Black-grey smoke out of flame arrestor?

C

C. Trembanis

Member III
What does it mean when black-grey smoke belches out from the flame arrestor.
I have been experiencing a loss of power in gear. Just as the motor dies the smoke belches out. Cloged intake manifold (plenum)? I've cleaned out the carburetor. Not installed as yet. Problem started when the PVC (indigo) was installed. New gas filters (primary and secondary). Anyone with any ideas.
Thanks, Chris
 
CaptDan

CaptDan

Member III
C. Trembanis said:
What does it mean when black-grey smoke belches out from the flame arrestor.
I have been experiencing a loss of power in gear. Just as the motor dies the smoke belches out. Cloged intake manifold (plenum)? I've cleaned out the carburetor. Not installed as yet. Problem started when the PVC (indigo) was installed. New gas filters (primary and secondary). Anyone with any ideas.
Thanks, Chris
Click to expand...

What's the 'PVC' - electronic ignition? The blowback in the carb suggests faulty ignition. Could also be overly rich mixture, or both. Have you checked the plugs? Are they black and/or moist?

How did the engine behave before the 'PVC' was installed?

Capt Dan G>E35II "Kunu"
 
Cory B

Cory B

Sustaining Member
Check your timing. Make sure you didn't cross any sparkplug wires. Could be a valve issue.

Also, I was not a fan of the Indigo PVC back when I had an A4. I tried it for a while then ripped it off. IMHO if you've got blowby thats so bad you can't live with it, its may be time to rebuild. I'd suggest taking it off and see if the problem goes away.

If you haven't already, get Don Moyers A4 book at http://www.moyermarine.com. I still miss our old A4.
 
C

C. Trembanis

Member III
CaptDan said:
What's the 'PVC' - electronic ignition? The blowback in the carb suggests faulty ignition. Could also be overly rich mixture, or both. Have you checked the plugs? Are they black and/or moist?

How did the engine behave before the 'PVC' was installed?

Capt Dan G>E35II "Kunu"
Click to expand...

Engine ran very well before the PVC was installed. (blowby indigo product)
New spark plugs and wires. Plugs are now black after just idling.
Compression check has all 4 clys at 105lbs of pressure. (dry testing)
Also pentronix electric ignition. Idling good to full range 3000rpm however when put in gear sputters, rpms go up and down and eventualy dies then the black smoke.
Chris
 
CaptDan

CaptDan

Member III
My personal opinion: if it works, don't fix it.

I've owned and maintained A4s since 1991. I've never bit the bullet and gone with an electronic ignition because the old mechanical units are reliable and easy to maintain - IF they're kept clean and dry. Setting and adjusting point gap is one of the simplest maintenance tasks to do, and decent points might last up to 200 hours before they need replacement - a $20 proposition including condenser.

I hate to tell you to switch back to the old unit after having paid for a PVC. It could be something as simple as switched wires, as already said. Or - it could be a faulty unit. First, be sure the distributor cap wires are in proper sequence - and if the distributor was removed for the E-ignition install - that it's oriented in the right timing position. Then run the engine under load. If the problem persists, I'd reinstall the old unit with a fresh set of points and call it a day.

Certainly, an electronic unit is more precise, might save you a few pints of gas, makes the engine run slightly smoother and MAYBE easier starting. On the otherhand, if it craps out underway, you're SOL unless you have a backup.

I'm not a Luddite, but this is one item that strikes me as a problem waiting to happen.

YMMV.

Capt Dan G>E35II "Kunu"
 
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Randy Rutledge

Randy Rutledge

Sustaining Member
Have you checked the ignition timing and made sure there are no crossed plug wires? If the timing is set high it could cause the engine to kick back when the rpm lowers on a stall.

Check the exhaust where the water injects in the hot pipe, a restricted exhaust could cause this problem. The smoke from kickback is not worn rings it is a result of a cylinder firing while the intake valve is open.

Do you run miracle oil in your gas and in the oil? That is recommended for the A4 as there is a tendency to have sticking valves on any flat head engine since the oil runs off the valve instead of down the stem into the guide.. I replaced the valve springs with the heavier ones from Moyer Marine on my A4.
 
tenders

tenders

Innocent Bystander
PVC isn't electronic ignition, it might be a typo for "PCV," a shortcut for the "pollution control valve" that car engines use -- an Indigo product that puts a vacuum across the A4 oil sump to draw blowby fumes into the intake rather than have them vent into the cabin.

