CSi suddenly dies

[BMW3.0CSi]

Hi,
- if the engine had run for 200km, then the overall system was working initially properly and something has died/changed after 200km.
- I do not understand the current status:
- is the starter still much to slow ? and/or
- is there an ignition spark ?
... a lot of success

The starter was and is working fine after the car cooled down for 1.5/2 hours after it happend. When the tow company brought me back home the car already started. 2 weeks later when I went for a 2 km ride to the gas station it also started and run like normal, starting and driving went like normal. But just after the incident happend the starter motor didn't want to work like normal, it went around very very slowly.

I will do some reading of the electrical system to get a better understanding of what might happened and how the different parts are connected to each other because that's not fully clear for me.

 

[wilies13]

OK. What I got now is, that
- the car starts normally "cold"
- engine stops to work after some time

There could be really a lot of topics. A first step would be to identify if it is in the electrical system or in gasoline supply/injection system.
One simple approach would be to install such a thing:

You would start a test trip with installed tester and when the engine stops you can easily check: Does the whole ignition system still working ?

 

[Wladek]

Thank you Wladek! So it's at least a CSi distributor. Is also see that's the ones on your pictures have the smaller advanced ignition bulb. The ones that Keshav mentioned have a bigger one, but that's something different.

CSI D-jet just have smaller than others.

 

[BMW3.0CSi]

OK. What I got now is, that
- the car starts normally "cold"
- engine stops to work after some time

There could be really a lot of topics. A first step would be to identify if it is in the electrical system or in gasoline supply/injection system.
One simple approach would be to install such a thing:

You would start a test trip with installed tester and when the engine stops you can easily check: Does the whole ignition system still working ?

Your statement is correct, but main suspect is the ignition because I had a few back fires when the car stopped during driving. Which to my opinion means that the injection part kept on running and still received signals to inject fuel. The back fires were really loud so there was more then enough fuel. I recently also placed a post on the injectors which also had issues, but the injection part is as good as completely new, besides the wiring harness.

I will try to figure out if I can find something to monitor the ignition system like you are suggesting, or real time if possible.

 

[wilies13]

Hmm...the back fires are an important info; current I have not really an idea how to interpret...
Due to the failure is not the whole time...
- could be a thermal problem. Ignition coils have it sometimes.
- could be an electrical contact. Even in injection system.
Recently I had sporadic ignition problems due to only a little loose contact on ignition coil ...good luck

 

[BMW3.0CSi]

Well, it's been a while, but today I had my first drive of the season. Over the winter I didn't test that much because of other priorities. Today I drove a 50 km without 'real' problems, but I didn't made any highway kilometers. While in the low revs it sometimes hampers a little bit, but it never died. The only thing I noticed was that the ignition coil was too hot to my opinion, after 2 or 3 seconds you had to release your hand from the coils surface because your fingers would be burned. I don't know if that is normal?
I felt for immediately after being back home from the 50 kilometer drive and kept the engine running. (I have seen topics which mention that the coil can become very hot with only switching on the contact).

Will try to do something this season with your advice @willies13. Thanks.

 

[adawil2002]

Hot coil is a bad coil. It may get warm from engine heat, yet should be cool.

 

[BMW3.0CSi]

Hot coil is a bad coil. It may get warm from engine heat, yet should be cool.

But it's a brand new coil.... I have to check some other posts here on the forum then why it's getting so hot or what the failures can be.

 

[sfdon]

Always start your trouble shooting with a fully charged battery.

Always.

Make sure your volt meter works correctly


Check battery voltage - fully charged battery is 12.6 volts

Don’t waste your time if the battery is not fully charged

Pull fuel relay under rear seat

Pull spark plug and place on valve cover with plug wire connected

Crank engine and look for spark.



I have 3 csi’s in the shop if you have questions, need pics.

 

[wilies13]

If you stop the engine, keeping the ignition on and the interrupter (correct by translation service ??) is radomly in "on"-position, then after some minutes the coil will be hot due the continuous current. If you have an mechanical interrupter and not a system like e.g. 123 ignition.

If it is already hot during running engine I can imagine only 2 things:
- The coil needs a pre-resistor. The Bosch ones have a colour code in the web there are a lot of infos about value in ohms.
> Propose to check this and correvt. A missing pre-resistor will cause further things like abbrassion of interrpter.
- More theoretical it could be that the dwell angel is totally wrong (mech. interrupter). But then there should be other tough problems.
I heard about poor interrupters with plastic parts instead of "Pertinax"

- I can not see a correlation to a poor battery.

- Add. you can buy coolant spray. If the problem will reoccur, cool part by part and try to start ...

 

[wilies13]

I forgot:
If there is an electronic interruptor, then it could cause both effects. The engine could suddenly die and/or heat the coil addtionally due to leakage current.
Often is dependent on the temperature of the electronics > coolant spray to identify....

 

[Willem Tell]

Always start your trouble shooting with a fully charged battery.

Good and likely important advice. Driving your car does not really charge your battery as much as you might think, because you're consuming energy at the same time. I have read a drive of 350-500 miles is needed to fully charge a battery, so little short drives tend to drain it.

