Rough running / stalling - Could it be the coil?

[Bonnyboy]

Yesterday I took an early morning drive down to the cabin top down.  40 minutes mostly on highways cruising at highway speeds (up to 90 mph in a few spots).   Stars were out and the heater was cranked.  It was bliss.  After 5 hours of sanding, painting, cleaning, mowing, using the chainsaw, sweeping etc.  I decided to get back home. 

Car had trouble starting and wouldn't run very well and really would not idle.   I just needed to get home so after making it through the border by blipping the throttle I got back on the highway where it ran fine at higher revs.   5 miles from home I got stuck in a 1 1/2 hour traffic jam right at a bridge I had to get over.   Anyways I did make it home after numerous stalls and slowing down with parking brake with clutch in and other foot blipping the throttle.

Once home I waited an hour and the car and tried to start it and it would just turnover and not fire.  After going through the archives last evening I think it may be the coil - I had this problem intermittently all summer but thought I fixed it with new plugs.    Car works fine when real cold but not once warmed up.


I called the Mercedes shop and they said the part number for the coil is 000-158-2803 (blue one).  I asked for the red coil and they said that it isn't for my car but they could get one if I really want it 000-158-4903.   

I will pull my coil to see what was in there  - is there anything I should look for to see what coil is the correct one to use?   The one in the car is at least 28 yrs old so maybe time to replace it anyways.
 

[ja17]

Be aware that the ignition is different if you have the standard ignition or the factory electronic ignition. Parts should not be interchanged between the two.

[Bonnyboy]

Thanks,   my car was built in 1969 but seems to be a 1970 model. It has points and based on my research I think it should have a "black coil" but the Mercedes shop insisted that I need coil number (Bosch)W0133 - 1616454 / 0221-122-001   (Mercedes) 000-158-2803    I told the Mercedes shop I have points and they said that my coil would be the number they gave.         

I will look for relays under the battery tray but if I have points I didn't think there could be an electronic ignition.  Am I missing something here??  Do I have the wrong coil number?

What would happen if I put the wrong coil on there.  I am not interested in installing an electronic ignition until I figure out what is causing my problems.

I haven't had a chance to play with the car yet but will be checking the cold start valve and the points next week when I am off.  I'll also see if my plugs are fouled again?

[Tyler S]

All cars had points regardless of if they had electronic ignition. The difference being in a transistorized system the transistor box actually fired the coil and the points were just a trigger signal.
Putting the wrong coil in- a transistorized system will cause low spark output.
Putting a coil from a transistorized system into a conventional points car will fry the points in short order. You also need to make sure the correct ballast resistor is installed on the left fender well.

[Bonnyboy]

Thanks all.  This gets more confusing as I go.

I uncovered the numbers on the old coil in the car - 0.221.102.036   KW 12V
This number doesn't seem to correspond with anything except a Mercedes 6.3 engine

I will wait until next week to call Bosch to see if they have a cross reference and if it is anything close to a Black Coil (0.221.119.021) in a different guise and see why the Mercedes dealer is trying to sell me a Blue Coil (0.221.122.001) 

I checked with the local parts supplier and they said that the Bosch number cross references to a AC Delco U505 which seems to have lots of applications including big block Chevys.

Thanks all.  I will report back.

Merry Christmas all and may your santa bring you what you need and possibly if you are real good - what you want.


I went under my car this morning and I have no resistors, transistors, boxes under the battery - just a clean battery box tray.  I have a single ballast resistor on the sidewall of the engine bay. 

 

[Tyler S]

That AC Delco U505 is what my dad put in his/my car way back when about 20 years ago. It worked just fine but not original. The ballast resistor bracket should have a resistance number stamped on it (0.9, 1.8, etc.)next to the mounting holes.  This will tell you what coil should be paired with it. A "red" coil requires the 1.8 ohm ballast resistor be installed. Keep in mind the "red" coil is actually no longer painted red. Its case is silver with red/orange labels. X referencing using the bosch numbers is much easier as the mercedes numbers have changed multiple times. 
000-158-28-03= for transistorized ignition only
000-158-49-03= red coil, requires 1.8 ohm ballast resistor

[Naj ✝︎]

I uncovered the numbers on the old coil in the car - 0.221.102.036   KW 12V


 

This is a version of the old black coil, NLA from Bosch

Should now use the 'red' coil with a 1.8 ohm ballast resistor

https://www.sl113.org/wiki/Electrical/IgnitionCoil

naj

[Bonnyboy]

The plot thickens

I spent a couple hours pouring over my repair manuals and this site and decided to start checking things  - got the multi meter out and thought I had better look under the battery tray and around that area one last time before I was sure there were no special boxes.

