I have a stock 1973 2.0 with djet with approximately 30,000 miles on a brand new motor.

BRAND NEW:
- Fuel lines
- Fuel injector seals
- Correct CHT temp sensor(0 280 130 017)
- Spark plugs
- Fuel filter
- Trigger Contacts


Things i've checked:
- Fuel pressure set at 29
- No vacuum leaks(new vac lines)
- Timing is set
- Valve adjustment
- Continuity between the CHT and the ECU
- Timing is set
- Plumbing to CSV is disconnected
- Correct MPS that holds vacuum

I am wondering if it could be a series of malfunctioned injectors or something that I haven't overlooked. Whats the best way to bench test injectors to check for rate and spray pattern?


When I start the car when its cold, the exhaust spews a black liquid for a couple of minutes then it goes away after its warmed up. Attached is an image of the black liquid.

No one knows anything?

Do you have the correct '73 only system? Do all the numbers match between the ECU, CHT Sensor, and MAP sensor? Do you have the correct 270 ohm resistor inline to the CHT sensor? Have you adjusted the knob on the ECU when warm to set the idle mixture? How do the grounds look on the case?

Just a couple questions for ya...

I'd start looking at the thermotime switch that controls the CSV. I'm not sure how they default when they start to go bad, but it really sounds like it's that kind of issue to me. I agree that you should adjust the idle mixture when it's warm (after the black liquid stops spitting out the exhaust), but I really think your problem is either in the cold start valve or the thermotime switch that controls it. I'm not the expert on this subject, so I'll refer you to someone who is.
http://members.rennlist.com/pbanders/
This website has all kinds (maybe too much) information on problems, symtoms, and diagnostic procedures for the D-Jet system. If you are completely overwhelmed by that, you could try unplugging the electronic connector to the cold start valve and see what it does. It probably won't start as easy, but when it does, if it doesn't shoot black liquid, you know for sure that it's in that system somewhere. Hope that helps.
Mark D.

Sounds like he has already gone over the Anders site.(thread title) And IIRC, thecold start valve only comes on in near freezing temps and only stays on for about 8 seconds. After that, it has no purpose. As far as I know, there is no thermo time switch for the CSV. It is just the computer that controls it. If there is one, where is it located? Pics?

I live in climate where the CSV is not needed, so its disconnected at this moment. I have studied Paul's site extensively, but have not found the problem YET. I've called all the local bug shops and they seem to tell me what I already know. I have a feeling its going to cost $800 worth of injectors, but I want to be certain before I make such a payment.

Has anyone bench tested these injectors? If so, can I bench test all 4 at once?

I think you should have your MPS checked and verified that it goes with your ECU.

A bad or leaking MPS will without a doubt cause rich running.

The thermotime switch is what tells the computer that it's cold enough to fire the cold start valve. If it were bad, it could be sending a signal to fire at a higher temperature than it should, and possibly for longer than it should. The switch is screwed into the block just inside of the #4 cylinder, by the distributor. It's got a wire that plugs into it from the injection loom.
Although that doesn't really matter, because scooters says that it's unplugged at the moment. If it runs with proper fuel mixture after it's warmed up, I would still consider it a control issue. If you had sticky injectors or something, it would run crappy all the time. I would do really hardcore diagnostics before I jumped to spending 800 bucks on injectors. I know I don't have that kind of money to throw around.
Again, I'm not the expert, but lemme throw something out there. Do you have the ballast resistor on the CHT that Paul mentions right here.
http://members.rennlist.com/pbanders/DJetParts.htm
That directly affects the temperature signal that it sends to the computer, so it may be something to check out. I've never dealt with that vintage 914, so I don't know, but I ran across it when doing research for you and thought I'd bring it up. BTW, where in So Cal are you?
Mark D.

What is the oil level? Is it over filled? Does the car sit at an angle down or up which can cause the oil to weep past the rings into the head area and when you start it, the oil gets blown out. We had a problem like this and added a removable drain plug in the bottom of the muffler(s) to empty out oil accumulation periodically.

What you are seeing, is most likely water and carbon from the exhaust. The carbon is from running too rich, and the water is one of the by-products of combustion. As to spending $800 on injectors, they can be had for far less than that. You can get replacement ones for $50 each.

Mark, I know what part you are talkin about now. I almost forgot about it since it hides under the air distribution box. I have never heard of those goin out. I even had mine disconnected without knowing for a while and it made no difference. Also, his CSV wont make it run richer if it has no fuel supply to add into the A/F mixture.

