Honk Honk!.... " yea, I know I am stalled out and blocking the intersection @$$H*L$" Options

[shredtherad]

Hello, hello! The new to me 914 is so rad! Love it... went out for a bit of cruise and about 20+ mins into the drive, while approaching a trafific light ( red ) the car came down to idle and that kept going and poof... stall. It did not start, I blocked the lane and angry SUV's and Tesla's honked at me. I did however get it going again after putting the pedal to the floor while starting and it fired up and drove fine, until... idle at the stop sign. Poof, stall. BUT this time pedal to the floor and fired right up.

Thoughts, where should I begin. I have attached a video of the issue... thanks! Beep Beep.


https://www.youtube.com/watch?v=Mx47LENYFuU

[Big Len]

I think the first general question would be carbs or FI?

[emerygt350]

So sorry! What is the year and fuel system? Carb or injected?

[Superhawk996]

Watched your video. By video title it says stock so I'm going to roll with fuel injected.

Problem is I think you're looking for an easy agreed upon solution to your problem. You're going to get plenty of opinions or "his fixed my car" responses which might help or might have zero applicability to your problem and will keep you running in circles.

If you're new to 914's, and 50 year old fuel injection, you should probably start familiarizing yourself with the Brad Anders pages and the overview of D-jet fuel injection components and how to troubleshoot them.

https://members.rennlist.com/pbanders/DJetP...tm#troubleshoot

(IMG:style_emoticons/default/welcome.png)

[76-914]

So it takes about 20 min's before this happens? If so I think we can rule out vacuum leaks as that would increase the idle speed. Rule out the TPS idle circuit as that would be wonky warm or cold. Does your ECU have a black know on top. If so that controls the idle circuit. You can figit with that. IIRC, it has 22 clicks rich to lean. If that does nothing check to see.if the vacuum is holding on the MPS. That's also in Blander's D Jet Bible. Once warmed up check the ohm reading on the CHT sender on cylinder 3. The values are also listed in Blander's Bible. If you have L Jet disregard everything I said. Good luck and if it (IMG:style_emoticons/default/sheeplove.gif) with you too much throw a Subaru drive train in it. (IMG:style_emoticons/default/happy11.gif)

[shredtherad]

I think the first general question would be carbs or FI?

Good question, it is FI

[shredtherad]

So sorry! What is the year and fuel system? Carb or injected?

It is all good! It is a 73 1.7 with FI

[wonkipop]

factory workshop manual

you can download.

http://p914-6info.net/Manuals.htm

[shredtherad]

Watched your video. By video title it says stock so I'm going to roll with fuel injected.

Problem is I think you're looking for an easy agreed upon solution to your problem. You're going to get plenty of opinions or "his fixed my car" responses which might help or might have zero applicability to your problem and will keep you running in circles.

If you're new to 914's, and 50 year old fuel injection, you should probably start familiarizing yourself with the Brad Anders pages and the overview of D-jet fuel injection components and how to troubleshoot them.

https://members.rennlist.com/pbanders/DJetP...tm#troubleshoot

(IMG:style_emoticons/default/welcome.png)

Yup, 73 1.7 with FI.

Of course I am looking for the easy fix (IMG:style_emoticons/default/smile.gif) but know that is not what is going to happen, I do however need to start somewhere. Thanks for the link! I will be reading that one!

[shredtherad]

So it takes about 20 min's before this happens? If so I think we can rule out vacuum leaks as that would increase the idle speed. Rule out the TPS idle circuit as that would be wonky warm or cold. Does your ECU have a black know on top. If so that controls the idle circuit. You can figit with that. IIRC, it has 22 clicks rich to lean. If that does nothing check to see.if the vacuum is holding on the MPS. That's also in Blander's D Jet Bible. Once warmed up check the ohm reading on the CHT sender on cylinder 3. The values are also listed in Blander's Bible. If you have L Jet disregard everything I said. Good luck and if it (IMG:style_emoticons/default/sheeplove.gif) with you too much throw a Subaru drive train in it. (IMG:style_emoticons/default/happy11.gif)

Excellent! A bunch to dig into here! Thx… many subie 914’s out there?

[mgphoto]

First test is simple, get a hand vacuum pump with a gauge, test the MPS, pull 10 to 15 in Hg and see how long it takes to drop.
Sounds like a cracked diaphragm, runs rich when that happens.

[GregAmy]

First test is simple, get a hand vacuum pump with a gauge, test the MPS, pull 10 to 15 in Hg and see how long it takes to drop.
Sounds like a cracked diaphragm, runs rich when that happens.

Was my first thought, since I had similar symptoms with the 2L D-Jet.

If you're running stock D-Jet, and you have more than say, 75-100k miles on the car, you have no evidence that the diaphragm has ever been replaced, then I'd wager a dollar to every donut that your diaphragm needs to be replaced. The MPS was a very clever design for its time but that diaphragm has a life limit before it will absolutely fatigue.

Mine had those, and other symptoms, and it actually passed the vac test! But when Tangerine pulled it apart to rebuild the crack was obvious. And replacing it transformed the way the car drove.

I like D-Jet, I think it's worth saving. Consider sending your MPS to Chris for a new diaphragm, even if it passes a vac test.

http://www.tangerineracing.com/mpsdiaphragm.htm

[r_towle]

Watched your video. By video title it says stock so I'm going to roll with fuel injected.

Problem is I think you're looking for an easy agreed upon solution to your problem. You're going to get plenty of opinions or "his fixed my car" responses which might help or might have zero applicability to your problem and will keep you running in circles.

