As Dang suggests go back to what you changed first (points) and go from there. Otherwise you’ll go off track. Chokes look fine. Ed’s advice is solid.
rough running
- Thread starter nealf
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what does your spark plugs look like?
nealf
Well-Known Member
Haven't checked them yet. Will pull some today
THANKS for all the advice and if it warrants please keep it coming...
Neal.
THANKS for all the advice and if it warrants please keep it coming...
Neal.
Check to make sure they are not resistorized plugs. I'm still on the too-much resistance line of thought. We see this frequently over on 2002FAQ; folks put new plugs and wires on their car and if doesn't run well afterwards. Unwittingly, they buy resistor plugs and resistor wires, and maybe even a resistor rotor... each component adding more and more resistance in the system. The points are the weak link and they suffer premature failure because of the imbalanced system.
I'm not saying this is your problem, but if you find that you have those resistorized pieces, I'd swap them out for non-resistor parts.
Also... does your ignition system have a separate, ceramic ballast between the coil and distributor? Make sure that the wires/connections to that are clean and tight. Same goes for the connection to the condenser to the dizzy. The clamp holding that unit in place is the ground; it needs to be clean and tight.
Ed
The fact that you report the engine runs well when cold suggests (to me) that the problem does not lie with the integrity of your points. However, the screws fastening the points show "use," prompting the question, what gap setting are you employing and have you possibly measured dwell? (This is not to exclude possible coil or condenser issues from causing your symptoms.)
Since your distributor was designed to use two sets of points (primary and secondary, for maximum dwell), is it possible that by using only one points set - with your current setting - your dwell is inadequate to permit proper coil saturation? This might exacerbate a preexisting condition due to a weak or failing coil. Does the rotofaze maker recommend a gap setting for operating with only one (primary) set of points? This, as discussed later, may be a problem with igniting lean mixtures (rather than rich). This issue also begets ignition timing questions.
As you know, every time you set or reset your points you potentially alter your ignition timing. You mentioned in your first post "adjusting" the timing. Is this "by a couple of degrees," or "a big twist"? Are you using a timing light or other means to determine full advance?
The use of this atypical (performance) distributor leads one to suspect that other modifications were made toward achieving optimum engine performance. This might have included carburetor jetting, to ensure a leaner than normal mixture. If this is the case, ignition timing - including initial and total advance - becomes more critical - in your situation. When your engine is cold and presumably operating on a rich mixture, your present ad hoc timing setting may be wunderbar, but when the engine is warm and the mixture is leaned (without chokes) the ignition timing may be too far advanced to properly ignite that leaned fuel recipe. (Could leaving the chokes engaged be one impractical approach to the problem?)
Again, unless there is something defective with the original Bosch distributor it seems illogical that it could not work with your engine, as it was designed. While there is nothing inherently wrong with the aftermarket distributor, the (presumably) original Bosch version would seem (for the moment) to be more of “a known” than an unknown.
http://e9-driven.com/Public/Library/BMW-E9-Manual/pages/en/12110040.html
https://e9coupe.com/forum/threads/changing-contact-breaker-points-stock-ignition-3-0-csi.9514/
Unrelated
Interesting valve cover . . . among other things.
6 DeQ's or QTs?
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6 quarts
nealf
Well-Known Member
Lloyd I sent you a private message.
CookeD
Well-Known Member
Get your ignition sorted first, and then move on to fuel, and include checking for vacuum leaks. If running a point and switching your point made your car run worse, make sure your dwell is set correctly. If you have access to a dwell meter that is best (that's what I use), but you may be able to set the dwell with a multi-meter.
nealf
Well-Known Member
Ok I finally got a chance to work on my. At yesterday. And I made some progress. I broke out my timing light and tried to retune the distributor. I advanced the curve. It was WAY OFF?? I wonder if anyone can post photos of all the different timing marks on the flywheel. I know of the two which are pre and post dead center but there’s another one on mine I think and I have the light and the dizzy pointing to that round bump and the car actually runs MUCH better. This mark almost looks like one of those candy buttons that come in sheets for kids.
I thought that the correct mark was a silver ball. I didn’t see that while adjusting. I may need to get my wife to turn the dizzy while I look at the flywheel because I may have missed it.
So, can anyone post photos of the different marks for degrees on the flywheel? Thanks!
I was running points for years, then had to readjust every 3K miles or less. Car always had a stumble at 2800 rpm
Distributors are wearable parts and after 45-50 years, the curve changes. Advise buying a 123 Distributer, my 2800 rpm stumble stopped. Everything is so smooth now.
