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Discussion Starter · #1 ·
When I'm driving my car, the gas pedal isn't very responsive, I have to floor it in order for it to move. Then when I have the pedal all the way down, The RPM's redline and it won't shift unless I let off the gas. And I have to perfectly time it in order for it to upshift, cause when I release the gas it wants to downshift. It does this in all gears. I took it to a shop and had another used tranny put it and it runs EXACTLY the same as before. The mechanic says it's another bad tranny, but I think it's something else. I got the tranny from HUGHES46 and he said it still works and he has an awesome feedback record so I don't think he'd want to mess up his name on here. So my question is... has anyone had this problem and what could other possible things could be wrong besides the tranny?

Thanks
RYZ ROKT
 

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I would look to see if your catalytic converter is blocked..
 

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he wouldnt make it to redline and that wouldnt cause a shifting issue on an electronic trans. equipped car.


the car downshifts when you release the pedal?


this may be a TPS issue. when you got the used tranny, did you get another torque converter as well?
 

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Discussion Starter · #4 ·
ye I have an auto tranny BTW.. but I dont see how it could be the CC... but I have to ease up on the gas for it to upshift but I take my foot off the gas pedal it downshifts rapidly. Yes it did come with a torque converter and what exactly is a TPS issue?

Thanks for the help yall
RYZ ROKT
 

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that would be when you lift off the pedal and the TPS goes open circuit. the PCM sees Vref and thinks youre WOT, causing a downshift. plus overall unhappy performance might point to a TPS.


have you or anyone else ever adjusted it? replaced it?
 

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do you have a remote start or an alarm system aftermarket devices play havoc with any mazda automatic transmission... my cousin put 5 trannys in his ford probe because of a antitheft device. tore it out and three years l8r the car runs great
 

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Discussion Starter · #7 ·
I have a clifford remote start alarm but I never had the remote start hooked up. I never adjusted the TPS nor has anyone else, how could I check it to see if it's still good or replace it. Also my car died the other day while waiting at the drivethru at jacknthebox. Embarrising! I changed the plug wires, still wont start. I'm thinking next is the cap and rotor. This car is becoming a can of worms... I'm thinking of parting it out more and more... but I would really like to fix it...

RYZ ROKT
 

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A quick but not as accurate way of checking the TPS is to connect a wire from GND to TEN in the diagnostics box (just like you are checking codes). If the fan comes on without the gas pedal depressed, the TPS is out of adjustment. There is a more accurate way of checking it and it's in the Haynes, but I don't have that manual anymore.
 

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tps idle timing .. the lot.. from FAQs

How to set idle and timing on the V6
Make sure you have the proper amount of coolant (8 quarts) in your system. Start the car, let it warm up, and have the radiator caps loosened. once the small overflow resevoir fills up, cap it. Watch the filler neck by the pass. side of the engine, squeeze the hoses and burp all bubbles out of the system. Try to just keep the water level up in the neck so it can't suck air back in, and be careful the stuff gets hot! Squeeze the hose till the fluid is all the way to the top(ready to spill out) and cap it tightly. Once you're content all air bubbles are out, move onto the next step.

Why worry about coolant? Bubbles in the IAC are bad and make idle fluctuate in a slow, annoying way.

You NEED a timing light, Without the timing light none of this will work.

Insert a jumper pin between the ten and gnd pins. Hook up the timing light to the battery for power and hook up the signal to the #1 wire location on the disty(make sure all 6 plugs will still get full spark). Loosen the two 12 mm bolts on the disty so it can rotate(not too loose). Now, with the jumper pin inserted, start the car, if it dies, then open the idle air screw on the top of the tb a couple turns.
Make sure the car is warmed up, NO accessories or fans or anything is on, and if the idle is like 1500 then close the idle air screw a little, it should be open 2-3 full turns. Now, move the power steering hoses and wires out of the way, point the flashing timing light at the crank pulley, and watch the small tab on it illuminate and reference it's location to the small timing marks on the plastic tab that sticks out over it. Rotate the disty until the notch on the crank pulley is exactly in line with the "10" on the plastic timing mark indicator(this is 10 degrees before top dead center). Now when it's at 10, tighten the disty down carefully so as not to move it. Double check for 10 deg. btdc. Now adjust the idle air screw until your idle sits right at 650 rpms (+/-25). Turn off the car, remove the jumper pin.

Do not adjust the idle air screw unless the car is running with the ten/gnd pins jumped!!!!!

Now, get your voltmeter. Set it to ohms. Touch the two terminals on the idle air bypass control valve(black part on bottom of tb). The resistance should be 10.2-12.3 ohms. If so, then that is ok. Unplug the TPS, with the voltmeter still on ohms (or continuity check mode), touch the two lowest pins with the terminals of the voltmeter. There should be continuity. If not, loosen the two screws holding it so you can just rotate it, and rotate until you get continuity. Next, take a .006"(.15mm) feeler gauge, and put it between the throttle stop screw and the throttle linkage(back/top of the TB) Before doing that, make sure that the stop screw that the linkage hits JUST barely touches it at closed throttle.(2.5mm allen key wrench for it). Now with the feeler gauge inserted, there should still be continuity, if not, rotate until there is. Next, switch to a .020"(.50mm) feeler gauge in, there should not be continuity, if so, redo the previous step until it is correct.
Plug the sensor back in, turn the key to the on position with a paper clip jumping the ten and gnd pins.Now measure volts, and put the black from the voltmeter on the neg. terminal of the battery, and tap into the yellow(2nd wire down from top of tps harness). Voltage should be between .1 and 1.1 at closed throttle, but I found .5 to be perfect. At wot it should be 3.6-4 volts(check by pressing gas pedal to ensure it opens fully).
Now start the car, your idle will be perfect.
 

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Discussion Starter · #10 ·
UPDATE: after $2,470 spent trying to fix it, a $190 cat converter replacement fixed the problem. IF YOU ARE HAVING THE SAME SYMPTOMS, TAKE IT TO A MUFFLER SHOP AND GET A BACK PRESSURE TEST! Mine was free and my car is back to mormal now.

RYZ ROKT
 
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