2 cars had to have rear O2 sensors?

 

The factory puts them on, but you can take them off and delete them off of the computer. All the rear O2's do is measure the amount of burned fuel and exhaust. They do not affect how the car runs.
The frount 02's are the only ones you need wether its a OBDI or a OBDII car.


Greenfire

 

Testing the car out tonight with the computer to check for the optical lense codes, then the spark plug wires, then if it still runs bad, we have concluded that the dollow pin was not installed correctly, or the opti is just dead after only being a year and a half old. We will see.


Thanks for all your help.


Greenfire

 

Well a little update:

We put the opti back on, double checked to make sure the wires connected to it were correct. Started it for about 15 sec before putting the car back together, ran okay from what I could tell.
Got the car completly back together, started it well now it runs better no backfiring, not shaking like before, but now we didn't realise we let the gas get too low in the tank. We may have ran the gas compleltly out b/c it died a couple times. Got 5 gallons of 93 and put that in, started it now the car acts like its starving for fuel, the rpms are steady at 700-800 when they should be around 1000-1200, when you push the gas pedal the rpms go down and the car dies. We think trash maybe in the fuel filter from the tank, we are going to rent a fuel pressure gage and see what that tells us, may have to change the filter.

Seems like we fix one thing and run right back into that wall again...I feel like a mouse in a maze. LOL!

Greenfire

 

This is our theory on what maybe wrong:

Well we got the majority of the car back together, now the car acts like its starving for fuel, when you push the gas pedal a little. Joe thinks maybe some trash is in the fuel filter b/c the car didn't have much gas left in it and it may have sucked some trash off the bottom of the tank. It wants to die when you push the gas a little. Makes sense to me. We are going to check the fuel pressure tomorrow and see what that tells us.

Good news is the car is not backfiring or any of that anymore so we did make some progress.

the exhuast got hot in less than 20 seconds of running, making me think LEAN.....and if fuel pressure is low due to (bad fuel pump, or filter) then that would stumble when the throttle is opened to let the air in, but the fuel couldn't get in there........sounds good, but there are many other things that could be the prob..........also the coil is a little loose.


Any thoughts?

Greenfire

 

It was the Opti Spark the whole time, car runs great now. Thanks for all your help.



Greenfire