bad gas milage and runs bad

[tomw2]

I own a 94 Bonneville and ever since I owned it I have gotten bad milage. Also for about a month it has been jerking at takeoff and realy bad when accelerating at highway speeds. I took it to a dealer and they did a diognastic on it and found nothing. There is no check engine light.
I am thinking of another Bonneville 2002 or 2004 and was wondering if gas milage would be in upper 20's on highway. I own a 92 Suburban and my 94 Bonneville dosen't do much better.
Any help will be appreciated. Thanks: TomW

[FormulaLT1]

The newer Bonny's get around mid 20's on highway from what I have heard. Also on the 94 when was the last time it had a tune up?


Welcome to AF

John

[LMP]

Poor acceleration and jerking may be linked to several factors: normal maintenance like spark plugs, plug wires and coil packs....but the last would bring an error code and you know what you did about that maintenance.
Non maintenance items that come suspicious after more than 10 years are the MAF and the TPS. Those are located together and you can get them in yours hands.
www.avigex.ca/xport/tpsloc.jpg
www.avigex.ca/xport/maf.jpg
Make sure the MAF little shiny wire in the intake throat is not covered by a coat of clay: it happened in mine after an air filter "malfunction". CLeaned with alcohol and got back to normal. ANd TPS sensor can be tested with a voltmeter (on the car) or with an ohmmeter - in your hands - for continuity of the resistance track. These tests cost NOTHING and will either clear the problem or clear the way for other tests.
MAF problem may be there and not trig a code
TPS problem would in most cases give an error code 21 or 22 (OBD1) or equivalent for OBD2