86 Stang with very high Hydrocarbons

[93 LX]

I took my 86 5.0L to the smog shop. I mentioned that I thought it was running rich but the smog guy said he thought it was buring oil and having a mis fire. I have done the cap, rotor plugs and wires. I have not done a compression test yet or looked at the current set of plugs. The CO was well within the passing range just the HCs were way out of wack.

Any ideas on how to track this down? The smog guy said he thought it could be rings ro valve seals but he also mentioned that the cats may be shot as well. They are 21 years old.

BTW the only codes are 44 and 94 KOER no codes on KOEO

one more thing:
both O2 sensors, EGR, EVR Sensor, ECT, ACT, PCV and TPS have been changed. EVP, TAB and TAD solenoids have been replace and with a vacuum guage have been verified working.

 

[Darkwriter77]

You've pretty much picked the same guesses that I have as suspect for the case of Frankenstang's '86 GT 'vert:
- Valve guide seals
- Worn rings (blowby, burning oil)
- Plugged cats (as a result of the first two items)

Also, speed density 5.0's tend to run rich by default, compared to MAF-equipped 5.0's, so that might play a factor, as well.

Maybe try giving the top-end a thorough douche (or two) with Seafoam and/or some throttle body cleaner - hose out the intake, IAC and EGR passages, and make sure your PCV valve screen isn't plugged up solid with gunk (and that the PCV valve is still functional/clean). Frankie's '86 was close enough on its last run after we gave it a full tune-up and swapped on my cat'ed X-pipe that we could probably get it to squeak by just by adding a bit of acetone and maybe backing off the timing a little more - might help with your car's situation, as well...?

 

[FrankenStang]

I feel your pain, man. I feel your pain.

 

[93 LX]

I got it passed by way of.. well you know. I just need to get this running a bit better. I will try to get this damn thing done and maybe for giggles get a H-pipe for it.

Allen

BTW it wasnt running rich, in fact the smog guy said that the fuel management was working perfectly. The smell is buring oil mixed with the fuel. He also said check to make sure the smog pump is actually blowing air. IT turns but I never hear the dump valve dumping excess air on decel.