I notice 3 connectors - two to micro switches and one to the capstan position sensor. Please find out which on is most likely the culprit and if it can be bypast for testing somehow ( or tested some how )

 

The micro switch next to the capstan is the enrichment switch....easy check, just push it while the car idles and the RPM's should come up slightly, working or not this shouldn't cause your problem. The capstan position sensor should tell the ECU to pulse the injectors (sorry if my terminology is wrong) as it's rotated in conjunction with the butterflys letting more air in....this IMO would cause your problem if it's not sending a signal.
The D-Jetronic Throttle Switch
http://www.remschel.com/TPS.htm

 

Throttle Position Sensor Testing
It's important to remember that even if the componant checks fine (TPS) all it's connectors and wires must be good from point A (TPS) to point B (ECU) to point C (injector harness).

 

Not sure if I understand the question.

But, anyway, what are the wire colors?


Cheers
DD

 

This is such a long hread that you probably missed posts 21-24 where the TPS has already be checked. :-)




No offense intended but just to keep things less confusing it might be a good idea to avoid any references and links to the early style throttle position *switch*. It operates entirely differently than the throttle position *sensor* used on the car in question



Much better :-)


Cheers
DD

 

Apparently it is a known fault with this type of fuel injection, that the hot wire air flow sensor dies. The car starts without referencing the sensor, and will idle using the last good settings it had, but as soon as the throttle is moved, it dies.
Hope this helps.
Let us know the results.

 

Good thought the car in question doesn't use an air flow sensor


Cheers
DD

 

Hi Doug, owner says car has injectors, what does it use to measure airflow?
Is it a flap system, similar to series 3 XJ.

 

fred, I _think_ this is interpreted by the Throttle Position Sensor and not actually measured like the newer cars with the MAF sensor. I have checked at the TPS but not certain how (which wires) at the ECU and the TPS was reading right in range and no spikes nor drops detected thru the full range of motion.

 

No air flow metering or measurement per se; no air flow meter.

The system primarily relies on the throttle position sensor and the barometric pressure sensor in the ECU

Cheers
DD

 

Anyone know which pins in the ecu plug are to the TPS? I want to make certain I have a signal all the way to the ecu. If I do, then it looks likemy next favor from the forum is to see if I may borrow an ecu for one day - iwillpay for shipping both ways....

M.

 

This is the UK/ Australian markets' EECU pins:

Pin number:
(Pin nos. read from Right to Left as you look at them in the ECU, opposite to normal writing) :


Bottom row:

1 = not used.
2 = EARTH
3 = not used
4 = not used
5 = Coolant temp sensor LH thermo housing
6 = not used
7 = TPS (yellow/white) This carries the wiper signal from the TPS so voltage should vary with throttle position.

8 = Connects with pin (9) and then goes to pin 4 of the resistor pack, via 2 connector splices.
9 = see 8 above
10 = not used
11 = to pin (10) of resistor pack
12 = to pin (7) of resistor pack
13 = Connects with pin (14) and then goes to pin (1) of resistor pack, via 2 connector splices.
14 = see 13 above
15 = Orange wire to pin (85) of the fuel pump relay (Earth of that relay).
16 = EARTH
17 = Start inhibit switch. Mostly known as the “neutral start switch”. The other side of the inhibit switch goes to pin (W1) of starter relay.
18 = the “shielded” wire from the ignition module. The central core (thin wire) connects here. The “shielding” is earthed at this area also.

Top row:

19 = TPS (Yellow/Black) and picking up a splice that is the 2nd wire to the coolant temp sensor in the LH thermo housing.
20 = TPS (Yellow/Pink) and picking up a splice that goes to the air temp sensor (one side). This is the 5 volt feed to the TPS and other sensors.

21 = Air temp sensor 2nd wire.
22 = Power (12v) to ALL injectors, via 4 splices. This power is supplied by pin (87) of the main relay, and the terminal (22) of the ECU is actually “power IN” to the ECU.
23 = not used
24 = not used
25 = not used
26 = To pin C1/C4 of starter relay.
27 = Pin (6) of resistor pack with a splice of pin (28).
28 = See above (27)
29 = Pin (8) of resistor pack.
30 = Pin (5) of resistor pack.
31 = Pin (3) of resistor pack with a splice of pin (32).
32 = See above (31).
33 = not used.
34 = EARTH
35 = EARTH

 

Thanks Greg!

 

I cannot believe that I am still not successful with this.... this car is not very friendly to work on at all!

 

Have you got your USB scope and then checked that you have widening pulses at the injectors when you touch the throttle? It will save a lot of fumbling in the dark to establish this one fact.

 

USB scope came in just before I got called out of town. :-( the hookup should just be between the two wires to the injector (right?). I was go

 

............
Oh Dear! Should we have told him not to connect the scope to the 3 Phase?

 

Not getting very far as I have been out of the country. Back to trying to figure out this USB scope. (funny steve - I did not realize my last post was a _bit_ cut short (no pun intended)). Still have this V12 yard ornament - electronics has NEVER been my strong suit. Anyone live near Charlotte, NC that can help?

 

In the meantime, try this simplified version: Connect a 12V (may need to go to 6V) bulb at one of the injector connectors instead of the injector. When idling it should glow dimly. If it goes out promptly when you toch the pedal we are one important step further. If it just stays equally dim until shutting down we have still learned something. If it at least momentarily glows a bit brighter we have also learned something useful.

 

Will try if it EVER stops raining here! It has been raining for 3 weeks straight - thinking about turning the car over and making it a boat....