I have spent hours, days, and dollars trying to fix a lumpy idle that almost (maybe is) sounds like a miss at idle.
I recently put a 1999 B20B into my 1997 Civic EK. While it was out we replaced the timing belt, water pump, and tensioner.

The car had a OBD1 Pherable ECU with a 93 octane tune and a jumper harness. I have a used Honda distributor, 240 injectors all checked and cleaned, new cap, rotor, NGK wires and plugs.

I have checked for vacuum leaks, cleaned the IACV, tried 2 MAP sensors.
The car runs very well under load and through the power band and does not seem to have any hesitation.

The car still seems to have a "lumpy idle" though at idle about 700-800 after it warms up.
It "smells" rich

I was also told this could be because of the tune at idle and perfectly normal.


My concern is that today I put a timing light on the car and despite the distributor being completely rotated back (toward the firewall) I was unable to line up the timing marks. Another concern is my dads timing light is about 40 years old and the detector lead is a stripped wire I put under number 1 wire on the distributor.

I did not do the timing belt and have not had a chance to check the marks yet (im doing that in the am)

I also have another distributor I may try as well if the timing marks are all lined up.

I also have a slightly bent power steering pulley I'm not sure if this matters.


I have no check engine lights and really no issues above idle; even the gas mileage is good.

My questions are:

What is the best way to check TDC the white or red mark on the crank pully?

If I do have to adjust the timing belt what is the best and easiest way to do this? Is there a way to do this with out removing the lower the crank pulley and timing cover.
If it is off its only a tooth or two.

Could this be anything else including valve lash? Bad timing light? Needs a dyno tune? Distributor?

Thanks

Dan

 

I have the same issues. Hope you get an answer soon. Might help me out too.

 

You have the same issues? Have you done a valve lash adjustment?
I also unplugged my IACV the other day and it seemed to stop the lumpy idle just hunted a bit.
What ecu : chip are you running?
Lets figure this out!

My timing belt was off and since being corrected and timed to the 3 red marks with the light at 0 it seems to have a loud tick tick at idle
When I fully retard the dizzy it smooths out but does not run as well.

 

Could be a burnt exhaust valve. Very common issue with B20's. Usually caused by tight valve lash, and usually causes a rough idle.

 

The base map u got on the Ecu has timing and fuel added to it ... Since u moved the distributor it will throw off what ever is in the tune .... Try a stock Ls Ecu and set ur base timing and ignition timing and see how it idles

 

I'm also thinking my valve lash could be super loose they are pretty noisy right now

 

What if my timing belt is on at TDC but I was not installed during the compression stroke (valves all closed)? After seeing the tooth off there is nothing out of the question and I will be doing my own work from now on. Does not pay to be lazy!