1993 Accord LX 5 speed - intermittent sputter
 

Hello all! I just purchased a 1993 Accord LX 5 speed. 175000 miles. New plugs, wires, starter, and battery. It does have a silly cone style air filter (stock box removed).

I test drove the car and it seemed to run fine. P.O. advised me of a spit & sputter but it never happened while test driving. However when driving home after purchase it started acting funny. Almost as if it was running on 2 cylinders. It does it sometimes, not all the time. I figured out that the stumble goes away after you give the car 1/2 throttle.

Doing some online research, I'm under the impression that maybe this is being caused by the TPS. But it seems strange that it isn't a constant problem. Maybe a speed sensor? EGR? MAP?

Has anyone else experienced these symptoms before? If so, maybe you could lead me in the right direction on where to look.

One other thing...I ran the on-board ecu diagnosis (jumpered blue plug on the passenger side kick panel) and I only get a solid C.E. light. No flashing at all. Is this normal for a ECU with no codes?

There is a consistent problem of EGR system causing a "lean stumble" at 1500-2000 rpm. Problem is caused by selective blocking of EGR ports in intake manifold allowing too much EG into remaining ports and causing over-leaning and miss/stumble at the rpm range where EGR is open.

See attached document on cleaning the EGR system.

good luck

Thanks for the link to the tutorial. I have no doubt this needs to be done. Would these passages being plugged cause this to happen all the time? It seems odd that this problem comes and goes. It could happen on a cold engine, warm engine, going up a hill, or down a hill.

I notice that when I pumped the gas it runs better. Maybe there is something else that needs attention also.

It's not a certainty that EGR port blockage is your problem. However this is a common problem on Accords and relatively easy to fix.

There very well could be another problem. If O2 sensor is old (> 100K miles), we have seen drivability problems cured w/ a new O2 sensor.

If Check Engine Light comes On for 2 secs and goes Off when keyswitch first turned to On, the ECU self check is good.

In later obd1 models (1994), Check Engine Light on Steady w/ service check connector shorted meant no codes stored. I could not find this documented in my 90 Accord manual.

good luck

The CEL on solid when the service connector is jumped means no engine codes are stored. IMO, the sensors are sending a "normal" signal. Do not blindly replace sensors unless you find one that failed by doing some testing.

The EGR valve only operates when the engine is in close loop (normal operating temperature), so this may explain the hit and miss. Cleaning the EGR valve passages would be first on my list.

I may also consider getting a Honda thermostat for your car.

As I was attempting to bleed air from the cooling system I noticed the green wire to the EGR plug has been severed. I'll make a trip to the scrapyard and scavenge one off another accord, solder it in, and see how it acts.

Thanks for the help!!