I am still trying to get things together with my 145. It has been starting up then instantly dying, and then not starting again. Pull the plugs and they are all wet and black. The injectors and the rest of the system tests out, but the temp sensor is wonky, and I think it runs the car so rich that it instantly floods the car when starting.

This is a D-jet system. Anyone have a temp sensor out there that they know for a fact works? Any other suggestions? This is getting really old. Can't afford to pay a whole lot for the sensor.
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Sensual Ascetic. Three Volvos. Average age 37 years. No damn cupholders. Good wine.

This is pretty long-winded, so apologies if I'm going over old ground or stating the bleeding obvious :)

When you say that the engine dies instantly, do you mean that it dies the moment the ignition key is released or does it hang on a bit longer? If it dies as soon as the starter motor stops running then you might want to check that the ignition system's ballast resistor is ok. When starting the engine the ballast resistor is by-passed and the ignition coil is provided with full battery voltage. The moment the ignition key is released the ignition system current for the coil is switched through to the ballast resistor. If the resistor is dead, the coil gets no current once the ignition key is released after starting and the engine dies.
If the engine hangs on for a bit, then staggers and dies, the problem isn't the ballast resistor.

In what way is the coolant temperature sensor wonky? The sensor's electrical resistance is designed to vary with the coolant temperature. Eg: At 10 deg C the resistance should be between 3000 and 4500 ohms. At 40 deg C resistance should be between 1000 and 1400 ohms. An "open-circuited" (ie infinite resistance) sensor would certainly make the engine run rich, but I doubt whether it would run so rich as to die completely. If the sensor has short-circuited internally it would run the engine very lean. To test the resistance of the sensor accurately you need to know the temperature of the coolant (or the air temp if the sensor has been removed from the engine) and make sure that the two electrical contacts on the sensor are very clean.
If the sensor is definitely at fault, then ignore the rest of my rambling from here on :)

Next suspect would be the cold start injector, an "extra" fuel injector fitted to the top of the intake manifold near the throttle butterfly. It performs the same function as a choke on a carby, and dumps fuel into the engine when its cold. However! It should only function when the coolant temp is low and only while the starter motor is running. There is an electrical contact on the starter for the cold start injector which provides it with current only while the starter is engaged. The current then travels to a thermal timer which is a temperature controlled device, a bit like the coolant temp sensor, which only allows current to procede on to the cold start injector if the coolant temp is sufficiently low to warrant it. It also has a timing function which limits the time the cold start injector runs for. The cold start injector itself might check out perfectly ok electrically (4.2 ohms resistance at 20 deg C) however it may have failed mechanically. The electrical part of the system might be perfectly ok, but the injector could be stuck open. Best way to check is to remove it from the manifold (easy; couple of screws), unplug the electrical connection, then turn the ignition on and off a half dozen times (without starting the engine) to run the fuel pump and build up fuel pressure in the system. If the cold start injector has a mechanical fault it will leak like a ba*tard and spray fuel. That is not good. They're not repairable so replacement will be required.

Another item which might be at fault is the manifold air pressure (MAP) sensor. Electrically it should have the following values: Resistance in primary winding (terminals 7 and 15 on its socket) approx 90 ohms, resistance in secondary winding (terminals 8 and 10) approx 350 ohms. Even if it is ok electrically, it can fail mechanically. It has a metal diaphragm inside which can split. The guts of the MAP sensor should be absoulutely airtight and a split diaphragm will cause an air leak, messing up the entire function of the sensor. Quick check is to remove the vacuum hose which is connected to it from the intake manifold end and suck on it. It should hold a vaccuum without any leakage.

Other than those areas, it is vaguely possible that the electronic control unit (ECU, processor, computer, etc) has a problem and is stuck in a mode which is telling the fuel injectors to stay open permanently. Very unlikely, but possible.

D-jet is great while its working, but can be a pain in the rear when it acts up.

Good luck.

Have you (or Rob) verified that:

a.) the manifold pressure sensor is within spec

b.) the cold start injector is shuting-off tight.

Yes, I believe so. I have had another friend of Rob's who is really saavy with electrical stuff go through the entire system. Everything is within specs except the temperature sensor.

If this doesn't work, it is time for a single Weber.
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Sensual Ascetic. Three Volvos. Average age 37 years. No damn cupholders. Good wine.

Single Weber?

PLEASE DON'T! I will give you a used temp sensor for free; I'll even pay the postage - if you promise to not install a DGV on your 145.

Best,

Cameron
Rose City

Cameron,

Thaanks for your posting. Believe me, I don't waant to install a Weber on my 145. I just am at the end of my rope in terms of diagnosing what the problem is with the FI. Everything has been scoped and checks out all right, except the temp sensor, and that doesn't seem as if it is really out of kilter.

I live in Minnesota, and this is my winter car. i can't afford to get stranded by this car again when it has been up to -24 below zero even in the city, and driving my 544 with the next to non-existant heat on these salted roads is really a drag.

the temp sensor is coming tomorrow, i am told. I will install it. If that doesn't do the trick, I am out of options. Any suggestions you may have would be appreciated.

I really, really, want to make this work, but don't haave the resources to mess around with it much longer. I have a 122 wagon and my 544 AND a lovely vintage Belgian travel trailer that are my bigger priorities at this time. The 145 is my winter beater.
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Sensual Ascetic. Three Volvos. Average age 37 years. No damn cupholders. Good wine.

Disconnect the sensor and jump (close) the circuit. Depending on tune, injector leakage, and thermal timer operation, it might run fine.

If we're talking about the coolant temp sensor, closing this circuit will tell the ecu that the engine temp is below freezing.

Best,

Cameron
Rose City

I though it was the other way around.
My d-jet engine is mothballed.
Phil S.'s d-jet page says:
"Temp Sensor #2:
ECU harness pin 23 to ground as follows...
Cold motor = roughly 2000 ohms.
Warm motor = well under 1000 ohms. "
I remember discovering how important that connection was one freezing day when the car started and started to drive fine, but would quickly degrade. Several stops later I bumped the wires while attempting to isolated the problem, and got myself home without further incident. I believe I had tried disconneting it altogether, and that made it worse. The harness was corroded and finding the small female connectors at that time was a problem, so I soldered the wires to the sensor.

I live in Minnesota. Will the extreme cold here affect whether this will work or not?
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Sensual Ascetic. Three Volvos. Average age 37 years. No damn cupholders. Good wine.

I wouldn't bother with a used one - these don't last forever, and a used one will only reproduce your current symptoms that much sooner. They're available new for around $20; cross check the Bosch part number from the sensor with your local import parts supplier.

It's worth paying for a new one of these. Broken one = immobile car.

Have you confirmed that the fuel pressure is correct?

Best,

Cameron
Rose City

I didn't realize they were so affordable, or even still available. Thank you.

I've been told the pressure regulator is fine.
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Sensual Ascetic. Three Volvos. Average age 37 years. No damn cupholders. Good wine.