Would this be abandonment?

Why dont you just do this now. When the turbo is fixed/replaced, perform your DOT pretrip inspection.... to the "T". Inspect every aspect of the truck by the regulations. Fill out the inspection report, call the boss & tell him when all DOT defects are corrected, you'll come back to get the truck. He'll tell you to kiss his #$@ and tell you to go home if you dont like the truck etc, etc...
That constitutes him firing you for not driving an illegal truck & that comes under coercion & your scott free. Call the wife & have her come get you.

It'll be a lot cheaper for the owner to send someone after the truck than to fix all the stuff thats wrong with it.

FMCSA Reg 390.5
http://www.ecfr.gov/cgi-bin/retrieveECFR?gp=1&ty=HTML&h=L&mc=true&=PART&n=pt49.5.390#se49.5.390_15
"Coerce or Coercion means either—

(1) A threat by a motor carrier, shipper, receiver, or transportation intermediary, or their respective agents, officers or representatives, to withhold business, employment or work opportunities from, or to take or permit any adverse employment action against, a driver in order to induce the driver to operate a commercial motor vehicle under conditions which the driver stated would require him or her to violate one or more of the regulations, which the driver identified at least generally, that are codified at 49 CFR parts 171-173, 177-180, 380-383, or 390-399, or §§385.415 or 385.421, or the actual withholding of business, employment, or work opportunities or the actual taking or permitting of any adverse employment action to punish a driver for having refused to engage in such operation of a commercial motor vehicle; or

(2) A threat by a motor carrier, or its agents, officers or representatives, to withhold business, employment or work opportunities or to take or permit any adverse employment action against a driver in order to induce the driver to operate a commercial motor vehicle under conditions which the driver stated would require a violation of one or more of the regulations, which the driver identified at least generally, that are codified at 49 CFR parts 356, 360, or 365-379, or the actual withholding of business, employment or work opportunities or the actual taking or permitting of any adverse employment action to punish a driver for refusing to engage in such operation of a commercial motor vehicle."


§390.13 Aiding or abetting violations.
No person shall aid, abet, encourage, or require a motor carrier or its employees to violate the rules of this chapter.