Jump to content


AOAI Forum Members
  • Posts

  • Joined

  • Last visited

Posts posted by CaffeineRacer

  1. My quick guess would be that it has to do with the expansion of hot gases and that you want to put a crossover at a point where the hot exhaust gases have sufficiently cooled as not to cause undo back pressure into the other cylinder bank, but more likely it's probably just an old wives tale. Lol.

    Really though my question is more structural because with the x-frame and the way you route a dual exhaust through it gives you few points where you could crossover between them with out creating another problem.

  2. Really the only thing I can think of that would be different would be an attachment for something like a TV cable on an automatic transmission. Other than that there is not communication between the carb and the tranny. The carb doesn't care what the transmission is doing. I only cares what the engine is doing and how much air/fuel it needs. Buy Cliff Ruggles or Doug Roe's book on quadrajets if you really want to understand them. Doug's much more thorough, but harder to understand IMO, while Ruggle's seems to miss important info so I bought both.

  3. Whatever someone is willing to pay for it!!

    But really. It's hard to say. The Avanti II market is difficult to gauge because it is a car that requires the right buyer which happens to be fewer and farther between than say a mustang. Maybe someone can chip in that has sold an Avanti around that vintage recently.

  4. Most people just do the manifolds as the ceramic coating helps to reflect the heat back into the pipe and keeps it out of your engine bay. Make sure they coat the inside of the manifolds too. The heat levels in the rest of your exhaust system are not quite as intense as they are at the manifolds so it's not as necessary and I would imagine it might get a little pricey.

    So really it's up to you if you want to spend the dough. Are you having a new exhaust made? If that's the case then spend the money on just doing the new one in stainless.

  5. Have you connected a dwell meter up to the MCS to see if it is going into closed loop mode? Do you know how to do this? Check that first then post back and I'll have a couple of ideas depending on the results of that test.

    Also I'm sure you've done this but make sure your base timing is set at 6 degrees advance with the 4-wire connector unplugged from the distributor.

    Also it appears you have a later model ECM. The one that at least was installed on my 82 was actually from an 81 GM system. You can tell the difference because the 81s were the only year where the ecm wasn't set to dry cycle the MCS once you turned the key to on.

  6. Steve great to hear and glad this thread helped. If you have any more ecm or CCC related questions please ask.

    I should also say that in upgrading my computer to a later 1228079 unit and forking out some proper dough on a ZZ4 prom made the car run amazing. This upgrade increases the speed at which the TCC locks up as well as it no longer locks in second gear like it would with the old computer. For me with a 2.87 rear end the lock up at such a low speed would really lug the engine. The spark curve with the zz4 prom definitely has some seat of your pants differences. I'll be curious to see how my mileage goes (if I can keep from foot from being too enthusiastic that is). If you have an early computer I would definitely recommend the upgrade to the newer computer and if you have swapped your 305 to a 350 I'd say the ZZ4 prom is definitely something to consider (it's a little pricey).

  7. So this really would only apply to 81-83 Avanti owners, but where the heck is the ALDL connector on these cars!?!!?! I've searched high and low under the dash and can't find it.

    There is one thing I found under drive dash just to the left of the steering column, but it's only got 5 pins instead of 12 which I thought that all had (maybe I'm wrong). Anyone have any idea or even better actually connected an OBDI computer to their car.

    I'm in the process of upgrading the ECMS in my car to a later 87-88 unit (pn 1228079) which is a little faster and I can use the ZZ4 performance chip I have which removes the EGR and ESC codes, but is still like to check any other codes that might pop up as well as check the sensors in realtime.

  8. I know this is an old thread, but I'm going to give some answers in case anyone else has a similar problem. Numbers refer to the OP original question list.

    1. Yes if you run a 180 or cooler thermostat the computer will never go into closed loop and stay in its "full rich, limp home" mode. The thermostat is the culprit here. Buy a new 195 degree thermostat and you'll be all good.

    2. When you turn the ignition key to "on" the check engine light is supposed to come on to let you know it's working. Then once the engine is running it will turn off, unless of course there are any fault codes. In this case there were no fault codes which is why the CEL would turn off. Again the problem was improper engine operating temperatures.

    3. Yes, CCC cars are programmed such that the torque converter clutch (TCC) will not engage unless the car is up to operating temperatures. This is to pretty the engine from lugging too much while cold.

