1976 2.0L D-jet, distributor vacuum Options

[Superhawk996]

MPS should not be bleeding down noticeably

Redo - make sure you have tight hose connections to Mighty-vac.

Continued leakage means MPS diaphragm cracked or bad seals / gaskets but cracked diaphragm is by far the common failure.

[emerygt350]

And your car should start with the vacuum hose off the mps, it will just be rich, which is what you need. Do what hawk said just to make sure. If it is leaking that means it's rebuild time for that mps (easy) and I am not sure if anyone has the diaphragms.

Your vacuum looks okish so at least that is good news. Until the mps is sorted I wouldn't bother touching anything else.

The hunting is likely a lean mix at idle. Go to 6 o'clock on the ECU. It could also be the leaking mps giving weird signals to the ECU.

[Superhawk996]

I am not sure if anyone has the diaphragms.

Tried to look on CFR / tangerine site - not showing any products and site is squirrelly - is Chris OK? Is he no longer supplying repair diaphragms?

[Ron914]

MPS should not be bleeding down noticeably

Redo - make sure you have tight hose connections to Mighty-vac.

Continued leakage means MPS diaphragm cracked or bad seals / gaskets but cracked diaphragm is by far the common failure.

Phil, @Superhawk996
I was told by Bruce only pull 10inhg on my MPS so I did that and set my stopwatch .
I pulled 10inhg vac on my MPS and timed it. It took apx. 1:12 seconds to bleed down to 5inhg and about 2:30 to zero inhg vac. does this show a bad MPS and part of my problems getting my new motor to run properly?

[Ron914]

And your car should start with the vacuum hose off the mps, it will just be rich, which is what you need. Do what hawk said just to make sure. If it is leaking that means it's rebuild time for that mps (easy) and I am not sure if anyone has the diaphragms.

Your vacuum looks okish so at least that is good news. Until the mps is sorted I wouldn't bother touching anything else.

The hunting is likely a lean mix at idle. Go to 6 o'clock on the ECU. It could also be the leaking mps giving weird signals to the ECU.

@emerygt350
I decided I need to get my priorities in order and quit beating my head against the wall .
I jacked my car up on drivers side and put in 5th gear and turned my wheel until the only timing mark I know of showed up on my flywheel .

This the what I see in my fan housing view hole . no mark in the V I remember when I installed this that there was one mark only a red O.

I am going to use this flywheel mark assuming it is TDC and check my valves first .then try my timing by using this mark on the flywheel.
Thoughts?
Not sure why I put that sharpie mark on the fan blade or why the red O does not show up in the V .

[emerygt350]

Hmmm... I put a new to me fan on mine when I rebuilt it and it was from a later bus type 4 and it had no marks. I marked mine by lining it up with my original and then tdc while it was in the car. You may have the same kind of thing going on. I would verify TDC and mark it yourself. Not sure if the flywheel can be 180 out. I mean anything is possible I guess.

And your mps should hold air much longer than that. It needs to withstand 17 at a minimum anyway. Holding at 10 seems odd to me but it doesn't really matter in your case.

And I am not sure if that kind of a leak means you are out of luck or not. I think I would start looking for a kit and while that is going get that timing mark figured out.

So many questions. I would get cylinder 1 at TDC using an Endo scope or a chopstick (using the tire in 5th gear technique). Verify the mark on the flywheel, and verify the position of the rotor. Then I would make a nice new mark on the fan and time the engine.

[Superhawk996]

And your mps should hold air much longer than that. It needs to withstand 17 at a minimum anyway. Holding at 10 seems odd to me but it doesn't really matter in your case.

(IMG:style_emoticons/default/agree.gif) Somewhere in these threads you’ll find a bled down time range from something can’t be less than 5 in Hg starting from to 10 in Hg (Brad Anders site) in less than a minute, to using like 10-15in Hg and having it hold without dropping at all for 10 minutes and if I recall the automobile Atlanta site says something like should hold indefinitely. Truth is somewhere in between there.

Personally I believe longer is better. There are so many threads where people struggle with a diaphragm that is hairline cracked that it isn’t worth it to me to be chasing your tail if it seems borderline. Once you see how it’s all built it’s easy to see how a diaphragm can hold at lower vacuum but when the diaphragm deflects and leaks more at high vacuum (ie idle and deceleration) it could cause problems.

Just pulled 15 in Hg on a unit I rebuilt about 6 months ago. Hasn’t leaked at all at 10min mark as I write this. Just wanted to re-test it before giving you numbers I can support with data and a video.

[Ron914]

Hmmm... I put a new to me fan on mine when I rebuilt it and it was from a later bus type 4 and it had no marks. I marked mine by lining it up with my original and then tdc while it was in the car. You may have the same kind of thing going on. I would verify TDC and mark it yourself. Not sure if the flywheel can be 180 out. I mean anything is possible I guess.

And your mps should hold air much longer than that. It needs to withstand 17 at a minimum anyway. Holding at 10 seems odd to me but it doesn't really matter in your case.

