1994 Honda Civic Stumbling

I have a Honda Civic LX 1994 that stumbles on acceleration. It seems to be worse when it is warm. It feels like only one of the cylinders misfires while accelerating, making the car lack power and vibrate, and once the RPMS get high enough, at around 3000RPMS, the misfiring dissapears. Nonetheless, it is a combination of the engine load versus the RPMs, I can get it to stuble at any given RPM setting, if I press on the throttle pedal too hard. Here are the parts I have now replaced:

Entire distributor, including the cap and rotor. Spark Plug Wires Spark Plugs Fuel Pump and fuel strainer Fuel Filter Fuel Rail All 4 Injectors Fuel Regulator Air filter

I have checked the TPS with a multimeter, 0.5V at closed throttle and

4.5V at full throttle smooth transition in between. I have tested the MAP sensor with a hand vacumm gauge and a multimeter, sensor is all nominal but here is the chart if anyone cares to look at it: 0psi 2.80V 5psi 2.34V 10psi 1.86V 15psi 1.39V 20psi 0.96V 25psi 0.52V I have tested the fuel pressure, pressure is normal. I have tested the O2 sensor with a multimeter and propane torch. Again it seems to be normal. I have also disconnected it from the car and driven it without the lambda sensor, still the car behaves the same and stumbles. I have checked the timing with a timing light, and the timing is right on according to specification. The ECM reports no trouble codes. The ECM reports no "Check Engine" light while driving, although the car stumbles wildly. I am running out of ideas... can anyone think of anything else I should check or that could possibly be the reason for the car stumbling.

- JR

Reply to
jrlomas
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You haven't indicated your transmission. Auto or manual?

Might be an EGR valve sticking partly open. Have you checked for this?

Reply to
Hugo Schmeisser

The car has no EGR system. The car has a manual 5 speed transmission.

- JR

Reply to
jrlomas

I've got a '90 Civic doing the same thing. I was thinking that my timing wasn't advancing right. Anybody know what makes the timing advance? Did you try running the car with a jumper wire in the connector for testing the timing? Would that show anything?

-supa

Reply to
supafly

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