Finally got out today in my 348. Talk about late in the year!! It started perfectly, let it warm up, checked the fluids, etc. Engine rev'd well when I pumped the gas a couple of times. Pulled out of the yard, engine felt good, took it easy, shifted at low rpm just to feel things out. Oil pressure good, temp's up to normal. Took off from the first stop sign and opened her up.....hit 3k rpm and the engine sounded like it had hit the rev limiter. Bobbled, burped and farted but refused to rev freely. Pulled over, turned back to the garage, engine sounded fine, pulled well until about 3k rpm and...same thing. Engine rev's freely when parked, right up to top end. I checked all the hoses, tightened a few loose one's going into the air intake, checked the plugs (they looked fine). Nothing apparent. Any idea's? Car was running fine when put away.
Ideas? Do you see both Slow DOWN lights and both Check Engine lights perform their self-test when you first start your car (4 lights visible in dash)? For a brief *test* only, disconnect both cat ecus in the engine bay (on shock towers). Problem fixed? If problem still exists, replace both engine fuel injection ECU *relays* in the passenger footwell. If problem *still* exists then check both cats for obstructions (Gothspeed sells inexpensive replacements) and test all 8 spark plug wires.
I would start by checking the crank sensors connectors. Make sure they are clean and that the wires are in good shape.
Hi Peter, Have you tired to reset the ECUs. Disconnect the battey for 10 minutes. Then reconnect and start the car. Do not press the gas and dirve untill the fans com ON. This lets the ECU re-learn and calibrate.
Thanks for the idea's guys. Have disconnected the power to reset the ECU's (twice). The air intake was really loose and I thought it may have messed up the air flow so I reset it after I tighted everyting up. No luck The car seems to be ok to rev when it's cold. It's when it heats up it gets rough. Yet when in neutral (no load) it rev's freely. Will check the various connectors/relays as you suggest. Thanks again!
After you check the crank sensors have a look at your spark plug wires. Make sure your plug wires aren't burnt through and grounding out.
Have you check Throttle cable ?? it happend to me once where Throttle cable slipped off from Throttle Pulley and caused Rev issues.
