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naviathan

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Posts posted by naviathan

  1. Riiiiigggghhhhhttttt..... Sure there's more to it than fuel metering, but in order to properly use what ever else you've done you need proper fuel metering. Throttle Body injection can cool the intake just as well as a carb and at the same time meter fuel better. With the proper sensors and a decent knowlege of engines and how they work you can setup an EFI system easily and more precisely than a carb ever could. Lets put it this way, if you're smart enough to install and wire it up, then you can do the programming with minimal issues. Carburation has long since been obsolete and unnecessary. It's often used now because it's cheap and you can find almost anyone to set it up with nothing more than screw driver for tuning. Multiport is more involved, but it's more precise. You get fuel injected at the valve instead of at the intake. Your intake can be smaller and formed many different ways. Runner style intake are great for multiport as the runners can cool the air while the fuel is injected toward the end given time to atomize and properly mix into the cylinder. He didn't ask which was simpler to setup, he asked for pros and cons and which was best. Multiport EFI is the best for metering fuel accurately. It's difficult to wire up, but easy to tune as you pull up a laptop and plug it in. Everything else is as simple adjusting and watching sensor readouts. How do you adjust a carb? Oh yeah, turn a screw, run it. Pull the plugs, check the color, turn the screw, run it, check the plugs, turn a screw....etc....Not to mention in order to properly tune a carb how many sets of plugs do you go through? Once they're flooded or burnt they're not reliable sources to read anymore. Color Tune helps a great deal, so what happens when it get cold outside? A carb doesn't know it's cold. it dumps the same amount of fuel. What about when you drive through the mountains? A carb doesn't know the alititude has changed... Guess what....EFI does. It senses the changes in the exhaust and the intake and adjusts accordingly. Which would you really rather have?

  2. Although I'm not a 300ZX guy, the popular Engine Management for the classics is Mega Squirt n' Spark. It's cheap and well thought out. it can be wired into an existing harness or you can create your own. There's A LOT of custom aftermarket ECUs out there. Search around for engine management or fuel management and you'll find a lot. I bought an Electromotive TEC3 system while I was Iraq because I had the money, but it's an extremely pricey setup. Read up on the systems and make sure they'll do what you want. Consider the level of tuning you want to do.

    Multiport injection or Throttle Body?

    Do you want syncronous injection or batch fire injection?

    Do you want a wide band O2 for fine tuning?

    Do you want a single unit to control fuel and spark?

    Do you want coil packs and crank trigger or distributer and single coil?

    MAP Sensor or Mass Air Flow Sensor?

     

    There's a lot of things to consider and make sure that what you want is supported by the ECU you're buying. After market systems a fully programmable so there is no need for a chip or performance anything, you make it do what you want it to. Weigh your options carefully and consider where you might go in the future too. If you buy an ECU now based on limited funds and later decide you want to do more and can't, you end up spending more money than if you just bought what you needed to start with and added on later.

  3. Oh sorry about that, I thought hit the quote in reply. I meant mikes comment on keeping the water pump running as well. Probably not, but I wasn't sure. No offense taken either way. Just wanted to clarify that I didn't mean the fan should run constantly, only until it cools off the engine.

  4. I'll start with your temp issues. Could be the thermostat or it could be a malfunctioning sending unit. I would replace the both of them at once as they are both cheap items. Typically if the gauge goes bad it won't read high, it'll drop low. The high idle won't be due to temps as if it's actually running that hot the fuel will start to vapor lock and it will run rough and low idle. I would suggest checking for vacuum leaks around the intake. More than likely it's the intake/exhaust manifold gasket that leaking. Also check the rubber boot that connects the AFM to the throttle body. it should seal tight around the ends and not have any holes in it. Stretch the rubber out as you're checking it and look for pin holes from the rubber dry rotting. For clearing out the emissions junk, it won't really increase the power any, but a lot of people like the clean look better. You can remove and cap off the egr valve on the right side, the auxilary air regulator (only used for cold starts), the cold start valve, and the high idle diaphram if you don't use/have the AC. If it gets cold you may want to keep these systems as they do help a lot when starting your car in the morning.

  5. Carb - Easy to install, does the job. - Poor metering and difficult to tune.

    Throttle Body - Injection - Single nozzle spray, atomizes fuel well, simple wiring. - Hard to get precise fuel in each cylinder and relies heavily on intake design.

    Fuel Injection - Multiport - Awesome control ability, easy to manage and tune. - Difficult to wire up.

     

    Overall multiport fuel injection is the best so long as you get proper sensors and a good ECU to control it.

  6. Hmmm, yeah that would be cool. A timer with a switched and hot lead that triggers when the switched is dropped and it starts it's countdown then kills the output. That would be pretty cool. To keep the circuit simple and not pull a lot of power through it you could use a relay to make the connection to the fan, but trigger it with the timer. I could come up with something like that. Wouldn't be hard, other than figuring the timer circuit, but I think my Master Handbook or 1001 circuits has a design for that.

  7. IMO you should connect the fan to a constant hot off the battery. When you shut the engine down it's good to keep the fan running to help the water cool better and keep the convection currents flowing. Otherwise when you shutdown (yes I realize the stock system is like this) the engine continues to heat the water until it reaches a certant point then cools down. This has actually caused a problem for me when I was traveling. The engine would get too hot when I would stop for gas and it wouldn't restart when I got back in until it cooled down some. Just a thought. If your battery is good it should be able to take the fan running for a few minutes after shutdown.

    • Like 1
  8. Ok, Flexalite controllers work good as do Flow Tech which is an Auto Zone brand and the fans that are commonly used are from a Ford Taurus.

     

    Please get rid of the tilda (~) marks in the title of your first post. Things like that make the search function useless when someone else is looking for this information. Also, this has been covered before so you might want to try it as well.

  9. From the problem you have described, I do not think you have a relay problem. The running light's are all tied into the same circuit. All four corners would be getting power then.

    Have you checked the brake pedal switch? Perhaps the filaments in the bulbs in the right side brake lights are burned out? That would give the appearance of only the left side being on.

     

    Hmmm, this statement only sounds slightly familiar....:rolleyesg

  10. The pistons are definetely aftermarket, but they could be standard replacements. The cross hatching in the cylinders looks good, but doesn't look like it was machine bored. It reminds me of a quick hone job with a drill attachment. The white stuff is usually caused by coolant getting into the cylinders. My bet would be the engine blew a head gasket and the PO (one of them) rebuilt it himself using autozone parts and just did a crappy hone job to smooth the cylinders out. he probably slapped cheap rings in it and then ran the piss out of it before the rings had time to seat giving you all the nasty oil build up. The dings in the cylinders are definetely from the valves. It appears he caught it in time to keep from damaging anything though. Doesn't look like anything special. If it was over bored the pistons would have a metric number indicating the amount over sized they were on the top and I don't see anything like that. Sorry to burst your bubble, but they're not anything special and I would recommend rebuilding it as who ever did it last time probably had no clue what they were doing and used cheap parts.

  11. Check your injectors with a multimeter. They are negetive switched so you should have a constant hot on one side and a pulsed ground on the other. You don't always hear the injectors and if the engine isn't starting then you won't here them. Make sure you have that hot side. If the hot side isn't there then you could have a bad efi fusible link or a bad efi relay.

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