jim beam <nospam@example.net> wrote:
> delSol-owner@nospam.net wrote:
>> "TeGGeR?" <tegger@tegger.c0m> wrote:
>>> Why do you think you have a misfire? Did you fail emissions on high HC?
>>>
>> When the engine idles the flow of gas out the exhaust is not smooth.
>> There are occasional bursts and stops.
>
> ok, so that's the real issue you're getting at. messing with the ecu
> won't fix that. and diagnostics on the obdcII ecu aren't that
> sophisticated either.
>
> in relation to the exhaust, the gas flow dynamics are not optimized for
> idling, they're optimized for driving. flow will not be entirely
> "smooth". that said, if the flow is worse than normal, it's easily fixed.

How, please elaborate.


>>>> What other options do I
>>>> have? There is no problem with CEL.
>>> Your ECU cannot store or display that information. I don't know how you'd
>>> do it on your pre-OBD-II car.
>>>
>> Can I do an ECU mod? I have seen some info at www.ecucontrol.com and
>> www.pgmfi.org? Any advise on that would be appreciated.
>>
> yes you can, but it's massively expensive overkill and won't fix this
> problem. go to http://boomslang.us/ and read about their conversion
> kits if you want to do it the factory ecu way.

Forgive my ignorance, at boomslang.us I do see parts they are selling
but no docs that explain what to do with them. Do I need the OBD1 to
OBD2 Conversion Harness, and then use OBD2 scan tools?

> getting back to your existing situation, check the ignition system and
> oxygen sensor. non-oem sensors are often abysmal and confuse the heck
> out of the ecu - don't use them. fresh ignition components help
> significantly too because the voltage needed to spark an idle mixture is
> greater than that needed to spark a running mixture. weak or failing
> insulation on the plug leads means it may run ok on the freeway, but
> give weak spark on idle. same for old plugs, worn distributor cap, etc.
>
> lastly, check the ignition timing. when doing it, [with the service
> connector on] check to see whether the timing marks are lashing back and
> forth. if they are, the timing belt could be loose - the ignition
> sensors run off the distributor which runs off the cam. loose belt
> means the whole timing for the vehicle is subject to "noise" and again,
> that affects smooth idle. correct valve lash helps too.

A friend has offered to let me use his timing light, is that
the best way to see what's happeining with ignition timing?