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Low idle in reverse?

When in reverse (first detent) idles so low it dies after awhile. Bump idle mixture up? Forward is ok. 

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    aero3113aero3113 Member Posts: 8,929 ✭✭✭✭✭
     I think that sounds like a cable adjustment. If you adjust the idle mixture that will effect when its in forward also.
    2008 330EC
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    Chrisvr6Chrisvr6 Member Posts: 166 ✭✭
    It shifts fine, just felt like it had a hard time reversing away from the launch. It definitely was cold too. Maybe i should've said its a bravo one. It does feel kinda low in forward too. I'm going to try and raise it a bit i guess. 
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    gonna wanna know if we're talking carb'd or EFI... assuming carb because you're talking adjusting the idle 'mixture' (which is actually an adjustment of the throttle arm)- if we're talking EFI and not carb, idle speed is controlled by the PCM and not any adjustment you ought to be making to the throttle body... if that's the case, the mechanism for controlling the idle speed (IAC) likely needs to be cleaned. 

    if EFI: when it's 'cold', it's trimming fuel and adjusting spark off of hard tables (open loop operation), which are factory drafted and non-adjustable... if it's operating in closed loop (after reaching operational temperature), it's operating off of tables created by environmental variables.  If you've reached operation temperature and this happens, I'd recommend you pull the battery cables or the PCM connection, and allow it to rest for a minute or so, to make sure any capacitors are drained and the PCM has an opportunity to drop all the enviro's from it's RAM... which will force it to 'start fresh' and not use and data collected from last season. 

    if carb'd: if you're not idling properly in gear or out, and it did last season just fine, there is a greater chance you could use a good cleaning of that carb- adjusting linkage to achieve the speed wanted is NOT fixing this issue, but instead putting a band-aid on it.  you likely need to clean needle valves and throats with some good carb cleaner, to remove any varnish or gum that's built there over the off season by evaporating fuel... or.. change fuel filters.. the fuel filter will restrict flow and present the evidence of blockage much more clearly at low RPM's... the last thing you wanna do is run that engine lean, and it's pretty easy to do with a carb'd motor.

    just my opinion.   
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    just rethunk this a bit....

    if carb'd, check the autochoke by tapping on it.. its a coiled spring in a black housing on the side and are notorious for hanging up or not setting.  the best thing to do is to press the button on your controls and go to mid-to-full throttle before turning the key to start... this provides a squirt into the throat of the carb, so, you'll only want to do this once, but it also moves the mechanisms- namely the butterfly valve- which can jostle the auto choke mechanism if it's hung up and allow it to function. 

    if EFI it's just about got to be your IAC, because the PCM will send a command to move that plunger to achieve the idle speed no matter what.... just because you haven't tripped a code (alarm) doesn't mean the sensor is running correctly- it could be checking out electrically, but not doing what it's 'sposed to do, which is move that plunger back to let more air in... this speaks of a gummy plunger passage, which is cheaper to clean than replace. 
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    Chrisvr6Chrisvr6 Member Posts: 166 ✭✭
    Yeah, I'm carbed and did a fresh tune up. Cold starts better now with the e3 plugs i think. It has regular non marine fuel in it with a bottle of seafoam too. It was just bogging while reversing in the first detent on the shifter. Maybe once i run it some more it'll get better. The water is still cold and 15 minutes later backing into the slip it did not die. 
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    Chrisvr6Chrisvr6 Member Posts: 166 ✭✭
    Oh, its a 454mag with a bravo one. So not sure theres cable adjusting needed. 
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    if you're trapped to use non-recreational fuel (ethanol fuel), and a carb'd system, you may want to consider installing a hotter ignition coil and widening the plug gaps a bit. 

    I think the stock coil is 35k volts, so, anything north of 40k is good, with 55k being the ceiling before you start seriously cutting into the life of plug wires, caps and rotor buttons.  That spark can jump, which makes widening the gaps on plugs from .045 to somewhere around .05 for 40k coil or .057~8 for 55k coil a good idea- as it gives a larger yet just as hot spark/point of ignition.... 

    i'd only do this on a carb'd engine (not ECM/PCM controlled), ~and this is directed at other users here who might read this and think 'hmmmm'...~ because when the computer is advancing/pulling ignition timing it's expecting a precise toolset to work with... if you mess with that toolset, you're playing with fire (literally, too) and inviting predetonation.... but for us carb'd guys, that wider and hotter spark will allow a more uniform burn and a more powerful exhaust stroke, read: more power. 
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    Chrisvr6Chrisvr6 Member Posts: 166 ✭✭
    Thanks for the insight! 
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