My truck will idle just fine but if i start to drive it has very poor acceleration and wont really go any faster then 30. If you go up a hill its even worse. Eventually when it gets warm it will start to die without throttle intermittently and backfire. I have replace the Icm, the fuel pump. It has 10 psi pressure. The cts. I put a new tps and iac on it last year and rebuilt the throttle body. It has one engine code for knock sensor but it drove fine for years like that. I am at a loss any advice is appreciated.
10 psi is low but within spec. Does it hold 10 psi under load? Overall, I'd like to see 12--13 psi under load and at idle.
Fix the known problem with the knock sensor.
How old are the usual tune-up items and procedures? Cap, rotor, plug wires, spark plugs, O2 sensor, PCV system checked, EGR system checked, initial ignition timing checked, and electronic advance verified, cranking compression pressure tested, spark output power tested with a spark-tester calibrated for HEI, etc?
Connect a scan tool, verify EVERY sensor and computer output. Examine fuel trim numbers.