My guesses to the solution to this problem are:
(1) a severe timing issue -- crossed wires or misoriented distributor (not an electronic/analog ignition issue)
(2) that the main jet and idle mix need to be tweaked a bit because the PCV spacer changes the fuel/air mixture a bit.
(3) valve stuck open.

The electronic ignition module isn't much of a suspect to me in this. Either it works flawlessly or it doesn't work at all.

I was a holdout against electronic ignition but I'm a convert now. Of course if you're careless messing around with the electricals on your engine, you can cause it to fail, but has anyone heard a single case of A4 electronic ignition crapping out underway? It's no trouble keeping the analog system on board in a plastic bag with some silica packets for emergency use...and there's a reason they don't install analog ignition systems in cars these days.
 
Cory B

Cory B

Sustaining Member
Quick clarification, our PCV valve quickly got "clogged" by the blowby gases it was supposed to reduce. The old breather tube is impossible to clog. We also went with the pertronix ignition, and kept the old points in ziploc bag like Tenders did. We felt it was a worthwhile upgrade - never needed adjustment, very reliable, and easier starting. Even though I could rebuild the engine and write complex web-based database applications, for some reason I could never get points ajusted correctly.

It really sounds like a timing and/or mixed up wire issue. With no load the A4s can run seemingly fine on just two cylinders. You can even limp into dock with just 2 cylinders. :)
 
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ChrisS

ChrisS

Member III
Just went to electronic ignition

After some rough running, we just switched over to the Petronix system, and the engine now runs like a top. The danger to the electronic ignition is leaving the ignition on, which heats up the unit and can toast it--so I keep the key in the off position when it's not running.


As it turns out, a plug was wet and the A-4 was running on three cylinders (it was running fairly smooth, but just low-powered, with some smoke when it was cold). The engine was running rich and the points were worn, so check the timing and the carb.

The Moyer site has lots of info to help you troubleshoot, and to get to know your engine. Don will answer any question you post to his forum--it's a great resource.
 
CaptDan

CaptDan

Member III
tenders said:
PVC isn't electronic ignition, it might be a typo ...and there's a reason they don't install analog ignition systems in cars these days.
Click to expand...

You bet. It's called 'Non-Owner-Maintenance.:) Of course, if you want to invest in the appropriate digital readers and proprietary tuning gear, no problemo. ;)

But you have a 'point,' - an electronic ignition is likely more trouble free and smoother running.

I just feel more comfortable with the old stuff.

Capt Dan G>E35II "Kunu"
 
E

Emerald

Moderator
I'm with you Dan. I'll take the system I can put in my pocket and rebuild for $15 in spare parts (condenser and points) after spending 10 minutes trouble shooting. Electronic ignition is great until it breaks, and I realize for the average joe that is good enough. Just dumped the 2002 Audi for a '67 Alfa, and being able to work on it without a #@#! computer in the middle (which is what I do for a living!) was a big big plus in the equation. Yeah, maybe the Webers and old mechanical Bosh distributor won't idle as smoothly, but I can count the thousands of $ the dealer won't be getting and Emerald will :egrin:
 
tenders

tenders

Innocent Bystander
> just for nomenclature's sake, it actually stands for Positive Crankcase Ventilation

Oh, yeah! I knew that when I replaced one on my car a long time ago. Somehow I forgot it. How does that happen?

Prices for a new set of points and condenser are about 1/3 the cost of the Pertronix electronic ignition kit. Still haven't found anybody who got themselves marooned with electronic ignition!
 
Randy Rutledge

Randy Rutledge

Sustaining Member
I am just stingy. I do the point adjustment by sight and the timing by listening to the engine while moving the timing and then if she cranks OK I am done. I have been doing that on engines since early 60s and the process still works. I have the tach-dwell meter and timing light but have hardly ever use them. Has anyone ever filed an electronic ignition and fixed it?

Electronics are very stable. That means they work when they work and that means when they quit they have quit.
 
CaptDan

CaptDan

Member III
Emerald said:
Electronic ignition is great until it breaks, and I realize for the average joe that is good enough. Just dumped the 2002 Audi for a '67 Alfa, and being able to work on it without a #@#! computer in the middle (which is what I do for a living!) was a big big plus in the equation. Yeah, maybe the Webers and old mechanical Bosh distributor won't idle as smoothly, but I can count the thousands of $ the dealer won't be getting and Emerald will :egrin:
Click to expand...

