KE Jetronic Manual 87 Testarossa

This link:

https://www.dropbox.com/s/18bidr3sgbofytb/Workshop Manual Testarossa Supplement Catalytic Converter D61-D106.pdf?dl=0

will get you a pdf copy of the TR WSM section covering US version F113A040 engine TR (KE-Jet with Lambda). If you are dealing with an F113B engine TR (KE-Jet without Lambda) it will be very similar, but without the "with Lambda" stuff. Never seen any schematic information for what is inside the TR KE-Jet injection ECUs (of either type). If it is a F113B engine TR, do you have a copy of the 459/86 Wiring Diagram?

This was one of Bosch's general publication about KE-Jetronic:

https://www.dropbox.com/s/26bbwi0fkl592zd/Bosch KE-Jetronic Manual.pdf?dl=0

but every manufacturer has slightly different details in their implementation.

 

great steve, you are always very helpfull

 

First, please confirm if you have K-Jet or KE-Jet.(you've written both in your posts).

Also, what is the engine family marking on the engine block above cylinder #6 -- should be something like F113A000 or F113A040 or F113B000, etc.?

 

OK, KE-Jet without Lambda (F113B or F113B000) -- the injection ECUs get their +12V power from the Protection Relay in the triangular black box over the RR wheel well (not the Tachometric Relay). The food chain is:

1, There is a GR (yellow-red) wire connected to the same large post on the Starter Solenoid as the big +12V battery cable,
2. Goes thru the large round C12 connector on the triangular black box,
3. Goes to terminal 30 of the Protection Relay
4. Thru the 10A fuse of the Protection Relay
5. Comes out terminal 87 of the Protection Relay (when the Protection Relay is closed -- which it should be whenever the starter motor is cranking or the engine is running. A signal from the Tachometric Relay closes the Protection Relay, but that same signal runs the fuel pump relays = if the engine will run at all, even badly = the Tachometric Relay is OK).
6. The +12V power goes out the C12 connector to pin 1 of both injection ECUs,
7. Then it goes on to the throttle idle microswitch and the red wire at the water thermoswitch.

Consequently, the best thing to do is measure the voltage on the red wire at the water thermoswitch when the engine is running, the starter motor is cranking, or you have "fooled" the Tachometric Relay to close (which closes the fuel pump relays and the Protection Relay) as per these instructions:

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If the red wire at the water thermoswitch is +12V (when the engine is running, the starter motor is cranking, or you have "fooled" the Tachometric Relay to close) = the Protection Relay system is working and the injection ECUs have +12V power (and any runability problem is something else - like the GR wire being broken from its loop terminal at the starter terminal, a bad connection in C12, a blown 10A fuse).

If the red wire at the water thermoswitch is not +12V (when the engine is running, the starter motor is cranking, or you have "fooled" the Tachometric Relay to close) = the Protection Relay system is not working and you have to determine why (it may be something other than the Protection Relay itself).

Chew on some that and give a shout back for what you find/measure. Unfortunately, if the car was tweaked up warm with the Protection Relay system not working, it will have to be retweaked up warm once the Protection Relay system is working.

PS Early Protection Relays had the 10A fuse built inside it so it wasn't replaceable/inspectable. I think a 1987 should be late enough to use the later style Protection Relay with the accessible/replaceable 10A fuse on the outside, but just wanted to mention this difference just in case.

 

I put an edit in the wrong place- it should be:

If the red wire at the water thermoswitch is +12V (when the engine is running, the starter motor is cranking, or you have "fooled" the Tachometric Relay to close) = the Protection Relay system is working and the injection ECUs have +12V power (and any runability problem is something else).

If the red wire at the water thermoswitch is not +12V (when the engine is running, the starter motor is cranking, or you have "fooled" the Tachometric Relay to close) = the Protection Relay system is not working and you have to determine why (it may be something other than the Protection Relay itself - like the GR wire being broken from its loop terminal at the starter terminal, a bad connection in C12, a blown 10A fuse, etc.).

 

Very good, but can you be more specific:

1. The Protection Relay itself was bad (and all else in the Protection Relay system was OK)

or

2. Some other problem in the Protection Relay system was preventing the Protection Relay from working? (and please describe what the problem was)