Hi guys,



Looking for some help here. I've got a 12A automatic. I got it as a project and have been trying to get it running since. I can start it now, but it is luck of the draw and takes a lot of cranking sometimes (especially if the engine is already warm from running). When it is started the engine sounds good, I think it just needs carb adjusting or something minor. I've rebuilt the carb and have been trying to adjust it, but it hasn't made much difference. Reving at 750 while idling in drive. I'll be the first to admit that I don't know exactly what I am doing, so maybe I am overlooking something simple, or I'm just not adjusting the carb properly.



Its giving white smoke after a few minutes of warming up, and the new spark plugs are fouling up quickly, making it even hard to start. They end up black and crusty but not wet. It tends to stall out eventually.



Any advice would be great. I can't trust this car enough to drive it around the block yet.

 

You may want to replace the coils on it. Sounds like the spark is weak. White smoke might be a coolant seal leaking in to the combustion chamber, also making it hard to start once it is warmed up. Heated water has pressure and force it way past a bad seal seeping into the combustion chamber.



Is it going through water. Maybe put a timing light on the plug wires and see if you are geting a strong flash, which is indicative to some extent. of the condition of the ignition system.



Good Luck.

 

Hey Dude, I too had white smoke.... but this was on a 12A turbo efi. It turns out there was broken wire to the map sensor, this made the computer think it had to put more fuel into the mix. As a result way too much fuel which turned into white smoke. Once this wire was fixed no more trouble with white smoke......



I dont know if this helps??



Cheers



RE-Genesis

 

Update:

I don't think it's going thru water or coolant, but I've only had it running for about 20 mins at a time. I'll look into the map sensor. Can you tell me more about it and how to check it? I guess i should check the timing too.

I adjusted the carb some more, started it a bunch of times. Seems to be starting easier, but still tricky if the engine is warm. I pulled the plugs and they look good now. Started smoking white only once I rev it hard.

When in drive, if I get the rpms up medium to high and let it go back down to idle, there is a very good chance of it stalling.

 

You wont have a map sensor. Map sensor are on fuel injected cars.. Probably going to end up being you carb needing an overhaul.

 

on an automatic theres a modulator thingee on the side of the trans, and a vacuum line to the motor, so the trans knows when to shift.



when the modulator goes bad, the engine can suck atf = big clouds of white smoke



modulator is mazda part number BT07-19-823

 

Thanks for the advice so far.

I think I'm going to need to adjust the carb some more. At least get the rpms up a little more to avoid stalling. Carb is freshly rebuilt.

The modulator sounds like a good culprit. Is there a way to test if it is operating normally? Would I find ATF in the vac hose if it is acting up?