Hey all,

I am still chasing down an intermittent RICH condition when the car is fully warmed up. 1.7L D-Jet

After fully warmed up with a tuned and rebuilt MPS I can come to a stop light and idle steady at 850rpms, next stop light it's bogging down to almost 200-300 and barely running. Then next light it's idling normally again. Some days I have no issues with idle at all, others I do.

I've gone through all the components and troubleshot my way through everything on the PBANDERS list of "my car is running rich". I am as confident as I can be through extensive troubleshooting and testing that my ECU, AAR, MPS, CSV, Vacuum Leaks, CHT, Injectors, Fuel Pressure etc are all good. All new wiring harnesses, plugs, plug wires, cap, rotor, coil, etc.

The ONLY thing I haven't worked on is the distributor.

I am reading up on the possibility of the Trigger Sensor Contacts being warn and bouncing possibly shooting off extra injection pulses...could this be the cause of the intermittent problem?

It doesn't have points anymore, but a petronix I believe.

What do you guys think? Is there an easy test for this or do I replace the trigger contacts or the whole dizzy?


Cheers!

Did you resolve this?
You don’t mention the TPS? How is the throttle body? Sometimes the worn throttle shaft and plate make for sticky and inconsistent return to idle conditions. Although allowing air to bypass would raise the idle but I’d you tuned it to a spot with excess bypass and your intermittent situation is when you have a good seal?

Remove, clean and regrease the distributor advance plates.
I posted a howto
Rmital posted a howto

Rich

How did you tune the rebuild MPS? Typically after an MPS is rebuilt it needs to be tuned for the specific engine it will be used with. If your car is running rich I don't know how you'd be able to tune the MPS to where it needs to be.

How did you test the ECU? I had an intermittent rich issue that turned out to be the ECU. It would work fine for a while, sometimes for an hour or so on a hot day, and then just go rich. Sometimes for intermittent issues the only way to really know is to swap out a part with a known good one.

MPS wouldn't likely be intermittent like that. ECU is usually fail or not, can't see how that would randomly affect idle RPM.

I'd bet it's sticky advance plates in the distributor. Clean and grease. They need to be able to easily move with centrifugal force. Be careful to keep the braided ground wire intact.

A 123 distributor would be a huge upgrade for you.

I have the same issue with my 71-4.
Checked everything on the D-Jet and still random stalling (or almost stalling)when hot.
I will swap the ecu (have a NOS) and see if there is a difference. I suspect that maybe there is a bad soldering somewhere on the print. Had this on a BMW E30 years ago. Drove me nuts until I opened up the brain and found a capacitor came loose. Maybe a search option?

Hey guys!

Thanks for everyone's response. I'll hit each one here...

TPS has been tested and adjusted to specs. I have a replacement board from 914 Rubber but the contacts and OEM board seem to be in good shape. I do have a TPS that is a core for rebuild that I think I will tackle this summer with the new board. I am not 100% that the TPS isn't the issue, it's on my radar but so far tests well.

ECU...Swapped out with another unit with the same result. That's about the extent of my ability to test.

For the rebuilt MPS I installed an O2 sensor in the exhaust with a 14point7 gauge. Not exact by any means but it is tuned to my engine the best I can.

Which brings me to the trigger points. I pulled the dizzy and took a peak. The shaft and points were oily and gunky with some chunky oil clods on both. (I have never removed or touched this so it may have been a while).

Click to view attachment

Points were slightly worn and over spec. Thanks to @nordfisch I was able to fabricate the jig to re-center the points to spec. I am now waiting on some proper points grease to lube the shaft and points. Then re-install, timing and test drive.

Appreciate the thoughts and will report back in a few days.

Shaft crud upon removalClick to view attachment

Clean baby!Click to view attachment

That dizzy is worn.

Look at the plate on the trigger points.


I'd pitch it and get an electronic distributor to answer your question.


You'll be chasing your tail otherwise. BTDT.

@914_teener
I take it you are referring to the circle wear marks on the plate?
I did notice that. What is that caused by? No way to salvage this?
The reason I ask is I have a lead on a NOS set of points at a great price but will this dizzy destroy the new set?
Thanks for the input

What do you think? That's normal?