A weak or drained battery can cause some funky behavior, so put it on a tender overnight before your next test drives. If it's not at 12.6V after a charge, consider the battery.

Probably not your problem, but a fundamental starting point.

 

[zinz]

Coil should not be that hot.

Check this. Are the plugs resistorized? Are the wires resistorized? Is the rotor resistorized?
See where I’m heading with this? None of those components should be resistorized, if they are, the rest of the ignition system has to work much harder to overcome the cumulative R value.
...something to think about.

Ed

 

[BMW3.0CSi]

Hi all, it's been a while since my last post on this subject but I have a new update after some trouble shooting over the weekend. I did some research on this forum, but also some other car forums with specificly searching on the subject 'overheated coil'. Based on that, and together with the Blue Books I started checking the altenator and regulator today. I think a lot of things can be explained after what I have found.

Some additional background info:
I have been driving a couple of times last summer, but always quit close to home with a fully loaded battery (still afraid that the car would let me down..). When the car is not being used I always attach it to a CTEK battery loader. When starting the car the warning bulb of the battery capacity/voltage on the instrument cluster was always lighting up, since I think 1.5/2 years but I can't remember exactly anymore. But after driving for some time it slowly got weaker and weaker and almost went out when being back home. I always thought that it was related to the fact that I drive the car maybe 5/10 times a year during the spring/summer period. With only having the battery loader I assumed that it was a little bit lower on voltage then when you really drive the car with the altenator loading the battery.

Yesterday I checked the voltage as described in the blue book over B+ and D-. While it is a bit difficult attaching the measuring pin of the voltage meter to B+ because of the little amount of space it only gave 0.24V. To be honest I couldn't believe that, I also did a test with a bulb tester but that also didn't glow. For me that was the sign to take out the alternator and the regulator, but with disassembly of the regulator I noticed that the D- plug was burned away and even the cable was burned through. I never noticed because it was still in the plug looking as being normal.

Whit this knowledge I think I can now explain on high level why the car is showing issues, but I do not fully understand it. Is it correct that if you cut your D- between the alternator and regulator that the battery isn't being loaded anymore? And the question is how this could happen, I think the regulator is broken and that caused high voltage peaks into the wiring harness with finally the D- plug being burned down and even a burned through wire. I also had a small melted headlight plug last year, an indicator instrument light that only worked for one time on the instrument cluster after you turn on your indicator but the indicators on the car still continuing blinking. This might be related to this also, but I think the relais is the issue which is also showing issues since 1.5/2 years.

Finally this should then lead to a heated coil? Is that possible? I need to do some analysis myself based on the findings, but any comments from your side would be appriciated.

I have decided to order a new voltage regulator and let my alternator check by a professional (while I'm not sure if the alternator is an issue anymore).

 

[HB Chris]

It is very common for the three wires from regulator to battery to became frayed, lose their sheathing and come into contact as they are somewhat hidden. If the charging lamp stays on your system is not charging. Your loose wire is the culprit here. To test the alternator run the motor and put your voltmeter on the battery posts, you should see around 14V. With motor off around 12V. If you replace your alternator with a modern single wire model you can run the blue wire directly to the alternator and bypass the regulator with its three wires entirely. Leave the regulator in place with no wires attached to keep a period look.

 

[Willem Tell]

If you replace your alternator with a modern single wire model you can run the blue wire directly to the alternator and bypass the regulator with its three wires entirely. Leave the regulator in place with no wires attached to keep a period look.

That's what I did on my Tii...

 

[adawil2002]

Chris is correct. Had my alternator fail on a trip in 2012 & had it replaced with an internally regulated alternator. We kept the original voltage regulator for cosmetic reasons.

On my '73 Tii in 2011 I noticed the "L" glowing slightly. When I inspected the alternator wires, I was able to pull 2 wires free from their connections with no effort. I stripped back to clean wire & re-crimped them & have been fine since.

 

[JFENG]

I’ve never seen a condenser laying inside of a dizzy! It mounts outside where that rubber

Old Jags put them inside the distributor.

Probably done because the dist was positioned directly under the most likely spot for a coolant leak. But you’re right that inside is terrible from the standpoint of overheating and heat degradation.

I recommend Pertronix, but put a spare module in the trunk. I’ve had three fail on me in 11 years.
John

John

 

[Ohmess]

BMW3.0CSi - If you see the battery light illuminated when driving the car, this means the voltage flowing from the battery exceeds the voltage being created by the alternator. When this happens, the alternator is not charging the battery, rather the car is drawing more voltage that the alternator is pushing and the additional voltage necessary to keep the car running is drawn from the battery.

Any tme you see this light illuminated, you have an electrical problem that might leave you stranded.

 

[tferrer]

A useful little gadget to have is a plug in volt meter for your cigarette lighter. The Motronic brain needs a *steady* 13v to keep its act together. Learned this the hard way with help from Don L.

Here's a link - https://www.amazon.com/dp/B00UCEAKYU/ref=cm_sw_r_cp_apa_fabc_R6L1FbPZTYY4Y