92 Ls Still Will Not Accellerate

[kclm9803]

After removing the exhaust system and checking flow, replacing the Mass Flow Sensor,Throttle Position Sensor and the engine ECM my 92 ls 400 will not accelerate or go up a hill faster than 25 mph. It will drive perfectly and attain freeway speeds but at a glacial pace. New plug wires, battery and air cleaner. Could it be the crank angle sensor? ( I'm running out of things to replace)

[sonyman]

Is your check engine light lit?

[kclm9803]

Is your check engine light lit?

No check engine lite.

[landar]

have you checked for an intake manifold leak?

[ls400manic]

If you haven't solved your problem yet consider swapping out the coils (there are 2) one may be dead. Otherwise one or both of your catalytic converters may in a marginally clogged state.

[Jerry Bransford]

If you haven't solved your problem yet consider swapping out the coils (there are 2) one may be dead. Otherwise one or both of your catalytic converters may in a marginally clogged state.

I agree that the catalytic converter could be/very likely is clogged. Have it pressure tested by a good muffler shop, afterall it's more than old enough to be clogged by now.

[93ls400walt]

I would look at the fuel filters, one undercarriage and a filter screen inside the tank. The fuel pressure regulator and the fuel pump itself. Or just have the fuel pressure checked before any of this to see if the pressure is correct.

You may have code that does not trip the check engine light. Someone may be able to tell you how to check for these. Basically you jump 2 connections in the engine comp. or under the dash OBD. with the ing. on but the car not running. the check engine light will blink codes. long and short blinks. with longer pauses between multiple cycles if you have any. Count the sequence. Example, 4 long blinks = 4. 3 short blinks =3 and vice-versa. Codes are 2 digits. Post what you get. You may want to clear the codes buy removing the neg battery cable for 1-2 minutes the reconnect and drive the car. come back and check for codes.