So you think you want to spend near $100 for a set of trigger points and what is the expectation?

Since you have the dizzy out and you see there is a problem, take care of it.


I have but only one conclusion from looking at your pictures....the shaft is worn and putting a new set of trigger points will accomplish....not a whole lot... since you asked. I could be wrong but that what it appears to be. What about the advance plate that Rich posted about....has that been cleaned up?


BTW...have you tested the vaccum advance pots on it? Because if you haven't, there could be a vaccum leak there causing your mixture to run rich and advance curve to be retarded.

So if you haven't tested the dizzy....you haven't tested all of the FI components.

When I restored my car I took ALL the FI components off it and redid or cleaned everything and tested everything....except checking the dizzy. I cleaned it but it would not idle steadily. Once I replaced it with an electronic unit....it ran like a raped ape and I didn't touch it for years with expection of cleaning the engine bay every so often.

With D-jet you need to check else everything first before you start messing around with the mixture on the MPS if it teste good.

Replace....or rebush and rehab the dizzy. That'd be what I think. Anything is salvagable just depends how much time and money you want to spend on it.

I don't mean to dampen your enthusiasim, good for you for tinkering, but seems like you are spinning your wheels and throwing parts at a problem.

Post a pic of your wiring harness. What is the condition of that component? I chased a cracked wire for a month and then just said screw it...took everything apart and got a new one from Jeff Bowlsby.

That dizzy is probably 50 plus years spinning at high RPM'in heat, moisture ect.

Good luck.

I didn't think it was necessarily normal, but this is the only 914 distributor I've ever seen and the only set of trigger points I've ever seen. So I didn’t know what normal was. Now I do.

I do like to try and repair and revive as we live in a world where we seem to just toss shit out if it isn't perfect.

Having said that, if the consensus is a worn distributor that will need repair or replace, I am fine with that.

As noted in my first post, all new harnesses from Mr. Bowlsby and 914 Rubber. I DO believe I have gone through and tested each component per Bosch Manuals with the exception of the distributor which is where we are today.

The wheels are certainly spinning but I am not throwing parts at problems. I am on here looking for solutions. I have not gotten to the advance plates yet but it's on the list. Wanted to resolve the points issue first.

The trigger points won't be resolvable unles you re-hab the dizzy and test the vaccum cannisters. Keeping on point with your post....will cause it to run rich.

I had quite a time finding parts for the vaccum can and as you may know some of the parts (on the dizzy) are now unobtanium even when Brad Anders did his site.

It is the main reason I ditched the stock dizzy....just wasn't worth it for drivability reasons...at least for me.

We recently sent our distributor out for rebuild… This is a recent thread…

http://www.914world.com/bbs2/index.php?sho...=355553&hl=

@jett thanks for the info and link

@r_towle thanks for the quide to cleaning the plates etc.

This is all cleaned up, greased and put back together.

Plan is to get by the rest of the summer with this setup and then pull the trigger on a 123Dizzy as a winter project. Want as many days on the road as I can before the PNW rain hits

Thanks for the feedback -R

So, does the odd idle condition still happen?
Advance plates with 40+ year old grease will do that.

Btw, far too much grease on the FI trigger points, not normal at all.

Rich

@r_towle will try and fire it up tomorrow. Only had time to reassemble tonight. I agree, real mess in there with the trigger points!

@r_towle will try and fire it up tomorrow. Only had time to reassemble tonight. I agree, real mess in there with the trigger points!

It’s the advance plates that the points mount to that get stuck in the wrong position and cause strange idle conditions.
There are two plates, with a ball bearing between them.
The old grease is more like glue now.

Agreed, that grease hadn't been grease for a while, haha!

@rand Agree. Was not suggesting the problem was the MPS but was just pointing out that if would be hard to tune the MPS if their were issues elsewhere (like intermittently running rich).

Another vote for the 123 distributor. I replaced a stock distributer that was in good shape and still noticed a big improvement.