If you're new to 914's, and 50 year old fuel injection, you should probably start familiarizing yourself with the Brad Anders pages and the overview of D-jet fuel injection components and how to troubleshoot them.

https://members.rennlist.com/pbanders/DJetP...tm#troubleshoot

(IMG:style_emoticons/default/welcome.png)

Yup, 73 1.7 with FI.

Of course I am looking for the easy fix (IMG:style_emoticons/default/smile.gif) but know that is not what is going to happen, I do however need to start somewhere. Thanks for the link! I will be reading that one!

An easy fix is to plan your trips to be less than 20 minutes

[shredtherad]

First test is simple, get a hand vacuum pump with a gauge, test the MPS, pull 10 to 15 in Hg and see how long it takes to drop.
Sounds like a cracked diaphragm, runs rich when that happens.

I have this one on the list, I will go down the list and start checking them off.

I don't have the pump/gauge but can pick one up.

I will have to remove the MPS?

[shredtherad]

Watched your video. By video title it says stock so I'm going to roll with fuel injected.

Problem is I think you're looking for an easy agreed upon solution to your problem. You're going to get plenty of opinions or "his fixed my car" responses which might help or might have zero applicability to your problem and will keep you running in circles.

If you're new to 914's, and 50 year old fuel injection, you should probably start familiarizing yourself with the Brad Anders pages and the overview of D-jet fuel injection components and how to troubleshoot them.

https://members.rennlist.com/pbanders/DJetP...tm#troubleshoot

(IMG:style_emoticons/default/welcome.png)

Yup, 73 1.7 with FI.

Of course I am looking for the easy fix (IMG:style_emoticons/default/smile.gif) but know that is not what is going to happen, I do however need to start somewhere. Thanks for the link! I will be reading that one!

An easy fix is to plan your trips to be less than 20 minutes

haha... basically what I have been doing (IMG:style_emoticons/default/smile.gif)

[shredtherad]

First test is simple, get a hand vacuum pump with a gauge, test the MPS, pull 10 to 15 in Hg and see how long it takes to drop.
Sounds like a cracked diaphragm, runs rich when that happens.

Was my first thought, since I had similar symptoms with the 2L D-Jet.

If you're running stock D-Jet, and you have more than say, 75-100k miles on the car, you have no evidence that the diaphragm has ever been replaced, then I'd wager a dollar to every donut that your diaphragm needs to be replaced. The MPS was a very clever design for its time but that diaphragm has a life limit before it will absolutely fatigue.

Mine had those, and other symptoms, and it actually passed the vac test! But when Tangerine pulled it apart to rebuild the crack was obvious. And replacing it transformed the way the car drove.

I like D-Jet, I think it's worth saving. Consider sending your MPS to Chris for a new diaphragm, even if it passes a vac test.

http://www.tangerineracing.com/mpsdiaphragm.htm

Cool, I will do this test. Thanks!

[shredtherad]

First test is simple, get a hand vacuum pump with a gauge, test the MPS, pull 10 to 15 in Hg and see how long it takes to drop.
Sounds like a cracked diaphragm, runs rich when that happens.

Was my first thought, since I had similar symptoms with the 2L D-Jet.

If you're running stock D-Jet, and you have more than say, 75-100k miles on the car, you have no evidence that the diaphragm has ever been replaced, then I'd wager a dollar to every donut that your diaphragm needs to be replaced. The MPS was a very clever design for its time but that diaphragm has a life limit before it will absolutely fatigue.

Mine had those, and other symptoms, and it actually passed the vac test! But when Tangerine pulled it apart to rebuild the crack was obvious. And replacing it transformed the way the car drove.

I like D-Jet, I think it's worth saving. Consider sending your MPS to Chris for a new diaphragm, even if it passes a vac test.

http://www.tangerineracing.com/mpsdiaphragm.htm

https://youtu.be/3lvTXN7d5-8

This seems like a good video/resource

[Lockwodo]

First test is simple, get a hand vacuum pump with a gauge, test the MPS, pull 10 to 15 in Hg and see how long it takes to drop.
Sounds like a cracked diaphragm, runs rich when that happens.

Was my first thought, since I had similar symptoms with the 2L D-Jet.

If you're running stock D-Jet, and you have more than say, 75-100k miles on the car, you have no evidence that the diaphragm has ever been replaced, then I'd wager a dollar to every donut that your diaphragm needs to be replaced. The MPS was a very clever design for its time but that diaphragm has a life limit before it will absolutely fatigue.

Mine had those, and other symptoms, and it actually passed the vac test! But when Tangerine pulled it apart to rebuild the crack was obvious. And replacing it transformed the way the car drove.

I like D-Jet, I think it's worth saving. Consider sending your MPS to Chris for a new diaphragm, even if it passes a vac test.

http://www.tangerineracing.com/mpsdiaphragm.htm

https://youtu.be/3lvTXN7d5-8

This seems like a good video/resource

Yes, that will show you how to test the vacuum integrity and the primary/secondary coil wiring. For troubleshooting MPS and other 914 problems in general, another good resource is the Tech Notebook: https://bowlsby.net/914/Classic/TechNotebook.htm, see Reference Manual section.

[brant]

Can you hear the pump run when it’s acting up and you first turn the key on?

I’ve got a vacuum test gauge , a fuel pressure test gauge and ohm meter if you want to borrow

Brant

[shredtherad]

Can you hear the pump run when it’s acting up and you first turn the key on?

I’ve got a vacuum test gauge , a fuel pressure test gauge and ohm meter if you want to borrow

Brant

Thanks Brant, I will have to replicate the issue and see if the pump is running, from cold start it is running. The issue starts after the car is hot.

Appreciate the offer of the tools. I might take you up on it.

CT