CSi engine dies after start up —> injectors

[BMW3.0CSi]

Hi All,

I've got a question about my CSi engine. Yesterday I finally was in the position to start my CSi again after 2 years of work (not related to the engine). The car does start, but after let's say 5 seconds it dies. The cold start injector is working fine, because the intake manifold is wet with gasoil. I also put a pressure gauge witin the fuel line and pressure reading is straight at 2 bar pressure. I went through all the steps mentioned on this website: https://oldtimer.tips/en/d-jetronic/troubleshooting and all readings are fine. Got power on my ecu, relais are working, ground checked and ok, cables all in right position, +/- 2.4 ohm on my injectors, etc. Even swopped the ECU with another one, still the same issue. I then did a check on injector #1 by taking it lose from it's support and started the engine. It didn't spray, but I also forgot to connect the ecu connector to the ECU unfortunately . Because I didn't saw any gasoil spray coming from the injector it was clear for me that it had to be something with the distributor (at that moment). So I took it of but later realized that I forgot the ecu connector connecting to the ECU. Nevertheless the injector appeared to be very dry and I already tried several times to get it running. Each time the same, it starts, but dies. So I'm suspecting the ECU does not tell the injectors to operate. Looking in the BMW workshop manual there is a chapter that goes about engine issues related to the electrical system. There is a sentence that exactly mentions my statement, and then saying that you need to replace the condensator. I already did this in the past together with the distributor rotor, rotor cap, sparks, spark wiring, contact points, so that's not what I'm thinking of.

But as I never changed the distributor contact feed I'm thinking about the fact that this could be my issue. I have taken it of and it does look like very old and a bit corroded. See picture below.

I'm also not exactly sure what they mean with 'The releasing points require no maintenance' but you need to 'replace contact feed every 60000km'? What is what in this picture?
See picture below.

So I'm asking your opinion if I'm right in my analysis, because I think I need to replace the injection timing contact (or the condensator)

Thanks for your feedback, Rinke

 

[adawil2002]

Distributor trigger points in the picture above are available new. 123 Distributors has a D-Jet compatible switchable unit.
Your problem is likely not the D-Jet ECU, they are very robust and rarely fail.
Could have a broken wire in wiring harness yet could be as simple as cleaning all the electrical connector pins and sockets.
Most likely problem is the Manifold Atmospheric Pressure (MAP) Sensor. It works in conjunction with the ECU & trigger points to open and close the injectors properly. If the MAP Sensor is not working the car will not run well or at all. Recommend having the MAP unit rebuilt.

 

[sfdon]

It would appear that your cold start injector is working but not your regular injectors.
As a reminder- the wire to pin 50 of the starter is not black, it is red. Red connects to black and 2 white wires.

 

[lloyd]

Hi All,

I've got a question about my CSi engine. Yesterday I finally was in the position to start my CSi again after 2 years of work (not related to the engine). The car does start, but after let's say 5 seconds it dies. The cold start injector is working fine, because the intake manifold is wet with gasoil. I also put a pressure gauge witin the fuel line and pressure reading is straight at 2 bar pressure. I went through all the steps mentioned on this website: https://oldtimer.tips/en/d-jetronic/troubleshooting and all readings are fine. Got power on my ecu, relais are working, ground checked and ok, cables all in right position, +/- 2.4 ohm on my injectors, etc. Even swopped the ECU with another one, still the same issue. I then did a check on injector #1 by taking it lose from it's support and started the engine. It didn't spray, but I also forgot to connect the ecu connector to the ECU unfortunately . Because I didn't saw any gasoil spray coming from the injector it was clear for me that it had to be something with the distributor (at that moment). So I took it of but later realized that I forgot the ecu connector connecting to the ECU. Nevertheless the injector appeared to be very dry and I already tried several times to get it running. Each time the same, it starts, but dies. So I'm suspecting the ECU does not tell the injectors to operate. Looking in the BMW workshop manual there is a chapter that goes about engine issues related to the electrical system. There is a sentence that exactly mentions my statement, and then saying that you need to replace the condensator. I already did this in the past together with the distributor rotor, rotor cap, sparks, spark wiring, contact points, so that's not what I'm thinking of.

But as I never changed the distributor contact feed I'm thinking about the fact that this could be my issue. I have taken it of and it does look like very old and a bit corroded. See picture below.
View attachment 70016

I'm also not exactly sure what they mean with 'The releasing points require no maintenance' but you need to 'replace contact feed every 60000km'? What is what in this picture?
See picture below.

So I'm asking your opinion if I'm right in my analysis, because I think I need to replace the injection timing contact (or the condensator)

Thanks for your feedback, Rinke

View attachment 69998

Unfortunately, much of what is described in English can be lost in translation from the original German.