My Fuel injectors stoped firing? I pull the dizzy cleaned the contacts too, 2 started working, this dizzy is done? What do I replace it with? #123? Part?

Dose anyone make the 2 points pice? Insert? Mouth pice?

@Solocholo Dang! At least we aren't the only ones struggling with this!

Ok guys, I bought the 123 Dizzy, Bluetooth and all the tricks.
Getting it installed as we speak and have a question. My curve requires a vacuum hose and I have forever been perplexed as to the 2 dizzy hoses. 1.7L 1970 Djet.

Small Black idle adjust side.

Thicker Green on opposite side.

One is advance and one is retard. Someone please school me as to which is which.

Thanks!

Black advance Green retard

@bobboinski thx!

@Solocholo it looks like the contacts for your FI triggers are partially broken off.( or maybe I am not able to see them clearly?). There are some members who you can source them (also can re-adjust to factory spec with special tool) but reading through the comments I received it was clear that swapping in a new modern dizzy is the way to go. Expensive...but what isn't these days. Will report back later today with how my engine is running. edit....mix up in shipping. Got the wrong one so now delayed until Tuesday.

Hi to all,
the 123 has a big disadvantage you should have to know, and some more issues:

The injection timing of the original set is optimized - injection is done during the stroke the cylinder gets air.
The 123 ignores this and injection is being synchronized with the ignition.
This is suboptimal and takes the main advantage of the D-Jetronic over the L-Jetronic away.

Users who report great benefits at the 123 won't have had a fully checked and correctly adjusted original distributor before.

The original distributor's life will be another 50 years and it will still be repairable then - what about the electronic components of the 123?

Regards
Norbert

Hmmm, I read that the original design set the injectors up in two banks. There are 4 cylinders and only two triggers. One cylinder would get it right before the intake stroke, the other fires as well but the charge just has to wait in the manifold till the intake opens.

"An additional input is required so that the ECU will synchronize the fuel injectors with the piston strokes. It therefore receives signals from a set of dual Trigger Points in the base of the ignition distributor. Each of the two points controls two injectors (in our four-cylinder motors, anyway)"

"Note that output to Injectors at pins 3, 4, and 5, 6 run through 6Ohm 5Watt Resistors. These serve to limit the current applied to Injectors (See also: Dropping Resistors) and effectively drop the voltage actually applied Injectors to 3V. They are then tied together internally to the transistor switches, therefore, Injectors fire in pairs! 1, 3 together, and 2, 4 together."

https://www.sw-em.com/bosch_d-jetronic_injection.htm

And other sources (Chilton's)

Got the distributor installed, I opted for the Bluetooth one for the flexibility in curves...Starting to worry I shouldn't have done that.
It doesn't come with any pre-programmed curves and I am having a hard time finding the OEM curves for my distributor....any input?

My distributor was the 0 231 174 001 for a 1.7l Djet.

I have a call in to the 123 rep but am hoping someone on here may have the info I need.
Thanks!

Nothing you can download from the website?

Really interested to hear how it works out.

Does this help? Around post #102 #132.

http://www.914world.com/bbs2/index.php?sho...8153&st=120

Hey Guys, Thanks for the response.
Long story short, I ended up with 2 Distributors - Bluetooth and a Non Bluetooth. I have opted to use the non bluetooth version. Setting A with Vacuum advance. I could not for the life of me get the thing to run with the bluetooth version with proper curves programmed.

Here is where I am at. I replaced the dizzy due to obvious wear and running issues but it did NOT solve my issues...
-Wildly varying A/F readings
-Inconsistent idle
-New issue noted during all my misery today....quite a bit of white smoke coming through the oil filler tube with the cap off. I was surprised by how much.

I think the motor may just be too damn worn out and need a rebuild. I plan on doing compression test tomorrow, but I think all the smoke coming out of the oil filler cap is already my answer.

I'm also not convinced I don't have an ECU issue that is causing such big swings in A/F ratios.

