2004 Kia Rio, Starts, Idles, but no power with acceleration
Greetings, and thank you in advance.
Vehicle: 2004 Kia Rio 1.6 FI
Symptoms: While driving, after covering about 125 miles on the highway, having turned off to a secondary road the vehicle lost power. It would idle fine, however when pressing the accelerator, there was no power, it would max out at about 20 mph (floored). It sputters a little when pressing the accelerator and occasionally dies. Stopped the car, self towed to a safe place. The "check engine light" is on, however this light has come on intermittently for months (according to the service department a faulty trip mechanism). It did go in for diagnostics (free, under the table kind) and was suggested that it was a fuel or exhaust problem. They either did not get codes back or were not in a sharing mood.
Weather: It does happen to be winter, with snow on the ground and the car has been out in the cold (though "winterized")
Fixes: 1) Started the road trip with a full tank of fresh gas (with a little STP additive as it was cold out), as such I don't think it would be a fuel issue. (2) Replaced the fuel pump / filter (they are one unit, in the fuel tank, no other filters located in-line). (3) cleared the fuel line with air compressor (the line was not attached at either end during this) (4) Tested the replacement parts / fuel delivery, which appears adequate / steady up to the rail.
Questions: What would be the next most likely and least expensive cause? (the car really isn't worth that much other than being a needed mode of transport right now).
My ideas: (1) Wires / plugs. (2) Distributor (though I am not sure it has one as i can only find listings for the ignition coil). (3) computer or sensors (I am not sure which sensors though ?). (4) vacuum system / hoses? (5) Even though it is getting fuel up to the rail, a clog or problem at the injectors them selves?
Any suggestions / advise greatly appreciated. Preferably in a least to more expensive outlook, tempered by the most probable cause.