The simplest question to answer is trigger point maintenance. There is no obvious adjustment for this unit and thus no ordinary maintenance is recommended. The trigger points were originally intended as having a useful life of 60,000 kilometers, after which they were discarded and replaced with a new unit. That said, maintenance can be performed by cleaning the points with suitable electrical cleaning solution followed by proper lubrication of wear points, i.e., the pivoting shaft and most important, the rubbing blocks that contact and ride on the distributor cam. Typically, the only thing that goes wrong with this unit is wear on the point rubbing blocks due to lack of lubrication. Secondarily, the points themselves can be contaminated with oil, grease and dirt, all of which can affect the points function to make and break a decent electrical signal. Again, the unit can be cleaned and regreased, but no amount of cleaning and regreasing will help if the cam on the distributor shaft is worn. Another simple visual check is the state of the wiring, including soldered joints, but obviously an ohmmeter might be used to test continuity and resistance.

I agree with Don that the symptoms you describe suggest that the solenoids that are a part of your six fuel injectors are not being triggered. I doubt this is due to the distributor triggering points in your picture and suspect the issue is related more to a broken, loose or corroded wiring connection. For what it is worth, when your injector is triggered you can feel, if not hear, it "click." So, removal may be unnecessary as part of your initial diagnostics.

Since you describe swapping ecu's, you necessarily disturbed some wiring connections. Remember, there are connections at the ecu, all sensors, all injectors, the Map sensor, the distributor triggering points and even a molex connection in the wiring harness found on some (but not all cars) where the wiring enters the right frame rail near the exhaust manifold. All of these connections can be examined, cleaned and coated with dielectric grease. I hasten to add that decades old wiring that has been repeated exposed to heat and the environment is not a recipe for longevity. Translation: check for brittle and broken wiring, too.

While there are numerous sources of djet information, don’t overlook the factory manual, or for that matter, the owners manual.

__________________________________________________________________________
​

For illustration purposes:

Hint: some good advice here >>>>

Recommended grease for triggering point and ignition point rubbing blocks.

__________________________________________________________________________​

For no particular reason other than saluting the color "Ceylon."

But let's not forget . . . Colorado . . . or is it Inka?

 

[BMW3.0CSi]

Hi All,

Thanks for your quick response with tips and advice. I will do some trouble shooting today based on your suggestions. I indeed also 'stripped' the wiring harness because I had some issues in the past with an hampering engine between lets say 2/4000 rpm. It sometimes felt like it missed a stroke. For that reason I suspected the wiring harness because I always heard a cracking noise when you bowed it, even when you almost didn't touch it. After clearing of the black outside cover I must say that the individual white cables look fine. Will report back when I have new findings.

 

[BMW3.0CSi]

Well, some interesting news after a day of trouble shooting. I did a few checks, first as sfdon says, the wiring of pin 50 is checked, but it is exactly the other way around at my car. See picture. But it always has been like this.

Second, I did the test Lloyd suggested for resistance of the contact points and saw that group 1, injection valve 1-5-3, had an infinite resistance, see pictures. That proofed my first analysis that injection valve nr1 was dry of gasoil. I cleaned the part and in the end it 'worked' again with showing 0.01/0.02 ohm resistance. Question is of course for how long because it didn't work with the first measurements. See pictures.

It looked liked this was the solution, I also did the test with the paperclip and ECU/injectors responded well, based on what I heard (clicking and the fuel pump reacted to get the pressure back on 2.0 bar). But after re-installation of the distributor the car has exactly the same issue again. It starts and after 5 seconds it dies again. I thought again that the distributor was the issue, but after turning the crankcase by hand I heard that the ECU/injectors reacted after each cycle, so the distributor seemed to give the right information to the ECU and the ECU replied.

As 'adawil2002' mentioned I did check the resistance over the pins of the MAP sensor, but they all give the right resistance like its mentioned on the website oldtimertips a previously mentioned.
After this I was not sure what to do anymore, because it all seemed ok. After some rethinking I wanted to see the injection valves spray, because I let them rebuild 2.5 years ago. Since that time they have been sitting in a small carton box.
With taking of one intake air tube I could see if there would be gasoil spraying when doing the paperclip trick on the distributor connector, and it appeared to be that there was no gasoil at all. Then I decide to take of all injectors and test them all outside the intake manifold, what appeared to be is that none is reacting! When doing the paperclip trick I hear something clicking, but al injectors stay dry except for number 3. For some reason after I took it of (gently) it started leaking when the pressure is raised to 2 bar. It didn't happen before, pressure was steady at 2 bar. See picture below, I know it looks like a bit of a mess.

That leaves me with 3 options in my opinion, 1, resistance of the injectors themselves are to high. This is not the case because after measuring all injectors gave the 2.4 Ohm resistance they should give.
2, ground, I took another cable (brown one on the picture) to make ground on something else then the intake manifold bracket for all the ground sockets. Did the same test again, but nothing changed.
Leaves me with option 3, all needles from all injectors got stuck over time. Is that really possible? In that case I will bring the injectors to the company I brought them last time when they overhauled them.
Are there still electrical possibilities I forgot?

