Accelerator problems I have a 93 legacy and it doesn't want to accel until it reaches a high rpm. We've replace the air filter, fuel filter, pcv valve, wire plugs, and spark plugs. still having the issue. My father is a mechanic and is having issues diagnosing the problem. Any ideas
Cars & Trucks - Subaru - Legacy - 1993 Subaru Legacy
Answers & Comments
Hi,
If you have the turbo charged version, this issue refers to the "turbo dead zone" between 3500-4000 RPM. This refers to the no acceleration between these two RPMs and is caused by the time difference between the time the second turbo kicks in after the first turbo has activated. If you are referring to acceleration loss/delay below 3500 RPM, the issue is "turbo lag" which pertains to the delay in time between the stepping on the gas pedal and the 1st turbo activating.
In some other instances including non-turbo versions, the problem may be due to air leak in the intake manifold and the air cleaner. In the turbo versions, it would include the in/out junction of the blower including the clamps.
Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.
Good luck and kind regards.
Thank you for using FixYa.
Hi again,
On checking if the manifold has leak and if it lays flat to side of the cylinder head, I pour water (with the engine running) on the manifold/gasket/cylinder head sandwhich. Ensuring that no water reaches the plugs/ignition system, if the engine dies, water was seeped/drawn into the combustion chamber, therefore there is a leak in the manifold/gasket/cylinder head.
Other possibilities include (but not limited to):
1. timing off at the distributor;
2. low fuel pressure/weak fuel pump;
3. injector/injector pump needs cleaning/calibration;
4. defective/torn air filter and/or its rubber gasket/seal;
5. cam timing delay/offset;
6. worn out valves.
In one of my bikes, it was leak on the vacuum hose that opens/closes the fuel safety valve.