Engine cut out while driving

Drew Gregg

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I'm getting the car ready for the 650-mile trip to the Highlands Motoring Festival in North Carolina, June 8-11. BMW is the featured Marque with 15 of the 85 cars invited to the event.
The engine needed cleaning so I attached a low-pressure nozzle to the hose and cleaned the typical dirt & grease off the carbs and engine block. I tried to not get the 123 Distr. and coil wet.
20 minutes of hose and 1 hour of compressed air & towels and the engine compartment was dry looking.
The car started up as usual. The next morning,I drove 15 miles up to 80 MPH to a C&C. Two hours later, driving 50-60 MPH after 10 miles the engine stropped. Then a few minutes later the engine started and I drove about 100 yards and the engine stopped again. I opened the hood, and checked the wires at the coil. All was correct and the coil was not even warm. The engine started and I drove the car to a gas station and waited in the Costco line 10 min. with the engine idling as usual. The car ran fine for the 5 miles home.
The red Bosch coil was replaced with a black MSD coil about a week ago and this was the first time the car was run on the road with the new coil.
I asked my mechanic to check the ground wire on the coil back to the fuse block. All was fine. The inside of the Distr. cap was dry.
Any thoughts on what might have caused the engine to stop twice and then run like nothing happened?
 

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HB Chris

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Ground wire to fuse block? Green wire to positive terminal, black wires from negative terminal to tach and dizzy.
 

Drew Gregg

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Sounds like the last vestiges of moisture working itself out. Or your engine doesn't like your new coil. I'd physically dry the dist cap again. And take your old coil with you to NC :cool:
The cap was inspected and the Bosch coil is going with me.--good advice!
 

skk

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I taught myself not to spray water at engines for the same reason many years ago. Now you have an unknown, intermittant
water-related flaw, likely electrical. You might get a hair dryer (or a sturdier, not-my-wife's, hotter heat gun from harbor freight)
and lightly toast up the surface areas of the carbs, wires, plugs, distributor, coil, junctions etc. making sure to not melt a hose,
cause a gas fire, or melt any insulation.

Keep the blower moving always.

Also good to have some fine abrasive paper for metal, remove connectors 1 at a time, make contacts shine, reassemble, and use light electrical contact protectant.

Sometimes when you remove a connector, the wire craps out and falls apart in your hand, consider that good luck! It didn't happen
on the highway.
 

Arde

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I did steam cleaning a couple of times in search of where an oil leak was coming. No problems. Perhaps evaporation happens faster with steam vs water…
 

tferrer

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If I clean and engine I start and finish with spray bottles. First cleaner (PS21 diluted a bit) and then brush to loosen then rinse with a spray bottle of water
 

lip277

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Over the 45 years of messing around with cars - I have washed engines many many times. Vast majority turned out fine - no issues.
But, I have also had a couple of instances where the motor ran rough or sputtered for a time after I did my cleaning. I never had one outright stop running though.
When I did have issues, I never really had to find out what was going on. Letting the car sit overnight or out with the hood open let the moisture resolve itself and it ran great shortly thereafter.

That being said - I have never used high pressure water or such for this activity (just out of the end of an open hose - no nozzle or jet action).
Compressed air is also an issue IMO - just as water under pressure itself can get it into areas that you don't want it to - using compressed air can do the same. Sure, most of the water will fly away - but there is a chance that some of the water could be pushed into areas that are not friendly....
If you want to use air - use a leaf blower or such... not high pressure air.

My nickel anyway.
YMMV
Good luck
 

mulberryworks

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spray some contact cleaner (or wd-40 in a pinch) inside your distributor cap to dry it out.
WD-40 stands for Water Dispersion, 40th formula.
"The spray, composed of various hydrocarbons, was originally designed to be used by Convair to protect the outer skin of the Atlas missile from rust and corrosion."

It does work for cleaning out distributor caps, but I think I'd also prefer contact cleaner. Use gloves though, it's a power degreaser you don't want on your skin.
 

HB Chris

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Sounds like an overheated coil. Where is your ballast resistor? Red Bosch coil needs 1.8 ohm resistor, coil only wants 9 volts, not 12. Does the MSD coil have a spec on the label? The original Bosch black coil use 0.9 ohm resistor. If running Pertronix it gets 12v from the green power on the ballast BEFORE the resistor.
 

