Help Please! - My Testarossa starts for about a second then stops

Check out ALL the electrical connections in the engine bay. Unplug/Replug them including the black boxes under the right rear fender area. Also check the fuse panel up in the trunk. Verify that the fuel pumps run by "jumping" the relays as shown in the shop manual. Your problem does sound like an electrical issue. Hopefully our "Testarossa Knight in Shining Armor" will chime in and help....

 

Could it be as simple as a bad battery?

When the car shuts down:

Any warning lights on the dash?
Does the dash stay on?
Any fuel smell?

Does it make a difference if you rev the motor?

If this were a porsche, I would wonderabout a coldstart solenoid...But its a ferrari.. ;(

 

Moderator -- Could you please merge the two duplicate threads with this same title.

gfrench -- Welcome to FChat, but why is this your first post!

Can you please confirm what engine family is used in your TR (it's shown on top of cyl #6 in a small rectangular area, and is something like F113B, F113A, F113A046, etc.) as this may affect what "electrical" things need to be checked.
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So, it came back from a Graypaul service with 0 fuel and an electrical problem - tell them to collect the car from you and sort the problem free of charge in my opinion...

 

gfrench -- another question that would help in the diagnosis -- during the starter cranking and brief running period does the tach work?

 

It sounds like it is starting off of the spray from the cold start valve, but then stops because there is no fuel being injected from fuel injectors.

One common problem is the relay that supplys power to the fuel injection lambda control units goes bad. It is located inside the black metal box on top of the rr. inner fender panel. The relay is the one that has a fuse built into it. You could just the 30 and 87 connections of the relay and see if the car will run.

Brian

 

You should probably first try to isolate which system ignition, fuel, or electrical is causing the problem.
The first step for me would be to make sure there is spark by hooking-up a timing light while you crank/run it to test for spark.
If yes, then check for fuel. An easy way to check for the absence of fuel would be to temporarily hook-up a cold start injector (TR has 2?) with a momentary contact switch. Then pulse the switch after it fires--if it somewhat keeps running then there is probably a fuel delivery problem. The next step might be to check the fuel pump circuit to make sure it is getting current. Then fuel pressure...

Best of luck to you,
Mark

 

I've heard via PM from gfrench that it's a F113B TR -- i.e., KE-Jet without Lambda.

The guys have already made some good suggestions about who/what the culprit might be, and I agree with Mark that confirming that you've got spark on both banks during the cranking and the brief running period is the first step needed before delving into the KE-Jet injection electrical system. (If the tach works, this would be a good sign that it's not a spark problem, but confirming the spark presence/absence directly on both banks would be best.)

If spark is not the issue, there are two voltage measurement that can be very useful in deciding what to do next on a KE-Jet TR (leave everything plugged in):

1. Verify what the "protection" relay C in the black triangular box is doing (or not doing) per Brian's suggestion. See post #6 in this thread:

http://ferrarichat.com/forum/showthread.php?t=70680

You want to measure the voltage between the red wire going to the coolant thermoswitch (item 20) and ground during starter cranking and when you release the key to the "run" position.

2. Verify what the Tachometric relay is doing (or not doing). You want to measure the voltage between the Z (violet) wire in the "x" white connector and ground during starter cranking and when you release the key to the "run" position. These jpegs show where you can most easily access this violet wire.

Consequently, your task is to answer these 4 questions:

1. What is the voltage on the red wire (relative to ground) during starter cranking? (0V or +12V?)

2. What is the voltage on the red wire (relative to ground) when you release the key to the "run" position? (0V or +12V?)

3. What is the voltage on the violet wire (relative to ground) during starter cranking? (0V or +12V?)

4. What is the voltage on the violet wire (relative to ground) when you release the key to the "run" position? (0V or +12V?)

The ball is in your court...
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You're doing well Greg, but based on your measurements, I'd say that the tachometric relay is frazzled.

When the tachometric relay closes properly, this closes the fuel pump relays AND the protection relay C. This is why when you jumped just the fuel pump relays it ran, but ran poorly (and why when you jumped just the protection relay the fuel pumps quit running when you released the key to the "run" position). If you had jumped the fuel pump relays and the protection relay C, it should have run normally.

If you add a jumper wire from the "+" battery terminal to that violet wire in the "x" connector (with everything plugged in), this would simulate a properly closed tachometric relay and the engine should run OK. Alternatively, if you remove the tachometric relay from its socket and add a jumper wire to connect the 30 terminal to the 87 terminal in that socket it should also run OK (this would be my suggestion for your next test).

These jpegs give the information on the tachometric relay.

PS The fuel pumps don't run with just the key "on" -- they only run if the tachometric relay is closed and that only occurs under the two conditions described in the jpeg.

PPS The brief running time is just the time it takes for the supply fuel pressure to fall below the minimum value needed for running (i.e., the fuel pumps run during starter motor cranking which pressurizes things properly; however, when you release the key to "run", the fuel pumps shut off, but the pressure doesn't fall instantly, although it does fall faster if you rev the engine which matches your reported behavior.)
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An uneducated thought--fuel pump or clogged fuel filter?

 

After reading with interest the analysis to date , I agree with 91TR

"...remove the tachometric relay from its socket and add a jumper wire to connect the 30 terminal to the 87 terminal in that socket it should also run OK (this would be my suggestion for your next test)."

Maybe you can open up the relay and rewire/resolder inside and clean up the relay points? If relay points are pitted then relay may be sticking. Also check for corrosion or burnt out contacts at the relay sockets and rear wiring. Clean up all contacts.

