The car accelerates unevenly when the rpm is in the range of about 2200 - 2800 rpm. Above that engine speed, it quickly smooths out. I replaced the distributor in it in Jan. 2010 and I'm wondering whether the distributor and/or vacuum advance is the cause of this behavior. I don't know whether the distributor also has a centrifugal advance. If it does, then I guess that could another possible cause.

I did disconnect the two vacuum lines to see what would happen. With the engine running, I noticed suction from one of the vacuum hoses but I detected no vacuum from the other. But, that may be irrelevant.

A test drive with the vacuum hoses disconnected revealed continued rough, uneven, acceleration in with a certain rpm range, as stated in my initial post. Still, I don't know what to conclude from this. Does the distributor also have a centrifugal spark advance mechanism inside it? If so, perhaps that's the cause of the problem.

 

No PGM_FI light-or CEL on correct? Might not hurt to check for stored codes even if the light is not on or has not come on.

From there, I would suggest a tune up (cap, rotor, wires, plugs fuel filter, ect)

Does this only happen under "load" or while in park/neutral (stick or auto ?)

PS-like to see another 3rd gen owner got a few myself.

 

Correct. The local Advance Auto Parts store will do free code readouts for newer vehicles but I believe they don't provide that service on older vehicles that have older control modules that can't be read by the device used by the stores. So, I'd need to take it to a shop and pay to get a code readout. Might do that if necessary but trying self-diagnosis first.

Cap, rotor, plugs, and fuel filter are all fairly recent replacements.

Yes. I'm still wondering whether the spark advance on the distributors on these older Accords is strictly vacuum advance or whether mechanical/centrifugal advance is also part of it.

I have two Accords. The other one is a '91; it's the one with the higher mileage (~296K). This '88 actually has less rust damage since it's first owner lived in a southern state where chemicals are not needed on highways in winter. So, I"m thinking of some minor rust repair and paint work on it but, first, I want to resolve this engine performance issue.

 

Codes are easy on these, DO NOT pay anyone.

Slide the drivers seat all the way forward. Then from behind the seat look under the seat for a "plastic" cover, on that cover you will see a tab-towards the center of the car- pull that tab from the top and it will fold down. Once down you will see an LED light (red I think?). Turn the key to on/pos II (not running just on). If there are any codes the LED light will begin to blink, count the blinks as they tell the code number. If there are codes, there will be a two second pause in between them or the same one will repeat.