@emerygt350 @Superhawk996
Looks like I will need a rebuild on my MPS along with my TB ,my understanding is no one likes to do this , I could buy one from Jeff Bowlsby but he states not tuned for a 2056 .My fan has a red mark and a O after assembling the motor we noticed when starting to time it that the mark was no longer viewable ,this has been a thorn in my side every since ,my only thought was pull the motor to extend the mark . My other thought was to get my girlfriend to watch for the mark after I jack up the car again and rotate my tire while in 5th gear and maybe she will be able to see it . I wish I had a photo of the mark ,it definitely was there a redline and O . Still not sure if it was the original fan of this 1976 914 since so much could have happened before I purchased the car .
I believe @BlueLightening had the same issue and used the flywheel mark . I can call or go visit the lower end builder of my motor and try and verify that the mark he put on my
flywheel is actually TDC.
I am positive my fan only had the one mark on it though.
I am going to try and time my car tomorrow using that mark on the flywheel as BlueLightening did just help a non mechanic with a couple of questions please.
If I read correctly I need the retard from my dizzy disconnected and hold the throttle open to 3500rpm when I put the timing light on the mark on my flywheel .This might have to wait since I won't be able to do this without my girlfriend till the weekend . I am going to Air/Water tomorrow so maybe Sunday instead and I will report back .

Emery I did move my ECU setting to 6:00 position and moved my dizzy a bit until I got it to idle close to 1000rpm ,it still takes a second or two before the idle comes back down though when I run it up to 2000 so I will look at the dizzy moveable plate and clean/grease and hopefully this will help.As a side note we did use the mityvac to check that the plates moved when vac was applied when first assembling the motor.

[Ron914]

If I can find parts I will need some coaching on rebuilding my MPS ,George at AA has one but he wants something like $600 for it and I really don't want to spend that much ,I am getting to deep into this project already .Mark said he would rebuild my TB for around 150 plus shipping so I will reach out to him Monday after I mess with my timing some more . One more question with the bad MPS and TB am I wasting my time trying to time my car this weekend ? Maybe Patrick Motorsports has a rebuild kit for the MPS.

[Ron914]

Nothing on Patrick's site
I just found this but not sure if available , I'll have to go back and check again but Is this what I need ?
@emerygt350 , @Superhawk996

[emerygt350]

That's part of it. On a 76 if you have the original ECU and mps I don't believe you need the spacer but Chris would know. Did you have two mps units? Hard to remember. What is missing from that picture is the diaphragm. That is what you really need. The stuff in the picture allows you to tune the mps for a 2056. Tuning isn't hard it just takes patience, and an afr gauge.

I wouldn't bother running the engine up to 3500 while you are under it. Just set it to around 8 or 9 btdc at 1000. Your weights will start kicking in around then so you want it to be a little more than the 7 or 8 btdc you would do at 900.

And get those plates cleaned up real nice. And the weights. Everything should move really easily in that dizzy.

It would be interesting to see what the plenum vacuum is now at idle that you stopped the hunting.

[Superhawk996]

Was revisiting a previous thread

Found this:

Here's the latest news:
I ran out of diaphragms last month. My supplier of Be-Cu stampings isn't going to make them for me anymore. It was 8 years since my last order of 250 pcs.
I may not have any new kits available for the remainder of 2024, until I work out a new plan. Right now I'm looking into an alternate material created to replace Be-Cu with a non-toxic alloy.
The material I found is also a copper alloy, with similar flexural properties after heat treat.

Without diaphragms we are all screwed.

AA just had a thread posted looking for core housings so I’m not sure what they are using for diaphragms? Different supplier than Chris? (IMG:style_emoticons/default/confused24.gif)

[Ron914]

Was revisiting a previous thread

Found this:

Here's the latest news:
I ran out of diaphragms last month. My supplier of Be-Cu stampings isn't going to make them for me anymore. It was 8 years since my last order of 250 pcs.
I may not have any new kits available for the remainder of 2024, until I work out a new plan. Right now I'm looking into an alternate material created to replace Be-Cu with a non-toxic alloy.
The material I found is also a copper alloy, with similar flexural properties after heat treat.

Without diaphragms we are all screwed.

AA just had a thread posted looking for core housings so I’m not sure what they are using for diaphragms? Different supplier than Chris? (IMG:style_emoticons/default/confused24.gif)

Well that's not good news for me (IMG:style_emoticons/default/blink.gif)

[Superhawk996]

I’m getting old - I don’t remember seeing that - possible I just missed it but like you I finally got into Tangerine site this evening and didn’t see the diaphragms listed anymore.

You might want to talk with Chris - it seemed like he was looking for an alternate supplier.

[Ron914]

I’m getting old - I don’t remember seeing that - possible I just missed it but like you I finally got into Tangerine site this evening and didn’t see the diaphragms listed anymore.

You might want to talk with Chris - it seemed like he was looking for an alternate supplier.

The kit does not show a diaphragm only a spacer ring for the diaphragm.
George shows he has one but I may need to call first and send in my old one , he will give you $75 per is post for anyone who sends him one but wants a $250 core charge .

