It's running like crap this morning.

[Embraer]

130,000 miles on it (8K on full rebuild). The car has performed absolutely perfectly in the last 4K miles. No issues at all.

I got home from work last night and parked it outside. We had thunderstorms and quite a bit of rain last night. Anyway, when I went for my Dunkin Donuts run this morning, the car started fine, but when accelerating, lacks power above 3K rpm. It sounds rather tractor-ish, instead of the normal 6 cyl sound. I was thinking that maybe some of the ignition components were wet from the dampness of last night.

I brought it up to temperature, but the misfiring/sound didn't go away. Also, the poor running is hit or miss. For a second or two while accelerating, it will have normal power, but then it starts to misfire again.

I put an exhaust bypass on a few days ago, but i'm still running the stock cat. Also, when I start it when it's cold, the exhaust is cool and wet feeling (IE: gas isn't being burnt, but it's going out the exhaust).

Could a WUR issue be causing this poor performance? Any wisdom would be appreciated! Thanks!

[livi]

Maybe a bit of water/damp under the distributor cap. Easy enough to open and dry. Just a guess, mind you.

[Paulporsche]

How does it start? Any change since the new exhaust component? Does it start, attain a high idle and then gradually go down to idle speed?

It's possible the exhaust is freer flowing and causing your mixture to be slightly leaner than before. Whether that's enough to cause the problem is hard to say, since we don't know where your setting was before.

I'm leaning more to wet ignition, as you said. Are the wires, cap, rotor new w/ the rebuild? If not, you probably need a change. If yes, then a thorough drying may do it.

[Embraer]

when it cools back down, i'm going to dry everything out.

when i start it, it starts, goes to about 1500 rpm for about 10 seconds, then settles at 850 rpm. it is a bit cold blooded (ie, it back fires through intake for about the first 2 minutes of driving it)

since the exhaust change, the starting has been the same.

[azasadny]

Check all of your vacuum hoses, that always caused me issues like you describe until I replaced every last one of them a few summers ago when I swapped the engine...

[Paulporsche]

The fact that the car starts and goes to a high rev shows the AAR is working, although it should probably stay high for about a minute or so, so maybe it is a little out of spec. Check mystery train's thread on AAR repair.

Since it pops when cold, it's possible your cold control pressure is too high, resulting in a too lean mixture @ startup. This means you may need a little knocking of the plug on the WUR.

It's also possible a simple richening of the mixture @ the adjusting screw may take care of it.
After drying out or swapping in new ignition parts, I would try richening slightly. If that doesn't do it, you can always set it back. Just remember where you started and use 1/16 or 1/8 turns clockwise to do this.

[Embraer]

drying everything out didn't fix it. it just feels like it's running on 5 cylinders. i'll check for spark tomorrow morning. i'm taking it to get aligned this week...if i can't square it away, maybe somebody at the shop can.

thanks for the help guys!!

[Paulporsche]

Have them check for vac leaks, your control and fuel pressures, and set your mixture.

[Embraer]

pulled the plugs on it tonight (after doing a quick shutdown, not at idle), and they were all identical...light grey deposits, with no oil fouling. maybe on the lean side. for background on the engine, i'm getting around 2600 miles per quart of oil used.

i was thinking it was running rich (especially since unburnt gas is coming out of the tail pipe when it's cold)......but the plugs say otherwise.

why would the plugs look lean if it was spewing wet gas out of the exhaust on startup? no smoking (black or otherwise)

thanks!

mike

[FPB111]

Are you sure it is "unburnt gas" coming out of the exhaust at startup and not condensation?

[Embraer]

on second thought, it could be condensation....tainted with fuel smell from sitting in there. i might just enrichen it, a tad, and see what happens.

thanks!

[Mitch Leland]

Plus one for Markus, it rained hard, the next morning you had engine running problems, I'd get that distributor cap off, blow it out with a hair dryer and see if that helps.

[Jorasatt]

After one of the heaviest rainfalls in many years a couple of days ago, here in Stockholm, my 2.7 with CIS is behaving exactly the same.

Sounds like it is running on only 5 cyl, but I get a fat clear spark from all 6 when checking. Already tried drying out the distribution cap etc, with no luck.

Naturally curious to hear if you managed to sort it out and how...

Any other leads would be more then welcome.

[Paulporsche]

Embraer,

Did you try richening your mixture?

[Jorasatt]

Another couple of hours in the garage and the old lady is now running as before.
It turned out to be moist or dust in one of the injectors.
I have no idea how the heavy rain caused this, but hopefully this gives you a lead, if you havent already solved it.

Tomas