uneven acceleration with 88 Accord LXi (fuel injected)

[dderolph]

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.

Could I test the vacuum advance by disconnecting the 2 vacuum lines from the vacuum advance control? Any other suggestions of how to troubleshoot this behavior?

The distributor was bundled with the vacuum advance control, so I presume I'd be replacing the whole assembly if I can verify that the distributor or vacuum advance control is the problem.

[dderolph]

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.

[wiseguy01]

it should have a magnetic contact the two lines are for advancing the timing when you accelerate therefore when you disconnect them it will run worse because as the engine load increases the vacuum does to thus increasing the timing for better acceleration again everything is vacuum controlled so when you installed the new distributor did you check the timing with a timing light and second you are only supposed to get vaccum off one tube and it should increase as you press the throttle make sure that the vacuum line that increases with throttle is on the right vacuum port cause you could be retarding it example port one is advance and port two is retard so if you have port one switched with port two this can cause problem also take a look at your cap and rotor there should be no burning or cracks if so replace

[dderolph]

wiseguy01, I apprecaite your post but it is not easy to read due to the complete absence of punctuation.

it should have a magnetic contact

I'm not sure what you mean by magnetic contact. Can you elaborate on that?

the two lines are for advancing the timing when you accelerate therefore when you disconnect them it will run worse

Yes, I understand that. But, I believe it should still run smooth and the acceleration should not be characterized by unevenness or pulsing within a certain rpm range. Do you agree with that?

when you installed the new distributor did you check the timing with a timing light

No, but, again, if the timing is a bit off, that should cause a general degradation in performance, not unevenness or pulsing within a certain rpm range, right?

you are only supposed to get vaccum off one tube

OK, but what then is the other tube for?

vacuum ... should increase as you press the throttle

that makes sense. I'll try to verify that, although I think it may be difficult without some kind of instrument to measure the actual vacuum.

make sure that the vacuum line that increases with throttle is on the right vacuum port

I'm pretty sure they're connected right. When I replaced the distributor, I was careful to observe how the lines were connected to the old distributor and then connect them the same way on the new distributor. But, to confirm that they are correctly connected, I suppose I could try reversing them and going for a test drive.

take a look at your cap and rotor there should be no burning or cracks

I replaced them along with the distributor. Still, I'll take a careful look at them.

[Greenblurr93]

was it running fine when you replaced the distributor? what brand did you use? new or reman?

when was the last time you replaced the fuel filter? spark plugs and wires? maybe its not distributor related..