Stevehose

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Sounds like an overheated coil. Where is your ballast resistor? Red Bosch coil needs 1.8 ohm resistor, coil only wants 9 volts, not 12. Does the MSD coil have a spec on the label? The original Bosch black coil use 0.9 ohm resistor. If running Pertronix it gets 12v from the green power on the ballast BEFORE the resistor.
He's running a 123 so he doesn't need a ballast resistor (they recommend a red Bosch and no ballast), which I always thought saved the points, not the coil. I haven't run a ballast resistor in years since installing the 123.
 

Drew Gregg

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To reply to the last few posts: Kevin @lip277: I have also used a hose to clean engines in cars & trucks I have owned for many years with the same results you have mentioned. I think the compressed air to dry off the entire engine compartment probably got moisture in an electrical part. The weird thing is the engine ran the next day for 15 miles before the mishap and then started up as though nothing had happened.
Chris @HBChris : The coil was the first thing I touched and it was not hot at all. I just ran a 20-mile test run this morning and the black coil is now hot to the touch. But the entire engine is hot also and the coil is above the Stahl header that has no heat shield. That's how the engine has been for the past 3 years. The restoration shop put the shield under the header. (I guess those award-winning Ferarri's they brag about have heat that doesn't rise).
Steve is correct about the red Bosch coil/123 distr./no ballast resistor. That's how the engine was set up 3 years ago. I had never touched the Bosch coil after a morning drive. @Stevehose,do you recall if the red coil is hot to the touch? Thanks for all of the advice.
The car ran fine this morning for 20 miles of high-speed driving to duplicate what I'll be doing for 14 hours in 2 days next week on my trip to Highlands, NC.
 

Stevehose

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do you recall if the red coil is hot to the touch?
no, I can't say that I ever noticed, seems it gets just as hot from ambient temp as anything else under the hood. Your coil located by the fresh air hole should keep it as moderate temp if not more so than any other location while in motion. Might be a while before I can check mine for you :D
 

Luis A.

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If your MSD "Black Coil" is a Blaster 2 the primary impedance is too low for the 123 at 0.7 Ohms. 123 distributor calls for a primary of 1.0 Ohms or greater. There is a risk now that the output stage of the 123 may be damaged by driving such a low impedance.
 

Drew Gregg

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If your MSD "Black Coil" is a Blaster 2 the primary impedance is too low for the 123 at 0.7 Ohms. 123 distributor calls for a primary of 1.0 Ohms or greater. There is a risk now that the output stage of the 123 may be damaged by driving such a low impedance.
Luis--You are absolutely correct! The MSD Black Blaster 2 coil is the one I put in the ignition circuit. While driving to Highlands, NC from Ft Lauderdale, (760 miles), I noticed random misses in the engine at all sorts of speeds while on the Interstate. I then read your post on my phone and switched back to the 123 preferred Bosch Red coil before the 110-mile tour of the mountains. That drive used all 5 gears and the miss was gone. The Interstate drive back home was also w/o any misses at speeds from 30 to 95 MPH.
Thanks for the advice!! The MSD coil is probably good for any ignition circuit other than the 123 Dizzy. Should the ballast resistor be used with the Blaster 2 MSD coil? Drew
 

Luis A.

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Should the ballast resistor be used with the Blaster 2 MSD coil? Drew

You'd need to use a ballast resistor of such value that takes you to somewhere above 1.0 Ohms. The 1.8 ballast resistor normally used with the red coil will bring the primary impedance to 2.5 which will work but greatly diminish the current and therefore the induced spark voltage.

Bosch makes both a 0.4 and 0.9 Ohm ballast resistors. Blue and silver bands, respectively. 0.4 is too close to 1 Ohm for my taste so I'd go with 0.9 bringing you to 1.6 Ohm which is right around the Bosch "red coil" primary resistance. This is one of the options we will have to use going forward as Bosch no longer makes the "red coil" PN 0221119030.

123 USA and 123 NL are selling no-brand coils that are black in color that are 1.5 Ohm in primary impedance but no other specs are given. I'd be inclined to use the MSD or another high inductance (8mH) coil with a .9 Ohm ballast.

EDIT: 123 NL confirmed their black "red coil" is actually 2.1 ohms in primary resistance.
 
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