Still pricey but what choices do I have

[emerygt350]

That's tough. The rebuild kit plus the tuning equipment was about 280 if I remember right. Problem is, in the end you will need Chris's kit to tune the mps. So you will still need the screw driver tool and the outer screw from him in the end. Your cht resistor plus that AA mps will probably be enough to fudge it for a while though. You would also need an afr but you were going to need that regardless of your mps diaphragm. The djet rabbit hole is deep. I would not worry about the tb at the moment. I left mine for a couple years before I had it repaired. It really is just a vacuum leak and you can compensate for that with the idle screw.

[Ron914]

That's tough. The rebuild kit plus the tuning equipment was about 280 if I remember right. Problem is, in the end you will need Chris's kit to tune the mps. So you will still need the screw driver tool and the outer screw from him in the end. Your cht resistor plus that AA mps will probably be enough to fudge it for a while though. You would also need an afr but you were going to need that regardless of your mps diaphragm. The djet rabbit hole is deep. I would not worry about the tb at the moment. I left mine for a couple years before I had it repaired. It really is just a vacuum leak and you can compensate for that with the idle screw.

Could you recommend an AFR for purchase There are many to pick from with wide range of pricing . I still have the Bursch muffler I got from another member and since I need to have the muffler part replaced I can also have a bung welded in for use of an AFR , as far as the gauge will I need to install that somewhere in my car or can it be used only when tuning while outside of the car . I will call Chris today and see if he has found a replacement for the diaphragms yet .Not sure if I want to order the MPS from AA .
I did end up re-installing that inline resistor back into the CHT circuit ,car seems to run better with it . I am once again wondering about the past history of my car , The screw/nut in the butterfly plate in my TB ,the resistor that was in the box of parts and the fact that the decel valve adjustment was turned all the way in rendering it inoperable( maybe only to pass a visual smog check but out of the loop for performance ). I have been seeing a lot of WTB for MPS in the classifieds lately .

[Ron914]

I found this AFR on a website ,What do you think ?

I had purchased a used CHT with gauge from a member but gave it away because it always showed 100 degrees and was only a 52mm gauge which did nut fit as a replacement for my clock in the center console. I just found this sender but still cannot locate a 60mm gauge .

[TJB/914]

Hi Ron,
I sent you a PM this morning.
I have what you need, repair kit & rare OEM in the box 2.0 MPS.
Tom your 914 friend (IMG:style_emoticons/default/smilie_pokal.gif)

[Superhawk996]

I’m getting old - I don’t remember seeing that - possible I just missed it but like you I finally got into Tangerine site this evening and didn’t see the diaphragms listed anymore.

You might want to talk with Chris - it seemed like he was looking for an alternate supplier.

The kit does not show a diaphragm only a spacer ring for the diaphragm.
George shows he has one but I may need to call first and send in my old one , he will give you $75 per is post for anyone who sends him one but wants a $250 core charge .

Still pricey but what choices do I have

Ron

I’m going to rant for a minute bear with me

The Automobile Atlanta “euro” sensor is pure Bullshit. Although it may indeed richen the mix along with the CHT resistor this does not somehow make it high performance or automatically improve top end performance. Notice there is no data to support this claim of improved performance. It’s not recommended in PET. There is no dyno data, or AFM data here to back this claim.

This is AA at their worst. In addition to this Euro performance bullshit. The “euro” sensor is just the one year 037 sensor that was for the 73’ 2.0L. So rather than keeping these sort of oddball 037 one year parts available for the 73’s that MUST use them - they are being erroneously propagated to other cars they were never intended for.

In addition, their date ranges for all their MPS parts are erroneous - showing an 043 sensor as fitting 1970-76 2.0L. Let’s start with the fact that there were no 2.0L’s until 73. (IMG:style_emoticons/default/headbang.gif)

Then of course we have the situation where the doctor is trying to buy up cores at $75 while charging $250 for a core? (IMG:style_emoticons/default/chair.gif) I don’t begrudge AA they need to make a profit to survive. Somehow AA has survived while many other Porsche specialty suppliers (Tweeks, Performance Products, etc) didn’t. Obviously he has inventory carry costs, etc., but this just seems a bit excessive and a shitty way to treat the community that he too is depending on. But in all fairness - he’s a survivor. I’m not understanding something. (IMG:style_emoticons/default/confused24.gif) Again, in all fairness, AA does seem to support those that call and need some handholding so he’s obviously doing something right in that balance of “tech support” vs hocking parts. They do stock a lot of parts that no one else does - so there is that upside to what AA provides.

PET call for an 043 sensor for all 74’ - 76’ cars. It is cheaper since you’re not paying extra for the marketing BS.



I would highly recommend finding a good used part from another member vs AA. You’re likely going to need to retune it anyway. This is due to changes in modern pump gasoline, wear / volumetric efficiency changes in your engine vs factory original, and the rebuilt MPS that AA is selling . . . Well we don’t know exactly how those are calibrated. There have been reports that the FCI parts don’t use the Copper -Berillium diaphragm and had varied tuning.