    Hope this helps someone in the future. The thermostat thing is a common issue with these systems that people over look. Also best way to tell you engine is going into closed loop is to connect up a dwell meter in 6 cycle mode to the bright green MCS lead (passenger side engine bay wall) and measure the dwell. If it is fluctuating then your in closed loop (varies between 10-50ish). If the meter is fixed (probably around 30) then you're still in open loop.

  9. Hmmmm what do you mean by play in the throttle? As in when you push the gas pedal down it doesn't start pulling the throttle cable right away?

    If that is the case yours is just out of whack. Maybe the bracket got bent. Try bending the bracket a little bit to take up any slack in the throttle cable. My short experience is that the throttle cable bracket kits usually aren't quite a bolt on solution and require a little fine tuning in themselves, so I would try to make the factory bracket work first. Also check all the linkages between the pedal to the cable to make sure everything is bolted down solidly.

  10. I just replaced the U-joints on my 82. The U-joints are the same for 65-83 I believe based on the fact the the studebaker international catalog has the same part listed for these years. I used Spicer 5-153x u-joints because they have a zerk so I can grease them if I want. Not sure about the other brands, but I can tell you these Spicer ones are correct.

  11. Oh one other thing. For the rear shocks you have to transfer the mounting tube that was in the upper bushing into the new shock upper bushing. Same deal though you can push them through by a combination of soapy water, hands, and counter hitting.

    What I described above in my previous post about the pins and the grinding is just for the lower mounts on the front shocks.

  12. Drat,

    Go to autozone and get both their small and larger puller. I can't remember which one I used, but I know I used one of them. What I used them for was actually to push the old bushing out. The process for this was I cut one of the ears off of the little figure 8 type mount in there so I could get a good perch on it with with screw on the puller then just screwed the puller down until the old bishong came out.

    To get the new pin and bushing in I actually just used my hands (no I am not a person of superhuman strength). Some soapy water helps with the part and your palm will probably hurt afterwards. I put the bushing in first and then the pin. I think the get the pin in all the way I whacked it on the counter a few times to help.

    The part that I had to ground was the holes in the pins. They are ever so slightly too close together such that the bolts would have to go in at an angle to pass through both the new shock pins and the control arm mounting holes. I just used a dremel with a carbide bit and ground the holes out so they extended closer to the ends of the pin. Take some measurements on the control arm once the old shocks are out then you'll know how much farther out the holes on the new pins need to be.

    I'll keep an eye on this thread in case you have anymore questions.

  13. Well Bob, its on like Donkey Kong now. Just kidding, but for the sake of a lively discussion.

    So I just read through the Holley Avenger manual and I see what you are saying about the distributor and timing control. What are the inputs it is using to determine the timing? It seems like the only consideration for the timing is engine speed.

    In a blown application like we are talking about and your reference to the electronic spark timing being a sort of insurance I'm not sure if this type of system would be much help in preventing detonation and damage to the engine. It specifically states that the kit doesn't use the knock sensor connector (although I don't know why then they put it in the wiring harness). So without a knock sensor the system doesn't know that it should retard the timing if the engine starts knocking under boost. It'll certainly keep the A/F around 14:1 based on the O2 sensor readings, but with the boost they usually seem to tune the engine to run a little rich at higher RPMs.

    With the avenger can you make custom A/F maps? It would be awesome if you could using the engine speed input to also map out a richer fuel mixture so that way as the boost came on you'd be able to prevent leaning and potential detonation that way.

    Also old guys are supposed to be stuck in their old ways. lol :P

    I'd love to pull out all the stops to have an Avanti that ran like it just came off the 2015 assembly line as well, but I also derive enjoyment from working with some of these obsolete technologies like carburetors. There is a real mechanical beauty to them.

  14. I think one of the big reasons is cost. Those kits cost enough, then add in a brand new computer controlled distributor and the installation of a knock sensor and you've just added another $500 to the price tag.

    I agree that having the computer control the timing is nice, but there are still some nice benefits of having fuel injection. Car starts quick on hot days, cold days, and everything in between, fuel mileage goes up, as does engine efficiency and likely horsepower.

    I have a CCC quadrajet on mine and I thinks its the bees knees when it comes to street car carburetors. I get great mileage and performance when I need it. These systems also controlled the timing although the early system like in my car does not have a knock sensor so the computer really just has some preset timing advance curves based on engine temp, throttle, rpm, and O2 sensor input.

  • Create New...