Hi guys, Chris from New Zealand here....finally bought myself a 914! Shes a '73 2.0 with original FI. Had her about a week, after standing for 8 years.

Previous owner spent some time and money getting her on the road as part of the sale to me, but still a bit of work to be done! I'll try and attach a picture.

Took her for a shakedown run today for about 3 hours but then she started coughing and spluttering then stalled at about 60mph. Coasted to a halt, ignition on/off and away she went again for about half an hour.. Same thing again, ignition on/off and all was well for another 20 min.. This went on and on and the intervals between spluttering and stalling got more frequent until i just about made it home.

Felt like fuel rather than electrical... Could it be the fuel pump, or any other ideas?

I have a feeling I'll be using the forum quite a bit

Nice to meet everyone!
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Welcome, and that's a pretty car! I would first look to vapor lock. If she runs great when you start her up cold today, that could be the problem.

There are many other possibilities but that is the first I would look at. If it runs badly cold today, then it is not the issue and we can look elsewhere.

Thanks dude! Well the last 3 or 4 days of cold start she coughs and splutters until thouroughly warmed up, but ok after that.. These drives have only been short distances with no issues.. The stalling etc only happened today after the 3 hour drive. Ill see how she runs tomorrow morning.

Congratulations and welcome to our community!

Beautiful car. Welcome to the World

You may want to start learning about D-Jet. It's an old but reliable FI system, but like any other system the parts all have to be serviced. If the FI is 'original,' as in hasn't been maintained, you'll definitely want to go through it. Good reading: https://members.rennlist.com/pbanders/DJetParts.htm

For the issue you had specifically I'd start checking to make sure all connections are secure. That includes the ground points on the engine and the relays and connections at relay board assuming it is fuel delivery and not electrical. Could also be blocked filter or line somewhere along the fuel path.

I've never experienced vapor lock as far as I know (my fuel pump was already moved from stock location) -- can that happen while cruising? I would think the constant flow of fuel would not allow it to "boil."

Trust you instincts. The Djet is not a very complicated system compared to modern FIs and not a lot of components. Invest in a fuel pressure gauge and see what the fuel pressure is. Keep the gage installed and confirm the pressure when it acting up. I tape my gage to the back window so I can see it while test driving. You get the idea. Once you confirm your fuel delivery you can move on to another system, or fix your findings...best regards...keep us post on your findings

the attachment point on the rail for the fuel pressure guage makes Rfinegans suggestion real easy.

The rough start suggests to me your aux air valve may be misbehaving. Since it starts fine after it is warm it could be that or the FI cht sensor. If you crack the throttle on a cold start does it idle fine at 1400ish rpm? If so, likely to be the aux air valve. If it still kinda runs like crap I would check the cht sensor (it enrichens the mix when cold).

I think you are going to have to go for another long drive and see if it does the same thing. Maybe run some injector cleaner through it while you are at it.

And before you do anything else, check those plugs to see if it is running lean. If you have low fuel pressure or a pile of other issues, you want to make sure you aren't melting your engine.

What you are describing sounds like vapor lock to me as well but any car that sits that long needs a full inspection of EVERYTHING.
The first inspection I'd do is gas tank internals. 8 years is a LONG time.
I don't know what New Zealand fuel is like but here in the USA the tank would be "poisoned" and require either replacement or massive cleaning. Our fuel goes south after 6 months. 8 years would turn it into varnish...

I've got a 75 that has been dormant since 1989.
It's been "standing" for 34 years!

I'm doing what I call a "resurrection" to it. It is the longest dead time car I've ever done.
You solve all the problems you can find and drive it until something else shows up.
You fix and drive again. Lather/rinse/repeat.

One of the initial tasks is compete replacement/ restoration of the fuel system.
My car still has the hard plastic fuel lines that Porsche used 50 years ago.
It's getting all new steel lines before returning to service.

A fire extinguisher will be a passenger for the first 500+ miles, even with the new fuel system in place.
The ONLY times I've ever needed an extinguisher is when one wasn't available.
If you have it with you, you will not have a fire that requires it.

