Chevrolet Repair: 1988 Chevy p/u. 350 engine TBI, mass air flow sensor, mass air flow

Question
Just purchasing this truck. It is pounding through fule like a wildcat. 1/2 tank for 145 km. Has not passed the e-test yet and I am sure it wont. Exhaust is smelling very badly of the engine running too rich. Am I correct that there may be a problem with the mass air flow sensor (if it has one) or could it be the EGR. Need to have this problem corrected and am looking for advice. Thanks.

Tim

Answer
Hey,

 If it was running too rich you wouldn't smell it.  A rich running motor produces excessive carbon monoxide.  If it was running lean enough to have a lean missfire you might smell hydrocarbons but a rich mixture produces CO.
 You should check the datastream for a defective 02 sensor.  EGR would make it run rough and defective MAFF sensors generally make them run lean.  There will be no way for you to identify fuel mixture problems by guessing.  Most likely causes for bad fuel economy on those motors is a bad 02, defective stat, CTS sensor, ignition timing due to defective distributor shaft. etc

wayne