Distributors are wearable parts and after 45-50 years, the curve changes. Advise buying a 123 Distributer, my 2800 rpm stumble stopped. Everything is so smooth now.
There is one "ball" for TDC, it is the "TO" ball. There is another ball before TDC (rotating clockwise), it is the "Z" ball. Pull your plugs and rotate your engine until the knotch on the crank balancer lines up with the mark on the lower timiming chain cover. The distributor rotor should point to #1 spark plug. If it doesn't then rotate the engine once more. Once lined up look into the timing window, you should see a ball. This is the TO ball, paint it red. Rotate the engine again and 22 degrees before the TO ball appears the Z ball will appear. Paint this another color. Then with your timing light you'll know definitevely which is which. When setting the timing remember to adjust the RPM back to where it is supposed to be after turning the distributor. Repeat untill dialed in.
coupelady
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May I offer what happened to me while attending O'Fest? I do have triple side draft webers, I removed the inspection caps on the top of the carbs for detailing prior to the event. I thought I was super careful to replace the gasket properly then put back on each cap. It will burp and cough when cold but it continued during the trip to O'Fest, VERY disconcerting. Chris Ohmes got us together one night at O'Fest where I mentioned this situation. With his eagle eye he noticed that the rear carb cap was slightly cock eyed. SO yes I had not replaced the gasket properly. We also discussed the need to have the vent hole on the side of the carb blocked with a little sponge as I was told to do in the past by a trusted tech. We removed those. On my return home, I rejoiced over how well the coupe ran. It was a sincere pleasure to be driving this car. (Yeah, don't think those thoughts out loud as something will come up and ruin the experience). On my return home I sought the advise of a few technicians I think highly of. After many opinions and a call to a weber supplier, I was told that those vents should be left as is, no sponge. The channeling is not direct, you could throw a handful of sand at them, it would not enter the carb (these are 40 DCOE weber side draft configuration). I did order new gaskets for the caps which are now on the car. The 6 hour drive to Hilton Head SC last weekend for the concours was a true ultimate driving experience. A small thing like that can really change the balance.
Amy's beautiful coupe at O'Fest.
The inspection cover misfit will not cause your engine to run differently, they only cover the jets and are not air tight, the jets vent through the other hole you had sponge in. They could allow gas and fumes out though and this is what the gasket is for.
The sponges will cause your engine to run rich, and even more rich as dirt and gas fill them up and the atmospheric pressure between these and the main jets will also go out of balance. So when you removed them your air/fuel ratio came into a better zone and the engine ran better. If you want to run the filters then a rejetting to compensate is needed.
I disagree that no dirt can get in this chamber, idle jets do get plugged from dirt particles and since these jets are in play up until around 3k or so, there's a vacuum generated through the hole. Just put your finger over the hole at idle to see the rpm drop. Ideally they should be covered by an airbox along with the venturis but if not then leave them open and clean the jets occasionaly. I clean the residual gunk out of the fronts of these with q-tips when needed. I once saw a vintage Maserati with mini trumpets on these holes to match the main ones, how cool is that?
The sponges will cause your engine to run rich, and even more rich as dirt and gas fill them up and the atmospheric pressure between these and the main jets will also go out of balance. So when you removed them your air/fuel ratio came into a better zone and the engine ran better. If you want to run the filters then a rejetting to compensate is needed.
I disagree that no dirt can get in this chamber, idle jets do get plugged from dirt particles and since these jets are in play up until around 3k or so, there's a vacuum generated through the hole. Just put your finger over the hole at idle to see the rpm drop. Ideally they should be covered by an airbox along with the venturis but if not then leave them open and clean the jets occasionaly. I clean the residual gunk out of the fronts of these with q-tips when needed. I once saw a vintage Maserati with mini trumpets on these holes to match the main ones, how cool is that?
or you could put miniature velocity stacks on them like this Maserati...
Steve sent me that pic years ago...
Yes that's it!!
nealf
Well-Known Member
I just did another shakedown test drive multiple starts and stops. I must say the car is running real well. Idle a bit high but I am afraid to mess with the dizzy advance again. I do have that aftermarket mechanical advance dizzy so maybe the engine is set up to run more advanced? I hear no pinging while under load and no popping or unburned fuel explosion going down large hills.
If idle is too high, it may diesel when shutting down. It should be at 950rpm.
nealf
Well-Known Member
It didn’t diesel at all and I may just keep this setting until the run quality denigrates.