90 accord manual LURCHING BAD
 

90 accord sedan four banger stick-shift...

Car accelerates well and sometimes drives steady just fine but usually after driving steady for a little bit, it begins to lurch badly. My daughter can get on the gas harder and it pulls fine then goes back to lurching at steady speed. Sometimes it will clear up after a few pull/steady cycles and will be fine until she shuts it down.. Other times it will not clear up at all.

Car has new ignition and tune up parts. Fresh fuel filter. Timing belt and all related to that and water pump replace.

She says it has had this issue for longer than other repairs and this was not affected either way by any of the other work.

What is most common cause?

TIA,
Brent

Are there any stored codes? Is this in the rpm range of 1700~2100?

I would say that is the rpm range iirc.

In fact, tonight as I drove it to be sure the brake line fix was good. It sat a couple months or so. I ran it in first gear to the end of the road to turn around after my last hard braking test. It went to lurching and bucking in under 300-400 feet at about that rpm range.

Brent

so is this only as it's warming up to operating temp from a stone cold start?
If so, my '93 does that for (only) about a minute starting ~30 seconds after I fire it up in the AM; learned to live with it - 40,000 miles worth .

someone told me it's a sticking hi idle control valve.

warmed up for the most part. Usually has built some heat by the time she first levels off on the pedal.

i have the same problam with my accord interested in what this might be

Partially blocked EGR ports might cause missing at steady speed on warmed engine. EGR flow is not enabled until engine coolant temp is warm.

See DIY posts for procedure to clean EGR ports.

Have distributor cap, rotor, and wires been replaced?

good luck

TX-you knew where I was going....:) Thank you sir.

In my case, The car has new "main relay" and all new cap, rotor, wires, plugs and coil.

Problem esisted prior and after with no change from other work. I am guessing I will start with a DMM check of TPS and go from there...

I also suspect (sound of exhaust and exhaust leak at manifold) a clogged cat con.

Brent