Rookie mechanic seeking help

Engine, Transmission & Driveline

  1. rockstar

    rockstar New Member

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    Hello all - I've just bought a '73 Polara to use as my daily driver. Well . . . kind of - I live less than a mile from work, and can walk to the office in the time it takes my car to warm up and drive in, and considering how hard short trips are on cars, I plan on doing the walking, so it's more of a weekend driver.

    Anyhow, I'm not yet much of a mechanic. All my cars have had common issues from failed alternators and starters to one that needed a brake overhaul, so I'm really learning this as I go. I bought a '66 Dart which has been sitting in storage for the past few years waiting to be restored with the intention of using it as my hands-on mechanical education (which came with an extra motor and transmission and a box full of random mopar parts as extras). However, along the way to restoring the Dart, I came across this Polara and picked it up almost purely as an impulse buy, as it ran, had no floor or trunk rust, and best of all - the seller took $1,000 for it, which I could produce without doing any saving up or budgetting for it.

    Here are the following problems I'd like to get the experts' opinions on:

    a) Power fluctuations - sometimes it runs well, sometimes it sputters. It stalled once on me at a major intersection, but started up again right away. It frequently requires VERY slow acceleration (like 1 mph/s/s) or it feels like it will stall if the accelerator is pressed too hard. Other times it's nice and responsive, and I can push the accelerator to the floor as the front end lurches toward the sky. I've changed the oil and the plugs (and checked the cables in the process), as well as found a problem vacuum hose that kept coming detached. Since addressing these, it seems to run stronger more often, but still has too much time spent underpowered (honestly, I'd say about 50/50). Since it's a 400, I've been pumping premium into it, so too-low-an-octane can be ruled out, too. I've bought a fuel filter which I hope will solve the problems, but would appreciate any insight on anything else that might cause inconsistent power.

    b) Iffy transmission - sometimes when shifting to drive or reverse, the gears don't engage and I'm stuck in neutral and have to re-attempt the shift into gear. Other times it will find its gear but it seems to engage with a little too much force (it shifts hard enough to feel the car jerk slightly). Occasionally when accelerating from a dead stop, I'll have very sluggish accelleration from first into second. When travelling at speed it shifts fairly smoothly and responsively (at least when the engine is cooperative enough to get it up to speed). The fender tag says I have a 904 automatic on this car. I really hope it's something simple like a bad linkage cable and not a failing transmission. Since it doesn't always shift from park, I hope the cable's the cause, but does the linkage cable have anything to do with the sometimes sluggish acceleration from a standstill? I've always been skeptical of additives, since most of them seem to cause more trouble than they fix, but would any fluid conditioners or thickeners help here?

    c) The car doesn't like cold starts. It fires up extremely smoothly with starting fluid, but I've been told the horror stories of starter fluid (I don't spray it down the carb's throat where it can disolve oil but rather spray it all around the intake so it's starting on the fluid's fumes and not the concentrated liquid). Once I've started (with fluid) and driven it to my first stop, it will start on the first try for the rest of the day, at least unil the block gets cold. I plan on changing the starter too, but would like to skip that step if it's unecessary.

    d) I hear a rhythmic ticking noise from the driver's side of the engine, which is relative to engine speed. I once overheated a LeSabre, which burned out its valve cover gaskets, leading to a similar-sounding rocker arm noise. This car hasn't overheated, and the noise wasn't audible the first few runs. A local exhaust shop felt I had a crack in the exhaust manifold but couldn't locate a crack anywhere. I've picked up both valve cover and header gaskets, just in case they've burned out. Any other ideas on how to address this noise?

    Sorry for being long-winded - I've learned it's best to be thorough the first time around.

    :newbie: Once again, I'm largely a newbie at this. I'm in my mid-20s and didn't get to grow up with fun cars like this, and my family drove mostly new cars with no projects in the garage to learn on. Most of my mechanic "knowlege" is from what I've read or been told, and as such, I always seek the advice from those with experience (street smarts always trump book smarts). Please explain the why along with the what to help me further understand what's failing and how to correct it and prevent it from happening again.

    All in all though, the car has been a blast to drive and work on. I drove it home 50 miles from where I bought it, and have since only really driven it to the grocery stores and parts stores/garages, so I haven't had much opportunity to have fun with it, but at the same time, I don't plan on doing much with it until I've gotten its kinks worked out.

    Some pics for those interested (yes, paint is in this car's future):


    The car's most unflattering angle (the other side has no Bondo and only limited rust - fairly impressive for the age!)

    Polara.jpg

    A peek under the hood (the wiper fluid reservoir is a goner, but the rest is still great!)

    Polara engine compartment.jpg

    A tiny pic from the front

    Polara Front.jpg

    A tiny pic of the (nearly perfect) interior:

    Polara Interior.jpg

    Thanks in advance for any help and advice! :)

    Polara.jpg

    Polara engine compartment.jpg

    Polara Front.jpg

    Polara Interior.jpg
     
  2. rapidtransitrick

    rapidtransitrick Active Member

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    maybe check the carb out, make sure the choke is opening up. maybe if the car sat for a long time certain thing with the carb are sticking . could cause you to be dumping fuel and you get your power when it finally cleans itself out
     
  3. Valvebounce

    Valvebounce New Member

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    I'd definately be putting an overhaul kit through the carb, or swapping it out for one that is known to be a good runner.
     
  4. Fratzog

    Fratzog Old Man with a Hat

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    Nice ride and keep us up to speed as you fix it up. I was always under the assumption that 904 transmissions were mated to small blocks while 727s were mated to big blocks? That was the case in 1970 and earlier Polaras and Monacos. I'm wondering if your powertrain got changed out at some point? I've seen that interior before and I believe it was part of an optional package but the name escapes me (Aztec?). I'm in my mid 50s and like you know enough to be dangerous. I'm going to assume that you checked the tranny fluid level while it was warm and idling in neutral. My 2 hobby cars may sit up to 2 weeks (or longer in the winter) before they get started and the reluctance to go into gear when first started is not uncommon. What I do is shift though R-N-D once then select the gear I want and it will go. The old trannys don't like to sit too long. Again if it's been sitting a long time I need to pump the gas 4-5 times before starting. I've been told that fuel will drain back past the the fuel pump over time. In any case I'd recommend you get a factory service manual (assuming your motor is still original).