Distributors and Trigger Points (New Dizzy Installed), Troubleshooting Parts - CHT appears bad Options

[tvdinnerbythepool]

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! (IMG:style_emoticons/default/beerchug.gif)

[yellowporky]

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?

[r_towle]

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

Rich

[rjames]

After fully warmed up with a tuned and rebuilt MPS

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.

[Rand]

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.

[Arno914]

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?


(IMG:http://www.914world.com/bbs2/uploads_offsite/up.picr.de-24260-1631606222.1.jpg)

[tvdinnerbythepool]

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).



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.

(IMG:style_emoticons/default/beerchug.gif)

[tvdinnerbythepool]

Shaft crud upon removal

[tvdinnerbythepool]

Clean baby!

[914_teener]

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.

[tvdinnerbythepool]

@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 (IMG:style_emoticons/default/beerchug.gif)

[914_teener]

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.

[tvdinnerbythepool]

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.

[914_teener]

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.

[Jett]

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

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

[tvdinnerbythepool]

@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 (IMG:style_emoticons/default/beerchug.gif)

[r_towle]

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

[tvdinnerbythepool]

@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!

[tvdinnerbythepool]

@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]

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.