I'm tired and annoyed and another $600 deep with a shit running car....signing off for the night. Ugh

Here is how I would troubleshoot this.
1) put original distributor back in, but clean and regrease the advance plates
2) disconnect all vacuum lines at the plenum, cover all holes with tape.
Leave just the MPS vacuum line attached.

You now have three things that control the idle A/F mixture.
MPs, tps, and CHT
TPS is not moving….so at idle it should have no major impact, but take the lid off and look fir damage.
CHT, measure it hot and cold….post findings for advice
MPs, you need to test to verify it holds a vacuum.

Rich

If all those tests pass, you have and air leak or a fuel delivery fluctuation.

I remove the fuel hose to the cold start injector and route a new hose around that injector. Mine has been off for years, it’s fine without it.
That injector does leak

If fuel pressure is good then you are looking for an air leak.
The first suspect is the AAR
Then a cracked plenum
Then valve settings
This assumes you did the initial test of removing and blocking off all ports to the plenum.

Everyone always forgets to mention/look at the PCV. Think I have had more d-jet issues caused by iffy or outright broken PCVs than any other component.

All great suggestions, and I would start with the compression.

Thanks all.
I've made a list with the above and will get to work!
Gluten for punishment I guess

CHT cold (63 degrees F) 49.5K ohms

Well...there's your problem! (At least part of it right?)

Running part 012 from 914Rubber. According to PBanders I should be at 2.85K ohms at 61F. Previously tested good but now it doesn't.

Still testing the rest of the above items.

Thoughts?

What are peoples experiences between the URO (part 041) vs the 914rubber (part 012)?

I'm always the first to support Mark and the guys over at 914...maybe I just got an intermittent sensor which I've heard is not unusual.

I would start with that blow by (compression test).... I know it can be scary but if you have big mechanical issues going on your CHT isn't really going to matter...

Update below

CHT: measured 49.7K Ohms at 63 degrees (OUT OF SPEC - NEW ONE IN THE MAIL)

MPS:
-Vacuum holds all day long at 15"
-Calibrated with Wavetech to PBanders specs, very close specs to another sealed unit I have to compare to.

TPS:
Tested perfectly, Mild wear on the Board but not needing replacement. Cleaned and re-calibrated.

Compression test: These are cold numbers, will repeat when new CHT installed with some hot numbers.
#1: 145psi
#2: 150psi
#3: 155psi
#4: 155psi
Pleasantly surprised by those numbers, all within 10psi so whatever wear exists is nice and even.

Will install new CHT hopefully tomorrow night if it gets here in time.

Still need to check the intake plenum and possibly bypass the CSV. I am not convinced it's a vacuum issue as I have very low idle issues, not high, but will inspect.

Really looking like the CHT is the culprit or the ECU. And now I have the infamous modified 13mm deep socket, Lol

The engine is designed with particular vacuum leaks expected, like the pcv.

Does your idle screw do anything at all?

i have the d-jet as well but '75 so they are set up just a bit different, sounds like once you hvae a good CHT( i have 3 on hand just in case) you will get it going, but, did you try to get new set of trigger points plate for the FI triggers? they are out there, i have several but will not part with them as i keep them for my OEM distributor for back up in case of 123 failure and for originality etc .
Anyway i have run the 123 for 3 years and it is doing fine, i dont have vac advance so running Curve D for no vac advance for a '75.
set your timing, follow instructions, verify proper function of CHT and MPS before you throw the 123 aside., Keep your OEM one, get a set of fi tp plate contacts and get Norburt's calibration tool for the FI triggers.

@emerygt350 idle screw does work and is very effective in adjusting idle speed

@drphil914 I am running the analog 123 distributor for now. I will keep the OEM, source some trigger points etc but hope the 123 will be the way to go.

Waiting on a new CHT from 914 and will also get a URO as a spare. Hope this thing is up and running soon. I will troubleshoot the CSV if I still have issues with the suggestion of it possibly leaking and also will suspect the ECU. People say they don't go bad but the one that came in this car was shot. Probably the $30 sensor though!

Thanks for all the help guys.

If the idle screw works can you bring the idle up with it or is it unstable (seems fine but when you drive it it drops low again)?