1988 Grand Fury

M Body General Discussion

  1. CM360

    CM360 Well-Known Member

    Likes Received:
    Sep 18, 2011
    Did anything change with these vehicles since 1980? My 1980 Diplomat is the closest I got to these EPA smog rollers. Found one with 55K. Not sure what Chrysler did or didn't to produce these cars.
  2. BudW

    BudW Moderator Staff Member

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    Mar 4, 2012
    Oklahoma City
    If I understand the question, as to what is different between emissions between your ’80 Diplomat and an ’88 Gran Fury?

    All ’88 M’s got full emissions, except for a very few exports (outside of USA or Canada). That does include a computer-controlled carburetor/ignition system, 3-cat exhaust system (one underneath each exhaust manifold and one by transmission), A.I.R. (aka smog) pump with switching valve (sends air to both exhaust manifolds or to rear cat, depending on computer programming), EGR valve and a charcoal canister (for fuel vapor control). Maybe even a few other emission controls – but the ones mentioned are the more important ones.

    The ’80 could have the same exact system (for California sales), but most '80 FMJ’s would fall under either of these other two categories:
    Light Emissions: Single cat converter (by transmission), no A.I.R. pump system – but exhaust manifolds and/or cat converter would have fresh air sucked through an aspirator valve via hose to air cleaner, EGR valve, a charcoal canister (fuel vapor control). It may or might not have a computer on air cleaner that controls ignition timing (only).

    Medium Emissions: same as Light except it will not have an aspirator valve but an A.I.R. pump system with diverter valves that sends air to exhaust manifolds or to cat converter depending on engine temp (only sends to exhaust manifolds when engine is not yet at operating temp). It may nor might not have a computer on air cleaner that controls ignition timing (only).

    Except for computer controlling ignition system only (if equipped) vs. computer controlling fuel and ignition, the 3-cat system and A.I.R. pump system, most all other emission parts are mostly the same.

    Most ’81 and newer came with A.I.R. pumps and 3-cat system, standard. I don’t know the percentage but would say maybe 50%+ of ’80 FMJ’s did not come with A.I.R. pump system nor with 3-cats.

    If this is what you are asking about, can you elaborate on your question?