TheSamba.com :: View topic

Wed Jul 30, 2014 3:02 pm

I know this has been posted to death, and I've read most of them and can't find a similar case. Most people have smoke on startup only. I have smoke on startup, but also when the car is fully warm and idling. So, sitting at a red light, the smoke slowly starts creeping out. Then when I start into first I get a big cloud. The smoke goes away after a few seconds. Other than the smoke it seems to be running well.

This is on a 1600sp, stock 30 PICT 1 and stock distributor. Recently replaced points, rotor, condenser, cap, plugs, adjusted valves, cleaned carb and put in a rebuild kit, and did not have smoke. I was either leaking or burning oil (no smoke but had to top off frequently) at that point and did a compression test. I was low on all 4, and all 4 got improved readings by squirting in some oil. So bad rings right? I was swapping my transmission, so I also put in new clutch kit, flywheel, flywheel seal, transmission mounts, piston/cylinder kit, intake manifold, readjusted valves, cleaned and reinstalled all tins, compartment seal, lots of gaskets, and so on... Now, my valve faces had some pitting on them-- which leads me to believe I need to have the heads rebuilt. But they were like that before with no smoke. BTW, carb jets are 125 main, 55 idle (idle solenoid removed), and 125z air correction.

After putting everything back together and driving for a bit I started noticing the smoke. It doesn't seem to happen every time I drive, or at least not enough for me to see it from the driver's seat. I'm going to go do a new compression test while you talk amongst yourselves. Thanks in advance for the advice!

Wed Jul 30, 2014 3:29 pm

On the piston and cylinder assembly...did you 'clock' the rings?

Wed Jul 30, 2014 4:13 pm

Yeah, I put the gap in the oil ring opposite the flywheel arrow and the other two gaps about 120 degrees apart from the oil ring gap.

I'm compression testing now, but ran into a problem. The adapter on the tester unscrewed and is still in the spark plug hole on #3. I screwed an old spark plug into the adapter with some thread lock. I'm waiting for it to dry, and for the head to cool.

Hey, I thought of one other thing. I changed from a 120 main jet to 125 when i did everything else. But I wouldn't think a main jet would have an effect at idle. Here's what my plugs look like though:

Wed Jul 30, 2014 4:58 pm

White smoke is gas, not oil. If you rebuilt your carb, you probably replaced the float needle valve. New ones are almost always junk. Re-use your old valve.

It sounds like your fuel pump is overfilling your carb float bowl at stop lights, and you gradually flood the engine, causing the white smoke when you drive off.

Try idling for five minutes and see if it gets progressively worse. You may even kill the engine this way. Look for leaking fuel at the throttle shafts, where the overflow ends up after going thorough the float chamber vent tube, dumping gas down the carb throat.

Wed Jul 30, 2014 5:08 pm

I did replace the needle valve. But I drove this car for awhile after that with no smoke. But who knows what happens when you pull everything else apart. I'll put the old needle valve back in and see what happens.

The compression readings were:

#2: 120
#3: 120
#4: 100, then 115 with some oil

#1 has a spark plug insert that never stays in, so I didn't want to mess with it.

Wed Jul 30, 2014 5:09 pm

Yes, it does get worse the longer it idles for.

Wed Jul 30, 2014 8:43 pm

The og needle valve didn't make a difference. But the gas suggestion got me thinking more about the main jet. I changed it back to 120 and it's much better. No more smoke, and it's running better. Sounds better too. Less rumble and more fweem. Hopefully it stays that way. Thanks KTPhil!

But... when I got back from the test drive my battery was dead. It probably hasn't been charging for awhile but I haven't driven with headlights for a long time. Oh well, that's a job for another day. I'm happy to have made some progress on it today.

Sun Aug 03, 2014 8:26 am

Got it charging, easy fix. Just needed to polarize the generator. Anyway, I did have another instance of smoking. This time I was on the tollway driving 60-65 mph for about 10 min. Got off, stopped at a red light, and after about a minute started getting the same cloud. I've been reading about setting the float level, and am going to check to see if mine is right. But none of the posts say what the correct level is. I found an article that said 19.5 mm from the top, but it didn't say for what carb. Is that the right number for a 30 PICT 1?

Sun Aug 03, 2014 6:58 pm

Tons of smoke today, right back to where it was before. I checked the fuel level, it was about 16mm from the top. After more reading I found 12-14 as the recommended level. So, I added a washer to the needle (the other one was totally stuck to the valve) and had no change in the smoking. I also changed the oil after reading that extra gas dumping down the intake could get past the rings and thin the oil, causing the oil to then get past the rings and smoke some more (even after the cause was fixed). That also had no effect. I ordered a rebuilt carb from Volkzbitz. Even if the carb isn't my problem, it has some other issues anyway.

This is the most confusing issue I've tried to research. I can't even verify if it's gas or oil burning. If it is gas related, some say its a lean condition and some say rich. If the rebuilt carb doesn't change anything, I'm not sure what to try next. Heads? Get the original intake cleaned out and back on?

Sun Aug 03, 2014 7:28 pm

Potsie wrote: Tons of smoke today, right back to where it was before. I checked the fuel level, it was about 16mm from the top. After more reading I found 12-14 as the recommended level. So, I added a washer to the needle (the other one was totally stuck to the valve)

To raise the float level you should remove, not add, a washer.

Sun Aug 03, 2014 8:36 pm

Doh! Yeah you do. I guess I wasn't thinking there. But anyway, it's not too high. The level being too low would not cause the smoking, would it?

Thu Aug 07, 2014 11:07 am

Got my rebuilt carb from Volkzbitz and installed it today. Looks great and runs great, much better than the worn out one that was in there. But, it still smokes. So, that wasn't the problem but well worth the purchase. I'll keep working on it. I checked my fuel pressure recently, but it won't hurt to check it again.

If it was oil burning and not excess fuel, could it be because I changed the p&cs but didnt do anything with the heads? I'm wondering if the increased compression/vacuum is sucking oil past the valves.

Tue Aug 19, 2014 8:11 pm

Update: after more research I found that it was common for these engines to blow smoke while new piston rings are seating. Some said that could take 300-500 miles. I'm about 250 in now, and I think its almost gone. It doesn't smoke on startup anymore and only sometimes when idling. I'm keeping an eye on the oil level, but it's not burning much at all.

So, hopefully this was my problem, and it will just keep fixing itself.

Thu Aug 21, 2014 8:52 pm

KTPhil wrote: White smoke is gas, not oil....

No it is not! Fuel is black smoke...

Oil is more of a light grey, but definitely will smell of oil.

White smoke doesn't come out of air cooled motors, because it is water.

Thu Aug 21, 2014 9:41 pm

That's what I was always taught. White smoke is oil, black or dark gray is fuel. When I re-ringed my engine, I sandblasted the pistons, cleaned and honed the cylinders and had the heads redone using new exhaust valves. It didn't and has not smoked since the first start up. It's got about 600 miles on it so far. I used Grant piston rings, is it possible the rings are defective or one cracked upon installation?

Fri Aug 22, 2014 5:37 am

Yeah, it's definitely possible that one cracked or is defective. But the situation is improving. The last few times I've driven, I haven't noticed any clouds behind me. So, I'm leaning more towards the ring seating theory for now.

Tue Sep 23, 2014 6:26 pm

The smoke is totally gone now, so it must have been the rings.