Running Rich

[el_Don]

I know that ours cars come out of the factory a little rich, but lately I've noticed the tailpipe sediment increase a great deal. I checked my spark plugs and they were dry but had a lot of residue on them. I was thinking it could be the MAF sensor or an O2 sensor but I thought I would have a CEL if that were the case. Any ideas?

Also the only way to alter the ECU is to use a piggyback system or re-flash correct?

Thanks!

 

[fishdonotbounce]

Have you reset the ECU at all?

 

[el_Don]

Last week I unplugged the battery during the process of installing the intake manifold. That did reset everything.

 

[fishdonotbounce]

Hmmm that's really weird. I wish I could help you but the only way I know rich vs lean is my wideband lol.

 

[Tom03es]

Were you getting the tailpipe sediment before the intake manifold install? Do you drive with your foot in it all the time?

 

[P-Funk!]

is your air filter dirty?

 

[el_Don]

Well I always had some sort of sediment like most cars. I do push the car a little everyday (4500 rpms) but nothing really crazy. Maybe I should look into a wideband. I really don't know if it just me being subjective or if there really is a problem. Other than a wideband, how can I check whether it is running rich or not?

 

[Tom03es]

Here's my dyno (shield your eyes from the awesome power output!!!):

It does get pretty rich above 3500 rpms.

Is it getting on your bumper or just on your tailpipe?

 

[el_Don]

Hail the awesome power! (wow)

It's only on the tailpipe, but I'm seriously wondering whether it's just dirt. Unless there's some sign or a CEL I can't go on anything.

 

[ucMP3]

I wouldn't worry about it. All Mazdas run rich and get dirty tail pipes it seems. Buy a rotary and you'll see what I mean, lol. But the FS-DE runs pretty rich as well.

 

[el_Don]

For an update, it seems that the "richness" that I thought was actually caused by oil entering the exhaust and not burning. My car has been consuming a pretty good amount of oil. I ran a compression test today and found that all cylinders were at 160 psi. Any idea as to what is causing this? Thanks

 

[dacquesta1]

get ready for a rebuild....if your lucky its just your valve seals...how many miles are on that engine?

 

[el_Don]

I have 99,745 miles on it. I thought that if I had low compression then it would most likely mean worn piston rings. So with the compression I have right now I'm thinking it is the valve seals. But I'm no mechanic.

 

[dacquesta1]

Does the psi jump up quickly or in many steps?

 

[el_Don]

One man job, so I couldn't tell you for sure. I just gave enough to get about 5 or 6 cranks and then checked the pressure. I was going by YouTube instructions. Should be ok right?

 

[dacquesta1]

Sorry to say it but it was similiar with my fp-de but around 140k, though it seems these fs-de on stock internals sem to go sooner. Hopefully its just the valve seals. Get a set for intake and ones specifically for exhaust.

 

[el_Don]

Glad you told me. I generally like to do my own work but I think I'll be taking the car into a mechanic this time. I'll be sure to let them know what to get. I'll be changing out the timing belt and most likely the water pump while I'm at it.

 

[dacquesta1]

Hey that's what these forums are for. Pass along our personal experiences. Might be right, I might not but its something to keep in mind. Let me know how it goes.