soot build up heaver in right exhaust tip than in left side

[joey rodrigue]

I would like to find out what is causing .heavy soot build up in right side exhaust tip. motor seems to be running a little rich. set ing timeing runs good like to get in running a little leaner

[DCaff300ZX]

Welcome!
It's hard to pinpoint such things as you ask from such little information, we'd need a lot more such as test results to various items (injectors/harness/connectors) and more maintenance history to even guess. We are much better answering questions about test results from common areas of failure with the Z32.
On the surface though, soot is generally a fuel-related thing and since all 1990-1994 Z32's injectors fail and the harness and connectors also, I'd start looking and testing there using the online service manual you can download from our "everything you need to know...Z32" sticky. Ethanol in our gasoline and a wiring/electrical issue specific to the Z32 cause this injector failure, along with crappy connector corrosion and harness breakage due to heat.
There are other areas to look at as well such as if your exhaust system is newer and working right (bad cat), if your O2 sensor(s) are working, etc....too many things to go over here, but all is in the OSM along with the tests...good luck!

[amc49]

Could be say leaking valveseal(s) on one side of motor too. Oil soot instead of fuel.

Could even be nothing, one pipe simply having more turbulence at that point than the other.

[evildky]

Or someone deleted the cats. Or the cats are dead.

[NolimitZ32]

or one of the O2 sensors are worse off than the other

[DCaff300ZX]

or one of the O2 sensors are worse off than the other

Yep, very likely so if not a combination of all of the above- The O2 goes intermittent as they do, clogs one cat more than the other working side does, and overall with corroded connectors the Z32 starts to run crappy and all the "normal" old Z32 issues begin, or get worse.

[joey rodrigue]

thanks

[joey rodrigue]

will check 02 sensor connectors. we did find slight corroded connectors for tps and mass air flow sensor

[DCaff300ZX]

Be sure to check the O2 itself as well, they aren't heat-shielded too well for their living quarters and I've also heard they sometimes come new not working quite right as well so it is a worthwhile test.
Overall corrosion of the connectors is a bay-wide issue, and area that is best to completely rework or at minimum service well. The crappy connectors themselves crack/warp/break and are mostly NOT moisture-sealed, causing all the issues and why replacement was my choice for ALL engine bay connectors. This is a car that benefits from over-doing your maintenance runs, as there are so many areas to address at one time or another, may as well take that potential issue (corroded connectors) out of the mix.

[joey rodrigue]

also had motor missing and backfiring at times.replaced crank sensor motor is running good and soot is not as heavy.

[amc49]

Any missing whatsoever or backfiring will soot up a system so fast you won't believe it. And only a very few minutes of it can also start the cat poisoning that leads to an early death. Cats lead long lives by virtue of running with very little unburned matter going through them, once a lot more comes through they push into a melting overheat quicker than spit........the rotten egg smell, which contrary to conventional wisdom is not a dead cat, rather one still working at that time but heavily overloaded with HC to die really fast if the issue is not fixed quick. Why the two ideas get linked.

[DCaff300ZX]

^^^^ Great info here, thanks for sharing!