I am not sure of what the output signal of this relay should be, i.e. always on or does it send pulses to the fuel relays and pumps? If pulses, then only way to tell then would be with an osciloscope and a jumper wire may not work 100%. If you look inside the relay and there is an IC type 555 (pulse timer) then you are dealing with pulses.

Good luck,
Ron

 

Amazing......carry on......!!!!!!!!

 

Greg -- These are the pin number assignments for the US TR KE injection ECU connectors (your non-US KE won't have as many positions with wires, but the numbers are the same). Measure the resistance (key "off") from pin 2 to pin 21 in the unplugged wire harness end to confirm/deny if the dual water thermister connections are OK.

PS I forgot to add in my PM response that if it runs OK with the tachometric relay socket jumped then the thermisters (and their connections) are OK.
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(Sorry, if this thread seems somewhat disconnected to the rest of you. Earlier Greg had sent me some PMs which indicated that jumping the tachometric relay socket 30-to-87 did restore good engine running, but it seems the problem is with the input signals to the tachometric relay, and not the tachometric relay itself. Since I can't add a jpeg to a PM, I'm posting here.)

Greg -- the foodchain for getting +12V power onto terminal 15 at the tachometric relay with the ignition key "on": is:

battery
to
ignition switch terminal 30
to
ignition switch terminal 15 (with key "on")
to
large AN (blue/black) wire at 2nd from bottom position of connector "w"
to
small A (blue) wire crimped to large AN wire at the metal terminal
to
tachometric relay terminal 15

If the large AN wire at the 2nd from bottom position of the "w" connector isn't going +12V with the key "on" -- something is bad with the ignition switch or the large AN wire connection on that end.

If the large AN wire does go +12V with the key "on", but the small A wire going to the tachometric relay terminal 15 does not go to +12V -- the crimping at the metal terminal is bad and needs to be recrimped/soldered.

If terminal 31 at the tachometric relay is not at ground (i.e., 0.5V or less) with the engine running, just add another wire to the metal terminal holding the two N (black) ground wires and connect it to a nearby convenient ground location.

Let me know what you find post-Wednesday.
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On my Boxer i had a similar thing happen and was told that if you drive the car to empty or even close that the fuel regulators/mabey some other name? will go out and cause no fuel going to the motor.I did replace and the problem was fixed.

 

Greg,

The "A" and "AN" terms are the (Italian) abbreviations for the wire colors (these abbreviations are how the wires are identified on the schematics so it's less confusing IMO to call them by these same names rather than the English equivalents).

The extra black splotches on smaller blue wire is probably OK -- they must have just made a small mistake on the F113B schematics because the smaller wire is just labeled "A" (blue) and not "AN" (blue/black) -- but it's function is very clear from the schematic so don't worry about this minor issue. (And those two bottom positions are electrically connected together on the PWB so it doesn't matter which position has the single wire and which position has the two wires)

The critical point is that all three wires in those bottom 2 positions of the "w" connector should go +12V with the key "on", and that smaller blue wire with the black splotches should go directly to the tachometric relay terminal 15 -- so you must have a problem somewhere in the crimping on the ends or a break in the wire.

Just to be sure, can you confirm that at your tachometric relay:

1. terminal 15 is connected to that same single "AN" (blue with black splotches) wire, and

2. terminal 31 has 2 "N" (black) wires?

I have to agree that it seems really strange that when you supplied +12V directly to terminal 15 (and if terminal 31 remained at ground) that it didn't work, but maybe not being able to fully plug it into the socket was a factor. It also wouldn't hurt to make an AC voltage measurement between terminal 1 and terminal 31 in the socket when you've got the tachometric relay socket jumpered and the engine running -- if you get to the point where you do have +12V on terminal 15 and terminal 31 is at ground, and it still doesn't work, this is the next signal to confirm/deny).

But your next task has to be finding out why the +12V on the smaller wire from the "w" connector going to the tachometric relay terminal 15 isn't going +12V when the metal terminal holding the small and large wire does (and, yes, piercing the insulation would be one way to check things).

Keep chewing -- there isn't any other option

 

Simply put-

the left bank coil will supply a signal to the tachometric relay (and tachometer) to let the system know that it is running, the tachometric relay supplies the signal to both fuel pump relays and keeps the thing running. If the coil does not give that signal, it will briefly run on the cold start injectors and 7-12 coil.

I have found this fault in about 6 cars in my history FWTW.

Brian

 

Wow -- yes, wrong thing to do! (you should've made an AC voltage measurement from terminal 1 to terminal 31 to see what was coming, or not coming, from the LH coil+power module per post #19).

I should have pressed you more when you said the "engine ran OK" when the tachometric relay was jumped, because it might have ran, but it was/is probably running on only one bank.

What you should try now is swapping the LH and RH coil power modules -- if the engine will then continue to run (but only on one bank) then you can be fairly sure that the LH coil power module (that you just moved to the RH side for the test) is toast. If the engine still won't continue to run with coil power modules swapped, then swap the coils themselves -- i.e., it becomes a case of swapping these 4 components around in various combination. If you can get the engine to run continuously (even if only on the LH bank) you know that those 2 of the 4 on the LH side are OK so you should be able to eventually figure out who is/are the bad part(s).

 

i have an 86 TR and i had trouble with the ignition once....after many hours of checking it turned out I had a faulty relay switch located under the right fender. When I replaced it the car started first time and ran ever since...no problems. It is Bosch relay and easy to replace, fwiw

 

So.... the left bank coil is possibly the problem

 

No argument that that was the most likely culprit from the start; however, I was/am trying to convey some information so that other TR owners might be better able to have an intelligent future discussion with F Professionals like yourself when a problem arises.

Please feel free to post anything that you would like -- that's what I do.