My 94 Blazer I bought about a month ago seems to be low on power while accelerating. While at idle I can feel the vehicle kind of wobble. When I get up to highway speed it has a slight surge or buck. I have replaced fuel filter, plugs, wires, ignition coil, MAP sensor, air filter tested intake air temp sensor and the EGR valve looks like brand new. It also seems to be sluggish on shifting especially into overdrive so I serviced tranny. Perhaps it could be throttle position sensor? Or IAC valve? Thank you for any help.

 

If the check engine light is on, follow the correct diagnostic flow chart to diagnose the problem. DTC's never tell you to replace a part, they tell you what circuit malfunctioned, and you need to troubleshoot it. If the check engine light is off, the system and the sensors are working properly.

First thing with your 94 CMFI is check fuel pressure and leakdown. Most auto parts stores rent/loan fuel pressure testers, and sell them for around $40. When you have one available, let us know and we can walk you through the tests.

 

Thank you. I will get a pressure tester and go from there.