Stock HA running rich.....

[O SO LO]

Took my stock 84 GN and ran on a dyno today---getting ready to change ECM, MAF, Coil/Ign. module, fuel pump, AFPR, etc.--so wanted to get a base line and find any problems before I started changing things...
Well...It pulled hard to 3200 rpm, and then basically fell flat on its face...tech said it was running way to rich--like off the chart...so my question is what's doing this--bad O2 sensor???
I'm a newbie to this--other than LOTS of reading on here...so any help would be appreciated.

Thanks

Mark

 

[Jerryl]

Could very well be a bad O2.
Other contributots to this condistion can be: MAF, bad plugs/wires, wrong chip for injectors, etc ............ Basically, if you purchased the car, you need to question everything someone did. Seen it a few times.
Can you post some scantool data?

 

[O SO LO]

I haven't changed the ECM, MAF, etc. yet to the 87 stuff yet--so I don't have the scan hooked up yet...
I think I will just go ahead and change the O2 sensor--car has 54,000 orig. miles but supposedly sat for a number of years--while I change the ECM, Maf, etc. and then I can check the scanmaster and we can go from there....
Thanks Jerryl