1976 2.0L D-jet, distributor vacuum Options

[Ron914]

@emerygt350
I was asked my a member helping me with my high idle /vacuum leak problem how I currently have it hooked up .This is the diagram I am using .

[emerygt350]

How high is the idle currently?

[Ron914]

How high is the idle currently?

still around 1400 but I need to work out positive verification of my timing . I now have a better idea on doing that by using the TDC (confirmed mark) on the flywheel , plus after running the new 2056 motor now for approximately 3-500 miles I probably need to adjust the valves .This may be the noise I'm thinking could be coming from the exhaust , so another reason to be spot on with TDC. If I move my distributor a little advanced or retarded I can get close to 1000 rpm but after putting away in the garage for the night I found it doesn't want to start unless I undo the distributor adjustment I did the night before . More things to work out still but life is always busy for me so I don't always get right back to it that soon.

[Ron914]

I think I might have a bad decel valve but others told me that probably is not the cause as it's making an emissions device.

[IronHillRestorations]

You might want to make sure the advance mechanism is working properly, it might be sticking.

[emerygt350]

That was my first thought. But you don't have your advance hooked up right?

Best thing to do is cap everything now and slowly readd. Get it warm, then plug it all. Aar, retard, decel, etc. you can even check the mps by pulling the vacuum off the plenum while it is running and plug it with your finger. It will be rich but it shouldn't rev once you plugged it. If you have a vacuum pump you can just put 20inhg in the hose going to the mps and plug the plenum.

If everything is plugged and it's still at 1400, grab a can of carb cleaner and start spraying around the plenum, the runner boots, and the injectors. If you don't get any change it has to be your timing (or possibly that combined with a lean idle mix).

[emerygt350]

Also ... 1400 just happens to be where the aar puts the motor during warm up...

Here is a cold start this morning 34F showing idle as the car warms. Today it would take quite a bit of driving (maybe 15 minutes) before I would be warm enough for idle to hit 'normal' hot idle. Even after the AAR is closed the richening from the charge temp sensor and the CHT seems to keep it up around 1100 untill everything is all happy.

https://www.youtube.com/shorts/fQ3FCZQWKKM

[Ron914]

That was my first thought. But you don't have your advance hooked up right?

Best thing to do is cap everything now and slowly readd. Get it warm, then plug it all. Aar, retard, decel, etc. you can even check the mps by pulling the vacuum off the plenum while it is running and plug it with your finger. It will be rich but it shouldn't rev once you plugged it. If you have a vacuum pump you can just put 20inhg in the hose going to the mps and plug the plenum.

If everything is plugged and it's still at 1400, grab a can of carb cleaner and start spraying around the plenum, the runner boots, and the injectors. If you don't get any change it has to be your timing (or possibly that combined with a lean idle mix).

After we installed the motor my brother in law used his vacuum pump and verified the advance plate movement in the distributor but he does not live by me so I will go and invest in one . The vacuum off the distributor is no longer hooked up ,it is open to to air now. Once I got that part correct things got much better .You were correct in your previous comments about that and I had it connected wrong. I think I could be close but something is still not quite right.
So let me make sure I understand .
1) get car warmed up with everything hooked up
2) then unplug all lines connected to the plenum and plug them.
3) Now re add those unplugged lines one at a time to the plenum looking for a change
4) while not running unplug the line going to the MPS from the plenum and put 20inhg on the unplugged line that goes to the the MPS and plug the plenum then start engine and check again?

[emerygt350]

That was my first thought. But you don't have your advance hooked up right?

Best thing to do is cap everything now and slowly readd. Get it warm, then plug it all. Aar, retard, decel, etc. you can even check the mps by pulling the vacuum off the plenum while it is running and plug it with your finger. It will be rich but it shouldn't rev once you plugged it. If you have a vacuum pump you can just put 20inhg in the hose going to the mps and plug the plenum.

If everything is plugged and it's still at 1400, grab a can of carb cleaner and start spraying around the plenum, the runner boots, and the injectors. If you don't get any change it has to be your timing (or possibly that combined with a lean idle mix).