I hear ya, David. Seems there's no free lunch in the world of hi-tech.:rolleyes:

To answer the question of whether I've heard of anyone marooned because of a faulty electronic ignition: no, not personally. However, I know somebody quite well whose A4 quit because of a stuck needle valve. :egrin:

Capt Dan G>E35II "Kunu"
 
Randy Rutledge

Randy Rutledge

Sustaining Member
My A4 quit three times during my fun at the Dauphin Island race weekend. Twice with a restricted needle valve and once with a blocked needle that caused flooding.

I rebuilt the fuel system this winter but cut a couple of the heavy ¼” fuel lines with a saw (BAD idea) and the fuel pump must have had trash in it. The fuel tank was scrubbed clean inside and all associated tubing and fuel lines were replaced as was the water separator/fuel filter. There were chips of the rubber in the carb from where I had used a saw causing the problem.

The nice thing about the carb on an A4 it takes about 10 min to remove clean and replace, or have I had more practice than the average bear. An inline just before the carb and all is well and no more saw on rubber fuel lines.
 
R

rwthomas1

Sustaining Partner
I'm a bit of a Luddite to a point but this may be pushing it a bit.....

I used to build drag racing engines and have worked on many, many engines. With the exception of the Concours restoration crowd and the diehard retro guys that like messng with magneto setups, electronic ignition is the only way to go. Now I don't own an A4, nor do I plan to, however I do know that an electronic ignition will provide a hotter spark of longer duration and more stable timing. Simply put, the engine will run better. Pertronix setups are cheap, the classic car crowd uses them too. A spare Pertronix or just hanging onto the points setup is a quick and easy solution if you think the electronics are going to fail. You are far more likely to have a set of points fail or have another engine related issue DUE TO POOR RUNNING FROM THE POINTS, than the Pertronix failing. Carboned rings, fouled plugs, etc. Some things are better left in the past and points are one of them. GM went electronic in 1974. Your lawnmower has been electronic for years. RT
 
CaptDan

CaptDan

Member III
The most vulnerable aspect of a gas engine in a boat is the ignition, IMO.
Moisture on ignition parts is a prime reason for engine malfunction, and I'm willing to bet that most of the horror stories about A4s derive from boats with leaky cockpits and the engines situated directly beneath. In fact, been there - done that.

In that type of situation an electronic igntion would be more reliable - assuming the rest of the ignition components (plugs, wires, etc) can be kept moisture free. However boats with engine boxes placed well inboard - such as those on certain models of E35II - are far less vulnerable in this regard, and owners such as myself might find either type of ignition reliable.

It's definately true - faulty ignitions launch a chain reaction of malfunction, leading to fouled plugs, sluggish performance and spark failure. If engine accessibility is a problem, and periodic points maintenance an issue, then an ss ignition is the way to go.

That said, I'm not likely to abandon me olde Delco mechanical system any time soon. :nerd:

Capt Dan G>E35II "Kunu"
 
E

Emerald

Moderator
Hi,

I can't disagree from a technical standpoint on all the good things about electronic ignition and why it is better, and on something like my old Nortons, the points came right off and I always went electronic. On the 4 banger Alfa or V12 Ferrari, I'm a lover of MSD units and the old points, but I guess I'm a glutton for punishment since I've got 4 sets of points on the V12 and know many happy drivers who converted their V12 long ago, my father being one of them. Of course, putting the MSD on is kinda stratling both worlds. But to get back to the A4, I might take this approach. If the ignition system is in need of work, upgrade it to electronic ignition. If it is OK and using points, then leave it alone - if it ain't broke, don't fix it. I do have a bad taste in my mouth from being left dead on the side of a highway in the winter in the middle of the night from electronic ignition failing due to about 2 ohms of resistance in a ground wire. I acknowledge that the spring etc. could have broken on points and left me just as disabled, but I still figure I could have trouble shot the points on the shoulder of the road with less effort and fewer tools. I think some of this just gets to personal bias, experience and comfort levels and is actually a plot by the beer vendors to give topic for gear heads to have something to chew on late Saturday afternoons :egrin:
 
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