As I was looking up at the distributor I notice that the housing for the vacuum advance was not tight to the distributor case.   Ahah - missing a bolt and the advance would be off. 

So I marker the distributor (but actually marked the housing so didn't actually mark the position) pulled the distributor out after putting in a new screw for the vacuum advance I put it back as close as I thought it was. It seems off  bit based on the tension of the wirres now.

Checked the timing at 800 rpm and I set it to about 10-12 degrees as that is as far as I could turn the distributor without it stumbling.  At 3,000 rpm it is about 25 degrees.   ( this doesn't seem right)  I could only see one set of timing market for the triangle shaped marker.  I reconnected the vacuum line and thought I was done.

The car was running nicely in my shop so I decided to take it out for a spin.     I got 1/2 block and it started to falter and had no power under throttle and I barely made it home - it kept on stalling     I popped the hood and and the car stalled - after a couple minutes with the ingition on,  fuel started coming out of the filter on the fuel injection unit.  I shut it down and then tried to start and it didn't.   

questions - should I start over with a static timing with cylinder 1 at TDC? and then go from there
Is the fuel coming out of the filter on the injection unit a sign of something?

Help...



 

[Tyler S]

If you have fuel coming out of the filter on the injection pump, you have bigger worries right now than timing. Make sure the cold start valve hasnt become stuck open for some reason. That can/ will push fuel down the air pipe and back out the filter. Try isolating that issue first. If it is coming from the injection pump side of things then make sure your return line isnt blocked. If these check out then there is an internal issue with the IP. Also pull your engine oil dipstick and be sure the crankcase isnt full of fuel.

[Bonnyboy]

Remember. gasoline is flammable - be careful out there........ !!   I use Chevron 94 Octane with no alcohol so I consider this gasoline.


I checked my dipstick and the oil appears not contaminated with gasoline - I will change just in case.

I took the cold start valve assembly off the manifold and cranked over the car to see what the spray pattern was like and I got lots of fuel and a loud pop and a nice sized fire all the way down the inside of the engine compartment.  Not wanting to make a mess with the fire extinguisher I just blew it out, and blew and blew.  My eyebrows are still intact.   Now I see why the checking the orifices was done inside a clear plastic bag.

I disassembled the cold start valve assembly and my valve was different than shown - it was a sealed unit that looks like a typical check valve.   I had enough air left and lots of adrenalin by this point and was able to blow through it,  so after cleaning with alcohol brake cleaner, soaking it for the morning and more cleaner and WD-40 and spinning the ball inside with a chop stick she doesn't leak anymore. 

I put it all back together and car started and set into a fast idle

No fuel came out of the filter on the injector pump and it sucked air until it warmed up and then the idle dropped a bit.

Now to set the timing - I'll start with static timing because I probably messed it up taking the distributor out to fix the vacuum advance.     

[Bonnyboy]

Success.   Thanks all for the helpful hints.

The cold start valve appears to be working fine now.
I set the timing  -  static first then fine tuned with a timing light.   38 degrees at 3,000 rpm which gave me approx  8 degrees at idle.

I shoveled a bit of snow to get out of the garage and went for a brisk ride - car runs like a different car - it pulls harder now over 4,000 rpm right on up.   Once I got to the highway I pulled out to pass a car and floored it.   I wasn't expecting that big of a difference - 170 k/ph came up pretty quick

Car idles fine, starts fine warm and cold so I consider this a success.

To recap - my electrical issue that I though was a coil turned out to be:
1.  the advance housing on the distributor lost a bolt and was in perpetual advance
2. the cold start valve was stuck open and was spewing fuel into the intake etc. 

Now to sell the coil I bought.

Thanks again everyone for the help - especially Tyler - you hit my problem it on the head

[kampala]

Great to read a success and especially for recapping the solution.   That fire sounds pretty scary.   A good reminder.