After we installed the motor my brother in law used his vacuum pump and verified the advance plate movement in the distributor but he does not live by me so I will go and invest in one . The vacuum off the distributor is no longer hooked up ,it is open to to air now. Once I got that part correct things got much better .You were correct in your previous comments about that and I had it connected wrong. I think I could be close but something is still not quite right.
So let me make sure I understand .
1) get car warmed up with everything hooked up
2) then unplug all lines connected to the plenum and plug them.
3) Now re add those unplugged lines one at a time to the plenum looking for a change
4) while not running unplug the line going to the MPS from the plenum and put 20inhg on the unplugged line that goes to the the MPS and plug the plenum then start engine and check again?

Is your retard hooked up currently? That would nearly bring it down to 900 from 1400. I assume it is hooked up and doing its thing. You may want to play with that vacuum pump and the distributor. When you give it vacuum on the retard does it drop down to 900? Does the idle rise when you remove and plug the vacuum to the retard side of the can?


I believe your list above covers all the bases. Hopefully it isn't a combination of things so keep an eye on any smaller changes.

[Ron914]

Good morning Emery ,
I purchased these last night so I can continue trouble shooting my idle issues .
I want you to to know how much I appreciate yours and others help and patience with me as I try to figure this problem out ,my only regret is I didn't figure out how to post photos on this site 3 years ago . Too bad you are on the east coast and I am on the west coast, would really enjoy to meet you one day and buy you what ever your favors of drink is and chat or do a bike ride with you .

New question a bit out of order until I resolve my current problem .
I am not a mechanic but definitely a do it yourself guy , I hate to play and would rather learn.
When I had my motor rebuilt I upgraded to a 2055 cc .
I see a lot of comments here on the MPS .
You seem to be one of the members that understands the MPS well .
My question is a bit out of order but it seems I might have a future issue because of my upgrade to 2055 or 2056 the shop that put the lower end together for me wrote 2055 on mine .
I will not be able to get to my car today but plan on working on it tomorrow if its not raining .my garage is very tight as you can see so only way I can work on my car is to move something out side .

[emerygt350]

Oh the trouble we go through (IMG:style_emoticons/default/wink.gif).

Someday I hope to take a long road trip in the 914, who knows how far I will get. I have cousins in Huntington Beach, great uncle worked for Howard Hughes.

Tuning the MPS is a bit of a beast. After a couple of years poking at it I think I have determined why it is so hard to get perfect on my 2056. The vacuum profile of the motor is different at cruise. This will also play havoc with your EGR and retard. When it comes time the first thing you will want to do is get a good baseline of what vacuum you are pulling at idle and cruise. My engine pulls so much more than stock that it was activating the retard circuit when it shouldn't have been and same with the advance. Once you start reaching into the throttle it doesn't matter so much but it's the part throttle bits that really get screwy. Don't forget you can use that pump to monitor vacuum in the plenum. Will be interesting to know how much yours is pulling.

[Ron914]

Great to hear you have family in Huntington Beach , maybe it's possible to meet up one day . I have always wanted to ride my bicycle up the up the north east coast during fall sometime . That is not in the cards for a while as I retired 5 years ago and I take care of my 90 year old mother so getting much of a chance for any type of vacation /adventure is just impossible for me right now . I am thankful I can at least get out of the house a few hours a day while she is sleeping and get a shortbike ride in . Seems like we share similar interests road bikes and 914's . I have ridden down the coast of California a few times and can't tell you what a great ride it is an d the comrade of my cyclist friends . This 914 project was sort of a bucket list thing for me since I was no homebound after I retired ,had to find ways that helped my mental state . Again as I said I have skills but I never considered auto mechanics one that I was good at .I have a back up Trek Kamtail carbon bike if you ever get a chance to come visit you family I could let you ride it and I have some great hills and trails to ride on here .I ride a 56cm bike if that would be a fit for you bring your own saddle a pedals and your more than welcome .Hers a photo of some of the crazy (as I am told type of riding )I do ,or used to do .

[emerygt350]

Very cool. Nothing bike related going on for another month here. That and I am fighting pneumonia at the moment. Yuck.

Felt very Bavarian this morning on the way to work. Supposed to be thunderstorms and rain in another couple hours.

[Ron914]

Very cool. Nothing bike related going on for another month here. That and I am fighting pneumonia at the moment. Yuck.

Felt very Bavarian this morning on the way to work. Supposed to be thunderstorms and rain in another couple hours.

Love it , your car is not a garage queen ,although I don't think I would drive my in the snow ,shows how much you love that car .I get it .
Nice looking car

[emerygt350]

If there is salt she hides in the garage. Otherwise I drive it as much as I can. I wouldn't drive it on real snow though.