Soot in tail pipe?

[CharlieZ]

A fairly recent observation over the last 400 or so miles is a lot of soot in the tail pipe. Mileage dropped from about 43+ to 40/41 in last two gas stops.
All previous driving produced a gray to charcoal color. Car still idles & runs great with no apparent problems. Still uses no oil. Unlike the gray deposits, the soot is like from a maladjusted oil stove.

Any recommendations that may point to the problem beyond checking the plugs?

Thanks.

[kellen302]

burnin' oil?

[FestYboy]

start with checking the plugs, they will tell you what's going on in the chamber

[CharlieZ]

The look plugs pretty normal.

So far the engine has not used a measurable amount of between 3K to 4K mile changes.

[FestYboy]

i see a little oil... try bumping the timing 2*

[CharlieZ]

i see a little oil... try bumping the timing 2*

OK. Now I gotta put some miles on.

I'll post a follow-up later this week.

Thanks.

[CharlieZ]

Just to close this out. I found my timing was way retarded. I advanced it to the limit of the slots in the dist. Could the timing pointer be in a harder place to see?

Starts good. Mileage now 42+. Soot not gone but considerably less. Takes heavy finger pressure to wipe it off now.

Down side is the increased performance. More 'spirited' driving now probably eats into mileage.

Performance was enhanced quite a bit. I don't have any good comparisons. I've only driven two Festivas. This one 90 5spd. and a 92 ATX but now my car feels like it came out of Ford's skunk works! :-)

Thanks for your help FestyBoy.
cz

[FestYboy]

you may be looking at the wrong pointer, also, if you're adjusting the timing as far as it'll go just to get it "right", you've likely skipped a tooth on the timing belt.... look there!!!!

[Christ]

Make sure you grounded the one wire plug next to the firewall/booster before you set the timing. If you didn't, the ECM tries to compensate while you're turning the dizzy and negates some of your "improvement".

[Dragonhealer]

Timing

Make sure you grounded the one wire plug next to the firewall/booster before you set the timing. If you didn't, the ECM tries to compensate while you're turning the dizzy and negates some of your "improvement".

Not only must the diagnostic wire be grounded, but correct idle speed
adjustment must be coincident with the timing you want to achieve.

If your O2 is old, the engine will run slightly richer when in "closed loop",
The plugs should be a little whiter than that. A new O2 sensor will improve
fuel economy some too.

as was noted, make sure your cam timing is correct if you really had to
adjust the dist. to the end of the slot!

[CharlieZ]

I have since set the timing back. While it seem to run pretty good, I thought I detected some pinging when the engine was loaded on hills. Timing is now at 10BTDC.
I did ground the noted connector. And used the correct timing index mark and pointer.
I may look at changing out the O2 sens. Soot build up after 500 miles is still slight.
Thanks for all the input.