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rough idle/poor acceleration

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my 93 loyale 1.8L TBI (manufacture date of 09/92) is running rough at idle and has poor acceleration. (very poor acceleration from stop) the whole car will sometimes shake at a stoplight. So far I have done the following work to try to remedy the problem; New plugs & wires, new AT Modulator, New fuel injecter, New Distributor cap & Rotor, Checked Timing with Timing Light (20 degrees BTDC) Replaced Intake Air Filter, there are no Check Engine Lights, I did check most vacuum line and hoses for leaks and cracks, and found none. So I am stumped. I did however check the PCV vale last night and when I removed the hose from the end of the valve it seemed to me that there should have been alot more vacuum loss or hissing, but i remember checking the valve out itself and shaking it and it was then rattling just fine.


So again can any one point me in the right direction? the rough idle seems to increase as the engine warms up, however the poor acceleration does just the opposite and seems to clear up as the engine warms up.


I will say that as a mechanic in training, (attending ASE cert school) that I have been spoiled with the latest diagnostics (OBD II, live data) this car doesn't have that capability. which is another question I have, I have located the data link connectors under the hood but don't quite know how to use them. Maybe someone can enlighten me on how the system works and how pull data/ DTC's THANK YOU IN ADVANCE

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Info on the codes can be found here in the USRM http://www.ultimatesubaru.org/forum/showthread.php?t=49918

Hopefully that will get you somewhere better to start with.

One thought popped into my head. Sounds like the EGR valve might stuck open. Check it to make sure its functioning.


good idea. egr valve. is there a specific test that can be used to check the EGR?

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The EGR is located on th pass side rear of the manifold. (it looks like a steel mushroom) Once the car is warmed up, rev the engine a few times and watch the inside of the valve (the diaphram) for motion. If you do not get any motion you may have to run a new vac line to it so you can suck on to make sure it is working. Or you can just remove it for inspection as it probably needs a cleaning anyways.

Pull the codes first.

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