The brake hydraulic system is another system that requires full rebuild after 50 years.
ALL rubber-based parts are being replaced before road use. 8 years non-use does not kill this system like it does a fuel system, but your system is 50 years old this year and no hydraulic system lasts half a century.

Beautiful car, love the color.

Could be blockage of the screen in the fuel tank, Debris blocks the flow when running then after it shuts off, drifts away from the screen.

You can take off the filler neck and look down in there, Not a real big deal to pull the tank and clean/replace the fuel sock.

also can check if the rubber lines have a kink in them.

greeting from fellow NZ 914 owner .
As beatnavy mentioned check the grounds, connections, relays etc as it could be electrical,if it all looks ok check plugs ,leads ,cap,points and plugs ,could be something simple like a dying coil or points out of adjustment/or just worn out.
Reset / check valve clearances then start it up and check timing if you have a stable idle otherwise you need to make sure your aux air valve is working,you can test this by diconnecting the power wire and if it still runs the same the valve is stuck and not opening.
See how you go ,you can email me for a chat anytime ,like to keep up with NZ owners and chat ,cheers.
Oh and forgot to mention ,real nice looking car .

Thanks Porschetub! where are you based?

This was Alistair Moffats car in Auckland. He's done a fair bit of work to get ot on the road, mostly what needed to be done to pass a WoF and get it drivable, so brakes, clutch, gear shift springs, bushes, some FI hoses etc etc... It drives really well. feels tight and responsive, just the stalling issue to report after a drive from Auck to Mt Maunganui and back in the same day... The usual rattles and squeeks prevail, but nothing that some online shopping at Auto Altanta cant fix! (where do you go for your parts?).

Started ok this morning.. bit of a flutter, but a boot full got it idling.. Seems to idle high at around 1200/1400 rpm.

Thanks StarBear!!!

Thanks emeryGT... Started ok this morning.. bit of a flutter, but a boot full got it idling.. Seems to idle high at around 1200/1400 rpm though. Havent taken it for a ride yet to confirm the same issue. A few members have suggest vapour lock, but also i think i'll start to check all of the connections first to eliminate the most obvious/easiest to check!

Thanks BeatNavy! Yes, i think checking all of the connections that yourself and others have mentioned will be the best place to start...

Thanks rfinegan!! Thats a great idea! I think outside of checking loose connections and simple to do stuff, that might be a good place to start.

Yes, starts first time after the initial morning start and does seem to idle very high at around 1400rpm. Some great thoughts there.. Is there a way to actually check the aux air valve / cht sensor?

I think ill check all connections, plugs, distributor first to see if anything obvious.

Anywhere you go to get your spare parts other than Auto Atlanta?

Thanks Technic!

The guy i bought it from did a lot of work to get it road worthy such as clutch, brakes, FI hoses etc etc etc, so it drives well apart form the spluttering and stalling.

Sounds like you've got a bigger job ahead of you than me!!!

1400 is where it should idle at cold start.

Let's take it slow and not break anything. These are 50 year old fuel injection.cars. they don't behave like today's cars.

I suspect yours is actually in really good shape.

Cool, thanks! I'll start with checking connections etc then go from there... So far the main comments are possible CHT sensor failure or Aux Air Valve failure..

At cold start (20 c) it should jump up to 12-1400 rpm. As it warms it will rise to 1400 but shouldn't go higher. That is the aux air valve. As the filament in the aav heats it will bring the idle down. As the heads heat the sensor the ECU uses to enrich the air fuel ratio will eventually tell the ECU to knock it off. At this point the idle should be about 850. This can take a long long time in cold temps. Temps less than 20c.

The system the type 4 uses to control airflow over the oil cooler and heads is really interesting and important. Besides insuring that you are not running lean, you need to make sure that is working as intended. Do you have a Chilton's or clymers manual?

Just went out for a 30min spin and the idle etc seems to line up as per your comments above.

The first 10 minutes of the drive it was coughing and spluttering, no power etc.. But after about 15 minutes of warm up that went away and it ran fine.

