'Missing' Idle? (with video)

[Aenyone]

1989 944 N/A

It appears that my engine is missing, I have a video of the idle.
Notes: It looks like it is idling where it is supposed to, ~950ish?
The car is warmed up.
I've changed the fuel dampner and regulator.
I've replaced the vacuum lines with the Lindsey lines.
My muffler is aftermarket, but would it make much of a difference?
The cat has been removed, if that makes any difference.
Thanks!

Original Video - More videos at TinyPic

[Aenyone]

No suggestions? Nothing to check?

[HondaDustR]

How does it look under the hood in the dark while it's running? Sparks means bad ignition wires. Are the plugs clean and gapped correctly? Check the distributor contacts and rotor for excessive pitting. It sounds like it could be running rich. That's kind of how mine sounds on first startup on a cold day. Unplug the O2 sensor and see if it goes away. Maybe leaking or dirty fuel injectors or bad fuel pressure regulator/damper. Pull the vacuum lines off the reguator and damper and see if there's fuel in the vacuum side, indicating the diaphragm is shot. Check that the vacuum lines are intact and not clogged that lead to the regulator and damper. Maybe the DME temp sensor is bad. That's all I can think of off the top of my head.

[Aenyone]

I've run it at night, no sparks. I can't guarantee the gaps, but the plugs are only a few weeks old. The cap has been cleaned, no pits. If I unplug the O2 sensor, the idle gets a little worse. Is it possible for the O2 to only 'kinda' work? I know it's old.. probably hasn't been changed since before I bought it. Injectors, not sure. But I replaced both the regulator and dampner because of the leaking fuel problem. DME temp sensor is another option.
Thanks....

[HondaDustR]

Yes, O2 sensors can get slow to respond after alot of use. They slowly get contaminated with carbon. I've seen the recomendation for replacement is 30K for non heated early sensors and 60K for later 3 wire heated sensors. I would run a good fuel system cleaner like seafoam or BG44K and try a new sensor.

[Aenyone]

That's what i will do. Thanks for your help.
I'm pretty sure it's the 3 wire, and I found one for a good price: Amazon.com: Bosch 13011 Oxygen Sensor, OE Type Fitment: Automotive

[Aenyone]

Is there a safe way to test the sparkplugs? To see if there is one that isn't firing properly, due to the wiring?

[kfray]

Remove the plugs and compare to this chart.
Verrill: Plug Color Chart

[rick13]

sounds righteous to me...like a caged lion

[Aenyone]

Originally Posted by rick13

sounds righteous to me...like a caged lion

You know, I didn't think much of it until people starting saying 'sounds like it's missing'. So..

[Aenyone]

Kfray,

I just put those plugs in, would they show signs already?

[kfray]

You could check the plugs after 200 miles of low and high speed driving.

[Aenyone]

So are we agreed, other than rick13, that the engine has a 'miss'?

[Lizard944]

Sounds like a timing problem or injectors. Check the timing marks and check the rotor under the dist. cap to make sure it hasn't lost the set screw and is wandering around. Check injectors. Listen to each one with a stethoscope. Best way is to get a non contact infrared temperature gun and read the temps at the exhaust manifold of each cylinder outlet pipe. Anything running significantly cooler is the offending cylinder that is causing the miss. Pray that it's an injector and not a burnt valve. Try giving the injectors a few whacks, while engine is running, with a socket extension and small hammer to see if anything changes.
Cheers. --Lizard

[Aenyone]

thanks for chiming in, Lizard.
I'm printing all of this stuff out, for reference.

[porsche4life]

Definitely something not right with that motor.

Cat removed won't do that much to the idle, the 02 sensor is before the cat, so the car really could care less... I would consider pulling all the injectors and sending them to WitchHunter Performance - Injector Cleaning & Flow Testing Services, they smoothed out the idle on my Corrado....

[Aenyone]

This may be a dumb question, but...
if the engine is 'missing', it's always missing, not just during idle?

[mayPOR944]

i changed my O2 sensor and notice no change maybe alittle better mpg, O2 only work when heated up to a ceartan point+ they only tell the computer for adjustment when you are crusing not acceleratin. check n clean ur injectors, then plugs wire, and cap&rotor

[HondaDustR]

Actually, the only time the O2 sensor is ignored is during warmup and at full throttle.

[Aenyone]

Ok. During a closer inspection of the wires, I found this little tear. Do you think it may have anything to do with said problem? It's the coil wire...[IMG][/IMG]