As to bad injectors, do the spray test to see if any leak, but if it seems to run good after it spits out carbon then I wouldn't suspect injectors. My car does the same black crap on the ground when cold thing, but its usually due to the air the engine is breathing in. Almost all cars get water out the tailpipe when they are warming up. If you had been running rich before, the stuff on the ground is just from the carbon build up going into the water vapor and out the exhaust. Not a big deal, just leaves spots on the ground.

it's carbon + water....i've got the same thing on my car, but i set it a little rich to run cooler.

Sounds like you've done everything you should. My suggestion here is to get hold of the VW1218 tester - I believe Pelican rents it. It can check out your ECU to determine if there's a problem, as well as check out the entire system, including wiring harness faults. You said your CSV is not connected - do you mean it's not ELECTRICALLY connected, or not connected to a fuel source, or both? If just electrically disconnected, it still could be leaky and dumping fuel. You also may have a stuck injector, as others have suggested, it's worth a check.

Are you sure it's really rich? Like Dagmar said, though you get black gook when you start, that could be just condensation washing out soot from previous rich running conditions. Have you tested your warmed-up idle CO?

Lastly, though your MPS is the right part number and holds vacuum, has it been tampered with ("adjusted")? Is the epoxy seal on the end cap intact? If not, all bets are off as to whether it's set correctly.

Condensation spitting out. The CSV only activates while CRANKING. After the engine starts and you let go of the ignition key, the CSV stops working. And yes, it only works in cold temps.

Running rich is also caused by low voltage.

it is not likely that all 4 injectors would go bad at teh same time. I recomend a comparative test. check flow on each injector. observe teh spray pattern and volume over defined time. readd your spark plugs . are they teh same? these checks should only take about 30 minutes max

BMXerror - I live in Whittier at the top of Beach blvd.

Paul -
The MPS, harness, and computer part numbers are correct and all work with each other. The MPS holds vacuum and it does respond when I give it vacuum. MY dad replaced the MPS about The MPS has never been tampered with and the factory epoxy is still covering the "adjustment screw"

The car averages at about 15-16 MPG.

I have the correct CHT sensor(0 280 130 017) with the 270 ohm resistor and there is continuity between the sensor and the ECU.

The fuel line to the CSV is disconnected, but its connected electrically to the harness.

I thought the thermo time switch only operates when starting, so regaurdless if it is shorted, it doesnt help me because my problem is the rich mixture after warmup. Plus the CSV works in conjuction with the thermo time switch, but since my CSV is never needed, its disconnected from fuel.

Aircoolednut - You mentioned that low voltage can cause a rich mixture. I had alternator problems for a while but those have been solved.

Banger - I know you can find rebuilt injectors for less than 50 bucks a pop, but I would rather not hassle with silly rebuilt units.

John Rogers - The car never sits at an angle, so I dont think this is the problem. The carbon liquid buildup looks much more similar to water than oil. The oil level is always at the correct level as I check it every week or so.

Your mileage sucks. Is this regular old 2.0L? If it is, then you're definitely running rich. What's your idle CO?

Here's one more thing to consider - your trigger contact points in the base of the dizzy. If they're totally buggered, that could be another potential problem site.

I know it's hard to believe, but basic fuel metering of D-Jet is pretty simple. The ECU just needs four inputs - the intake air temp and the head temp, the speed input from the trigger contact points, and the MPS signal from the intake manifold vacuum. If all your components are working correctly (ECU, TS1, TS2, MPS, and TC's), and the injectors aren't jammed shut or open, and the fuel pressure is correct, you should be awfully damn close to the correct mixture.

The "alternator problems" comment has me thinking - did you have an overvoltage situation? You could have blown your ECU. You can get a spare ECU (especially the 037 ones) from ebay for cheap. The VW1218 tester can determine if the ECU is good or bad.

The mileage hurts me the most because its the only running car I have right now. When I start it up, the idle is at 2000, but after 5 minutes it idles itself down to 1100. I know it should be in the 950 range but the rich mixture is causing it to idle high.

I installed a set of brand new Bosch trigger points about 6 months ago because the contacts on the old one was worn out causing the car to cut out under acceleration.

Automotive technology from 1968 isn't that hard, but certainly takes time.

I was running rich before the alternator issue, so I doubt the ECU blew out. I have an extra ECU that I plugged in and ran for a while but it still ran rich.

It would be great to get a hold of that VW1218 tester, but Pelican says they no longer have the tester.