This is how it was yesterday, but on an extended run (a 3 hour drive) with more time is when it stalled a number of times.

No, dont have either of those manuals..

You need to get the Haynes manual for the 914 4. It will be difficult to identify the parts you need to find without it.

It sounds like that aux air is working? Was your idle high at start and then decreased over time?

Hello and very nice car, your problem for the long drive issue is fuel starvation. There is dirt at the bottom of the fuel tank, material is building up on the fuel sock as you drive, due to the constant high pressure.
Clean fuel lines, tank and replace the filter, I like to reverse polarity on the fuel pump to back flush it.

When you get the lines clean, hunting down D-Jet problems will be easier to fix.

That is a possibility, but I would save that for after some of the easier stuff is ruled out.

With the tank empty, you can look in the tank (flashlight) and see the condition of the fuel sock. Sucked flat, copious amount of rust in the tank bottom and fuel well? Remove the tank, clean it and replace the sock. I would plan on replacing the fuel filter as well. And any old hoses.

flashlight , look in gas tank ,replace fuel filter....OLD Car Blues

Skip replacing the sock filter in the tank and place a line filter outside the tank where it can be observed and serviced.

As the pump creates a vacuum the fouled sock sucks flat, fuel flow is reduced or stops. You can put 10 filters on the supply line but the issue remains. The first one in line will get fouled with tank debris. Cleaning the tank itself and replacing the sock removes 2 issue items. Most socks are decades old and rusted tanks add to the problem. Tank socks cost about $5.50. You can’t buy filters for that. Then there’s the joy of replacing or cleaning the first stand alone filter on a regular basis. No thanks.

I'am based in Nelson bays in a 'one horse' town over the bay called Motueka ,moved here a couple of yrs ago .
I have bought parts from mainly from the west coast of the US as it keeps the crazy shipping cost a bit less crazy ,I can email you my favourites if you like .
Sellers on here are great also as there prices are generally very keen and NEVER had an issue with quality .
Sounds like your cold idle is in the ballpark so your AAR must be working ,could be an air leak to fix or an adjustment of the air screw,best to check your timing before doing this as it could be over- advanced or the distributor is a bit gummed up which is very common with 205 number units..
Sounds like a bit already been done so thats a step ahead in terms of labour ,time and $$$.
Included a pic of my NZ new car ,cheers.
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Pull tank
Replace fuel sock and all rubber lines under tank.
Dump all fuel in tank
Wash tank with laquer thinner or paint thinner
Fill, shake, dump, repeat.
Dump out the filler area, it’s bigger.
Repeat until no debris comes out.

Then put it all back together with a new sock.
Replace fuel filter.
Make sure fuel filter is between the tank and the pump.
Make sure the line that feeds the fuel pump is the line with the sock at the tank.


Rich

Wow, you guys really want to pull this poor guys tank. This happened once. After 3 hours of driving. Lots of little easy things to check on before we go replacing every part of the fuel system.

So, back to the first issue to solve...
I suspect the fi cht might be disconnected/not working/lacking the weird 1 year only inline resistor. Does it start right up and then after a couple of seconds run rough at cold start, or is it immediate?

How long did the car sit with bad fuel in it?
Todays fuel turns into honey, then gets hard.

Nah - people love the shotgun approach rather than logical, methodical troubleshooting I think it comes down to a belief that by swapping parts your doing something.

From OP 1st post there are probably a couple separate issues going on.

Not sure why so many have jumped to the assumption that it’s a fuel problem. Ignition issues have a surprising way of seeming to be fuel issues and vice versa.

Well funnily enough, i went over to the guys house i bought the car off and he has a rebuilt AAR valve! So ill put that in next weekend and see if that fixes the isue..

Thanks MG! all good advice for the newbie!!!

Thanks Rhod!! if and when the tanks comes out, may as well change the filter and poss the pump, seeing as its 50 years old i reckon!

Thats good advice, cheers dude!

Ahhh Moteka eh! Never been, but know of it... Thanks for the advice.. Alistair has given me a rebuilt AAR, so may as well install in next weekend, see if that helps. One thing at a time!!

