MX-3.com

Hey all, so i've got an odd problem and could really use some help. So i have a 92 mx3 v6 gs with a klze swap and curve neck IM no egr. I have not done the ecu yet. But i have had the swap running ok for the last year. The only problem ive had is it idles high (1100-1200rpm) and sometimes when im sitting at a light and i leave it in first with the clutch in the idle going up and down from 600-1200rpm. but i lived with it it was fine.
So a couple weeks ago i was leaving victoria to go to vancouver for the weekend so i went to check my oil. it was good so i left the hood up and started it just to check it over, i heard a vacum leak type of sound and realized that there was a inlet/outlet right behind the throttle body that had a rubber plug over over it that was corroded away, so when i plugged it with my finger the rpm idle dropped way down to 500ish and would drop even lower and almost stall before popping back up to 500. So i was leaving on the the seven oclock ferry in the morning and didnt have time to work it out so i just found something in my garage to plug it and threw the half working old plug in my glovebox. So the car ran good in vancouver all day running all over then at night i was driving right down town and it was at a light the rpm dropped and stalled, so i quickly swapped the corroded plug back on to the inlet and let it idle high as long as it ran till i got home. So i took the ferry home late the next day and went to bed as i had to work early. Well the next morning im driving to work and the car ran ok, until i was headed down a hill in fourth gear clutch out no gas no brake just coasting in gear doing about 50km/h then all of a sudden the car started top jerk really hard like someone who doesnt know how to drive standard, the rpms dropped hard so i pushed the gas to try and stop the herky jerky as im sure it looked bad and that didnt work. so i pushed in the clutch and took it out of gear and pulled onto a side road, i realized once i was out of gear it was idling at about 1800rpm tried driving in second and it would really do anything so i pulled to somewhere that i could park and i got into a spot it died and wouldnt start up again.
so i walked to work and left the car there all day and went back late at nite it started and drove ok home, so i tried again the next day it ran ok to and from work, but the next day the same thing happened twice, once in the middle of and interestion and wouldnt start again lol. so i have been to scared to drive it and die somewhere shitty. so its sitting at home. and i dont want to take it to a mechanic and say i dont know whats wrong please fix it, as that is a blank cheque in most shops eyes.
Sorry for writing such a long post i just thought the back story would help, any ideas thoughts or comments are appreciated.

thanks
Bryan

You could start by fixing that vacuum leak instead of driving it like that for a week.

i did plug it and it made the idle drop to 500 and then would drop to 100-150 and possibly stall.

Try resetting the TPS sensor or adjusting the idle air mixture screw. With the vacuum leak from the corroded cap, your idle was probably adjusted to compensate. Now that its plugged you are getting less air causing a lower idle and using anything that uses the vacuum system would cause it to drop more and stall. Try adjusting those to get your idle up around 700-800, if its still dying then its probably something else.

yea thats a good idea, so im not very mechianical but i feel i could do that. is there a diagram of where the idle screw is?

Your TB is pulling air into your IM through that vac leak. When you plug it, it will then just pull air in through the intake (which is what it's supposed to do). The reason why yours is dropping to a low idle, is because the steady airflow from the vac leak keeps it running, but when you plug it, it shows you that the engine isn't getting enought air throught the intake.

Simply plug the hole, adjust your TPS, and adjust your idle (jump TEN and GRND, while doing so). Check the FAQ section for "TPS Adjustment."

Basically, you need to allow enough air into your IM, through your TB. The idle jump is the give-away for a vac leak.... usually.

Plug the hole and adjust your idle, the idle air screw is on top of the throttle body youll need just a phillips screwdriver.

+1 for Mazdags- I would do exactly that and you should be fine.

ok so i plugged it and adjusted the idle, i dont have a feeler gauge or mutimeter so the tps will have to wait. it does run better. but i noticed one of my spark plug lines has the blue electrical corrosion on the connector to the distributor? so i want to replace the lines. what should i buy? can i do it myself with limited tools and know how?

Yeah, they are easy to change. Just get some new wires and I'd replace them one at a time so you don't get them mixed up.

i cant find a screw on my tb anywhere... help? have 96 stock 4 cyl injected

I dont have a 4cyl but if I did, I would prolly check and/or post that question in the 4cyl section...