Overall, long story, but not there jet

 

[sfdon]

Looks like you let the injectors sit dry after rebuild - very common problem.
Try tapping with a small hammer.

 

[BMW3.0CSi]

Looks like you let the injectors sit dry after rebuild - very common problem.
Try tapping with a small hammer.

Hi Don, stupid question maybe, but I suppose tapping on the housing of the injector, not on the needle itself?

 

[sfdon]

I use a lightweight ball peen hammer and a screwdriver.
Deliver light sharp blows to an edge on the side of the injectors.



How To Unclog Fuel Injectors - YouTube


1:09

 

[E9madada]

I use a lightweight ball peen hammer and a screwdriver.
Deliver light sharp blows to an edge on the side of the injectors.


View attachment 70188
How To Unclog Fuel Injectors - YouTube
View attachment 70189
1:09

I bought a injector tester when trying to resolve running issues. You can connect to an individual injector and set various pulses to check output. Relatively cheap, worked well.

EFI Petrol Fuel Injector Tester 12v system Diagnose problems Store Case 3422 8T3 | eBay

Fuel Injector Tester - 12V. Can be used to locate fuel system faults such as clogged or leaking fuel injectors. sluggish or sticky fuel injectors and wiring harness faults.

www.ebay.com

 

[BMW3.0CSi]

Well, some good and bad news to report. The bad thing, a professional refurbishment company checked their functionality but 3 of the 6 actually don’t work anymore. And the other ones where quite hard to ‘repair’ after ultrasoon cleaning. Sad to hear, lessons learned about leaving injectors in dry storage I would say. Good news is that the issue is found now. Thanks all for your feeback and help!

 

[lloyd]

Glad you have some answers to your quandary, even though they may be bittersweet. We tend to take a lot of things for granted, including the fact that possibly 45+ year old fuel injectors might not live forever. This is especially true if any fuel that might act as a preservative, is allowed to evaporate and become displaced by moisture laden (humid) air. (I guess I blocked from memory that I used to have a big bucket of "rusty" frozen injectors as proof of injector mortality.)

I suppose your post could be a wake up call for some of us to add "stabilizer" (or the like) to the fuel of infrequently driven cars. Since not all decades' old cars are in the same condition, whether it can prevent your issue is unknown. But maybe it couldn't hurt.

 

[adawil2002]

Too bad about the non-functional injectors. Have you been able to source new injectors?

 

[BMW3.0CSi]

Too bad about the non-functional injectors. Have you been able to source new injectors?

Yes, I have 2 myself out of a bunch of engine parts, will let them check/overhaul later this week. And for the one I definitely need I already contacted some guys here in the Netherlands that have quite some parts for the e9. Otherwise I can always buy a new one from W&N or maybe ask here on the forum if someone has some.

 

[BMW3.0CSi]

Glad you have some answers to your quandary, even though they may be bittersweet. We tend to take a lot of things for granted, including the fact that possibly 45+ year old fuel injectors might not live forever. This is especially true if any fuel that might act as a preservative, is allowed to evaporate and become displaced by moisture laden (humid) air. (I guess I blocked from memory that I used to have a big bucket of "rusty" frozen injectors as proof of injector mortality.)

I suppose your post could be a wake up call for some of us to add "stabilizer" (or the like) to the fuel of infrequently driven cars. Since not all decades' old cars are in the same condition, whether it can prevent your issue is unknown. But maybe it couldn't hurt.

That’s indeed the lesson learned, while it’s interesting because with the car being in storage for over 15 years, 3 years in restoration, 5 years of ‘driving’ with only 800km never was an issue. At least it looked like that because it always hampered a little bit. And then, after 23 years and letting the injectors overhaul, all 6 passed the functionality test, 2 years in dry storage ruined them.

I think it’s good to add some conservation additives so now and then, but by just having gasoline on it would already help a lot I think. Or a small drip of oil when it’s put in dry storage.

 

[BMW3.0CSi]

Last update of the story, the car finally made his first kms yesterday after 2 years of work! And, with all of its original injectors! It looks like our injector are maybe more robust then it looks like. As mentioned I had 3 injectors that failed. The needle of the injector wouldn’t move anymore. That gave me 2 options, throw them away or grab a hammer and gently tap on the needle because ultrasoon and tapping on the casting of the injectors didn’t work. Nothing to loose here. To my surprise they all 3 came loose. After testing it appeared that they all worked fine! So our injectors can be treated quite ‘hard’ in order to get them working again!

After driving my first kms with the car I also experienced that the hampering it sometimes had is gone!

 

[Cornishman]

Thank you, nice story and good to know the final resolution so that we can all consider “hitting them with a hammer” if all else fails .
Ever since I started to thinker with things I have to fight to urge to tap things with a hammer, so here is a perfect excuse.
Enjoy your driving.