Is your car a 6?

Thanks for the directions, will need these if/when i pull the tank!. Well i have found a rebuilt AAR which ill throw in next weekend, se if that fix's it, if not then perhaps the tank and replace the filter while its out too

And thanks for your email re where to buy from Dean, really appreciated! Just bought a rear window mastic kit to reseal the glass as its started to rattle from 914Rubber after my trip to Tauranga and back...

If the car idles after warm, and idles at 1300ish when cold, your aar is working great. Save the "rebuilt" one for the Future. Rebuilding one isn't exactly normal (check the threads on that) so I am a little suspect anyway.

You can test your aar function buy pulling and blocking the hose from the air filter housing to the aar. If the car is warm, it shouldn't change anything. If the car is cold the idle should drop and if cold enough the car should stall. There are 3 bits to the cold start.
1 the aar which bumps up the idle speed by letting extra air into the plenum.
2 the ECU using a cylinder head temp sensor to cause enrichment of the air fuel ratio
3 the csv which is an injector mounted in the plenum and gives you a shot of extra fuel at start (the timing and conditions necessary for this are debated endlessly).

Rough running at the start and then recovery with poor performance till warm makes me lean toward an issue with 2.

My $.02 (US). It's not vapor lock. If it was, in my experience, it wouldn't restart immediately. You'd have to wait til it cooled down to get started again. I think the comments about rust in the tank and clogging the sock fit the symptoms perfectly. The tank isn't hard to pull if there's not much gas in there. Don't think of it as a last resort. Can't help with the idle and rough running, that's for the experts. Good luck and....

fits the bill. good place to start.
my 14 is an L jet so can't help with D jet. if its not bad fuel, dirty tank then mr. @emerygt350 is probably on track with what he is speaking of?

a quarter of a century ago i did pick up a bad tank of fuel. water in the petrol.
car almost refused to run. when it did, misfires, spluttering, backfires. etc. had to flush the tank and system. injectors esp do not like gunk if it manages to get past the filters. even the smallest particles or impurities. to note it did not come good during that episode as your car is appearing to after you switch off. tends to make me think the fliter or filters if more have been fitted are blocking up then after switch off doing the classic temporary clear as the much floats back off the filter surface (for a little while).

you would only get vapor lock if the pump is in its stock location under the engine attached to the right hand chassis member behind the cabin. and it only happens after a hot shut down and not while you are on the move. it won't be that.


good luck with it.


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and hello from across the tasman.
looks like you picked up a sweet little 14.
lots of interesting cars in NZ, most kiwis i have run into are petrol heads of the highest order and practical people.

Thanks! Looks easy to test the AAR.. The other comments also point to the CHT sensor. I think their quite cheap, but of course it has to come from the USA, so theres a few weeks for that! If the AAR tests ok, maybe worth just puting the CHT sensor on order...

Thanks Marc! Unfortunately my tanks 3/4 full! Ill test the AAR first this weekend, and if that tests ok, ill probably order a CHT sensor as its going to take me a while to get through all of that fuel, especially as it stalls so i cant drive that far to use the fuel up!

Thanks Wonki! I think after ive tried the sensors, the tank will be the next stop...

Hmmm. That cht for the fi is nla if I remember correctly. I could be wrong. For 1973 the cht also has an inline resistor (also no longer available) that was a stop gap before they came out with a new computer for the 2.0

You should test the cht first, easy to do with a multimeter.

Google pbanders d-jet and you will find all the information a person might need (resistance at cold etc).

If the resistor is missing, you can simply make your own (I had to on mine).

You mean the link I provided in the 5th post?

https://members.rennlist.com/pbanders/DJetParts.htm

If you plan on troubleshooting and working on this car yourself, I strongly recommend you start getting familiar with D-Jet theory as well as its specific components.

Also, Chris, don't feel obligated to thank / respond to each individual post separately. It's thoughtful, but it also kind of makes the thread longer and harder to follow at some point.

All good, and good luck!

https://members.rennlist.com/pbanders/