Vehicle: 1986 GL, wagon, automatic, hitatchi carburetor.

 

I got up this morning to go to school and it seemed like a regular day. My car started and ran fine. I went to fill up with gas at a station about a mile or so from my house. When I came out and started my car it ran VERY rough and had white smoke pouring out the tailpipe. I drove it to town a couple more miles and it didn't get any better. I pulled over beside the road and checked my spark plug wires to see if they were loose and that didn't help the running rough at all. So I started heading to school telling myself if it didn't get any better I would just turn around and go home. By the time I got to school (20-25 miles) it was running great with no smoke at all. When school was out I came out and started it up and again it ran fine. When I got back to town I stopped and got something to eat and when I came out after 20-30 minutes the smoke and rough idle were back. I drove home and again by the time I got there it was running fine.

 

The pattern I'm seeing is it's running rough and smoking only when cold. I've also noticed the running rough and smoke usually come and go together, so I think they might be related problems.

White smoke is coolant, so you gotta figure out from where. There are water jackets near intake runners under the carb, and where the intake meets the engine. These areas can leak coolant into the air stream, which is burned off. It could also be a head gasket that slowly going out. Worst case, its a crack in one of the heads.

White smoke is coolant, so you gotta figure out from where. There are water jackets near intake runners under the carb, and where the intake meets the engine. These areas can leak coolant into the air stream, which is burned off. It could also be a head gasket that slowly going out. Worst case, its a crack in one of the heads.

 

Could white smoke also be AT fluid?

Yes, it can... careful, ATF catches fire (did on a Jeep I worked on, anyway)

 

Check your transmission fluid. Then yank the vacuum hose off of the vacuum modulator... It's on the transmission, passenger side. Hard to miss, a little round dealie with a vacuum line going into it. If there is any form of transmission fluid coming out of that vacuum line you pulled, the modulator is shot. Replace with a Napa (or OEM) modulator, very easy to do. Just don't lose or forget the pin that goes into the transmission housing!

 

Every time I had a modulator failure (4 so far) it smoked a tiny bit at one point, but worsens to the point you could smoke out an entire intersection....

Here's a little update on my problem.

 

The white smoke disappeared for a few days then came back. But, this time I have made an important scientific observation. The white smoke comes out only while driving downhill. It has been drinking a little coolant but it seems if it were a blown HG or cracked head or intake manifold it would smoke all the time. As far as the missing coolant that might be the radiator leak that I thought I fixed. I've been getting ready for exams and working a lot the past couple weeks so I haven't got a chance to check any thing.

 

If I pull my plugs to check for discoloration would coolant/ATF/oil each have separate distinct colors? How else could I pinpoint exactly what it is?

Here's a little update on my problem.

 

The white smoke disappeared for a few days then came back. But, this time I have made an important scientific observation. The white smoke comes out only while driving downhill. It has been drinking a little coolant but it seems if it were a blown HG or cracked head or intake manifold it would smoke all the time. As far as the missing coolant that might be the radiator leak that I thought I fixed. I've been getting ready for exams and working a lot the past couple weeks so I haven't got a chance to check any thing.

 

If I pull my plugs to check for discoloration would coolant/ATF/oil each have separate distinct colors? How else could I pinpoint exactly what it is?

..I was leaking enough coolant to turn my plugs black..I don't know if you could tell just by looking at the plugs if the leak was very small...here is an easy way to determine a headgasket leak if you have a compressor,... http://realfixesrealfast.com/realfixesrealfast.com/Diagnostics/Pages/Diagnosing_a_bad_Cylinder_Head.html