White Smoke
Thread Starter
8th Gear
Joined: Mar 2017
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White Smoke
Replaced plug, plug wires, & fuel filter in my 71 Stingray. Did not touch the timing or carb adjustments. Now have a miss & white smoke out the exhaust when running, but it does run & idle rough. What did I do?
Race Director
Joined: Oct 2008
Posts: 19,172
Likes: 1,668
From: Long Island
crossed wires or a cracked plug.
Pull the wires in firing order and use an OHM METER to be sure you have the ends of the same wire.
Put one test end of the meter on each wire end and confirm it's the same wire.
Using a WINDEX bottle spray water on the plugs in a darkened area and look for sparks on the plugs. Sparks = cracked plug or bad wire.
Lastly be sure you did not move the wires one terminal on the cap, - check the timing.
Instructor
Joined: Nov 2014
Posts: 161
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From: Georgia
If it's white smoke ( not steam ) and it's an automatic, check the vacuum line at the carb that connects to the modulator valve on the transmission . If it has transmission fluid inside ,then the modulator diaphragm has a leak allowing transmission fluid to be ingested by the engine causing white smoke. The tune up may be just coincidental.
Safety Car
Joined: Apr 2006
Posts: 4,057
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From: BC
If the plug wires are not crossed did you drop or knock one of the plugs against something when installing them? You might have lost the gap creating a miss. As said above, check your plug wires for the proper firing order.
Last edited by CanadaGrant; Mar 21, 2017 at 11:09 PM.
Thread Starter
8th Gear
Joined: Mar 2017
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White Smoke
Thanks for all the responses. I do have another question. Originally the car had R44 AC Delco plugs gapped @ .035. When I installed the headers I had to use a shorter plug in a couple of the cylinders. Since I have MSD pointless ignition I installed NGK plugs w/.045 gap. Could that have caused the problem? 1971 car w/1980 re-built 350.
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Drifting
Joined: Aug 2009
Posts: 1,346
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From: new iberia la
If its puffing white smoke, you likely have a head gasket leaking coolant , which will cause the cylinder its leaking into, to misfire .... crossing wires ,or wrong or improperly gapped plug will not cause white smoke
Team Owner
Joined: Jan 2006
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From: Crossville TN
If you didn't change the ignition coil when you added the MSD box, .045" gap is too large. Your coil will be drawing to much current OR you will have spark 'miss' condition.
But, I think you have swapped two plug wires by mistake. Recheck the plug firing order: 18436572
But, I think you have swapped two plug wires by mistake. Recheck the plug firing order: 18436572
Thread Starter
8th Gear
Joined: Mar 2017
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White Smoke
The whole ignition is MSD. Distributor, coil, & box. I bought it that way & have not changed anything except for plugs, wires, & fuel filter. Have tried to move wires, but then the car will not start. I read somewhere that Bubba could have wired this thing funky. What do you think?
Is my vette stock?? HAHA
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Pull one wire at a time and you'll find the bad cylinder because the idle won't change. Pull that plug and see what's up with it.
Is the MSD unit New or used
Is the MSD unit New or used
Thread Starter
8th Gear
Joined: Mar 2017
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White Smoke
Ignition system is @ least 5 years old. I bought it 5 years ago & motor had less than 10,000 miles on re-build. Should have took a picture of position of wires & distributor cap prior to removing wires. But again, this is only way motor will start & run.
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
"Guessing" which wires go where is not a viable way to check out firing order. If you can't check the firing sequence by going around the distributor cap wire-by-wire we can't assist you.
Racer
Joined: Jun 2016
Posts: 336
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From: Il.
Get the timing mark on the balancer at TDC and remove the distributor cap if it's close to no 1 on you're cap than it's on TDC if it's on the opposite side you need to spin the engine to the next time the timing mark is at TDC you can spin the engine with a socket and a 1/2 in ratchet,clockwise, on the balancer bolt.Than line up the no 1 plug wire on the cap as close as you can to the rotor on the dis.The distributor turns clockwise so if the #1 on the cap is counter clockwise of the rotor it will be advanced if it's clockwise of the rotor it will be retarded so move the distributor so the rotor and the #1 plug are lined up ,if anything make sure it's slightly advanced . Get a timing light ready to go and try starting it should start but may not run very good than get on the light and adjust the timing to what ever the engine calls for in the book.
I agree it probably is not you're timing white smoke is mostly caused by ether trans fluid or anti freeze as the above have said .
I agree it probably is not you're timing white smoke is mostly caused by ether trans fluid or anti freeze as the above have said .
Last edited by sparky77; Mar 22, 2017 at 06:35 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
If your plug wires are routed in the 'factory' manner and you can't easily tell which wire is which, you can remove both ends and use an ohmmeter to determine if those are ends of the same wire...or not. Do one wire at a time, or you may get totally lost in the process.
Wish you luck.
Wish you luck.