engine misfiring with stock intake gone, wtf?..
engine misfiring with stock intake gone, wtf?..
ok, so awhile ago I got rid of the stock air box and threw a cone filter on the end of the VAF. Very shortly after I did that after i'd drive the car for awhile and after the engine heated up a bit, whenever I pressed the gas pedal the car would sound like it was misfiring and i'd have a bit of a loss in hp. Car wouldn't accelerate anywhere as near as fast as it did when running right. After a bit of head sheding I realized that I forgot to plug that air regulator thats on the side of the intake box back in to those hoses. I got that off and plugged all the hoses back in figuring that would take car of the problem, but low and behold it still does it from time to time. Anyone have any idea what this is all about? Thanks in advance
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PATDIESEL
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You could be getting an air leak somewhere. When you press the gas pedal all the way down the engine will turn and may be pulling one of the couplings or something. You can check that by craking the car and turning the throttle cable to rev the motor while watching the intake.
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georgechicken
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Are you getting a check engine light? If so, pull the codes and let us know... I've seen this many times, and typically the problem lies either in a broken intake tube (cracks or some leak in the rubber hose) or in the general installation of the cone filter. The intake and filter need to be firmly supported with some form of bracket, or whatever you can come up with to hold it steady. An intake that can just flop around can tear or break the rubber intake hose, or it can jar the VAF hard enough to send the engine a false measurement of intake air and temp. My suggestions:
If you have the engine light on, pull the codes and we'll instruct you from there. If no light, check for a leak in the intake tube, make sure that the round plunger in the VAF is spaced sufficiently from the filter (if there's not enough room for the plunger to travel to both extremes, then that will cause problems), check your hose clamps, and listen for any vacuum leaks (sounds like a light hissing while the motor is running... this can be a tough one if you dont know what to look and listen for). Good luck!
daniel
If you have the engine light on, pull the codes and we'll instruct you from there. If no light, check for a leak in the intake tube, make sure that the round plunger in the VAF is spaced sufficiently from the filter (if there's not enough room for the plunger to travel to both extremes, then that will cause problems), check your hose clamps, and listen for any vacuum leaks (sounds like a light hissing while the motor is running... this can be a tough one if you dont know what to look and listen for). Good luck!
daniel
--Maybe the Hippopotamus was just a really cool Apotamus.--
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georgechicken
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Provided that your car has OBD I (on board diagnostics I, only found on 92 to 95 models) as opposed to OBD II (found on 96 and up), then it's really easy. And yes, all MX-3's have OBD, its not an option, just a government required feature...
Look under your hood and right at the firewall, and to the side of the brake booster. There should be a little black (maybe 2 1/2" by 1 1/2") with a black cap labelled "Diagnosis". Pull the cap off. You'll see that a plug of some sort would fit here. What you will do is take a piece of wire of some sort (I find that a twist tie from a bread wrapper does well and is easy to manipulate), and using the label on the underside of the cap, put one exposed end of the wire (or twist tie) in the pin labelled "GND" and the other end in the pin labelled "TEN". Only do this with the ignition OFF. Now that you have jumpered the two pins, get in the car and turn the key to the ON position (this is the 2nd ON position, the one where all of your dash lights come on...). After a couple of seconds, you'll notice that your CHECK ENGINE light will start flashing at you. take note of the pattern and the length of the flashes. Here's how to interpret the codes. The first digit of your code is indicated by the long flashes, the second digit by short or quick flashes. A long pause indicates the end of that code, and the break between multiple codes. For example, code 22 would be shown as long flash, long flash, pause, short flash, short flash pause. codes 8, 15, and 21 would be 8 short flashes, long pause, 1 long flash, pause, 5 short flashes, long pause, 2 long flashes, pause, 1 short flash, long pause, and then it would repeat the series of codes over 2 more times.
Get it?
it's easier than it sounds, and you'll probably understand it when you see it. Now, once you see the flashes, make sure you write them down. You can either go to the online shop manual here on mx-3.com or you can check with us in this forum if you can't find them there or need more explanation. This will give us a good starting point to finding your problem.
Good luck!
Daniel
Look under your hood and right at the firewall, and to the side of the brake booster. There should be a little black (maybe 2 1/2" by 1 1/2") with a black cap labelled "Diagnosis". Pull the cap off. You'll see that a plug of some sort would fit here. What you will do is take a piece of wire of some sort (I find that a twist tie from a bread wrapper does well and is easy to manipulate), and using the label on the underside of the cap, put one exposed end of the wire (or twist tie) in the pin labelled "GND" and the other end in the pin labelled "TEN". Only do this with the ignition OFF. Now that you have jumpered the two pins, get in the car and turn the key to the ON position (this is the 2nd ON position, the one where all of your dash lights come on...). After a couple of seconds, you'll notice that your CHECK ENGINE light will start flashing at you. take note of the pattern and the length of the flashes. Here's how to interpret the codes. The first digit of your code is indicated by the long flashes, the second digit by short or quick flashes. A long pause indicates the end of that code, and the break between multiple codes. For example, code 22 would be shown as long flash, long flash, pause, short flash, short flash pause. codes 8, 15, and 21 would be 8 short flashes, long pause, 1 long flash, pause, 5 short flashes, long pause, 2 long flashes, pause, 1 short flash, long pause, and then it would repeat the series of codes over 2 more times.
Get it?
it's easier than it sounds, and you'll probably understand it when you see it. Now, once you see the flashes, make sure you write them down. You can either go to the online shop manual here on mx-3.com or you can check with us in this forum if you can't find them there or need more explanation. This will give us a good starting point to finding your problem. Good luck!
Daniel
--Maybe the Hippopotamus was just a really cool Apotamus.--
