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84 SDV with 55K orig miles failed emissions

676 Views 4 Replies 3 Participants Last post by  tx_boy_ep
Well I took my SDV to see if it would pass emissions and it failed. They told me it was missfiring and running rich. Well I already changed the plugs a wires that just happen to be he original ones from the factory and I was not able to replace the cap and rotor. I am petty sure that is the reason why it faile cause it is probably the original one from the factory. I tried to get to it once before but could not get to it. I was wondering if any of you guys have a DIY on how to change it and any other suggestions on what else might cause it to be missfiring and running rich.
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Would like to know the HC readings. Unburned fuel either from a dripping injector or a corroded cap/rotor can raise this reading. With the air cleaner off completely, the nuts unscrew from the distributor body holding the cap on unlike any other GM car where you depress the screws and rotate them. It is also very important that the new wires be routed exactly like the originals in the retainers correctly or they will misfire between themselves. Another thing seldom mentioned is the thermostat. If the engine is running too cool, below 195/200 degrees, it will run rich.
Well I found out that my fuel system was running in limp mode cause the computer was fried! My mechanic replaced the computer but now the engine and computer are not talking! LOL I ordered a shop manuel from HELM but it had everything but the engine and tranny so that gave us no help so I have to return it. Is there a schematic or book I can get off the internet to help with this issue?
Forget the aftermarket service manuals and get yourself the factory service manual. They're all over the place on e-Bay and reasonably cheap, too. They'll give you all the info you ever wanted and then some on your car.

Thanks again 77CDV I will grab one of those true service manuels if my friend does not have one at his shop!
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