Again: Fuel system electric issues. New relay but fail again.

[KarlosG60 2]

Forgot to upload this draw at the end of "G1 connectivity checks:"

[Bauhaus 3]

Its late and my brain is tired,  but Pin 86 on the fuel pump relay should be going to a switched live wire feed ( Pin 5 in connector G1 could be the switched live feed so double check that one and it should NOT be a ground connection) and Pin 85 is the ECU trigger to activate the relay

[fendervg 33]

Its late and my brain is tired,  but Pin 86 on the fuel pump relay should be going to a switched live wire feed ( Pin 5 in connector G1 could be the switched live feed so double check that one and it should NOT be a ground connection) and Pin 85 is the ECU trigger to activate the relay

That’s pretty much the way I remember it from troubleshooting this before. And to send the signal on pin 85 the ECU needs to see the engine running using the crank sensor and hall sender.

[KarlosG60 2]

11 hours ago, Bauhaus said:

Its late and my brain is tired,  but Pin 86 on the fuel pump relay should be going to a switched live wire feed ( Pin 5 in connector G1 could be the switched live feed so double check that one and it should NOT be a ground connection) and Pin 85 is the ECU trigger to activate the relay

The connectivity between 86 and G1/05 was very poor. But I don't know if I did well.

I will check again today and come here with the result.

 

Edited December 6, 2021 by KarlosG60

[KarlosG60 2]

I'm thinking about if it would be a waste of money to replace this fuel pump relay to new one? To discard things... 🙄

Ref. 357 906 363

 

Edited December 6, 2021 by KarlosG60

[Bauhaus 3]

47 minutes ago, KarlosG60 said:

I'm thinking about if it would be a waste of money to replace this fuel pump relay to new one? To discard things... 🙄

Ref. 357 906 363

 

Replace it... that relay you have is NOT a Corrado G60 fuel pump relay

Edited December 6, 2021 by Bauhaus
Made things clearer

[KarlosG60 2]

13 minutes ago, Bauhaus said:

Replace it... that relay you have is NOT a Corrado G60 fuel pump relay

Afterrun fuel pump relay maybe? 

[Bauhaus 3]

Not sure what that relay is that your using, The best fuel pump relay to use is 191 906 383 C

Pin3 on connecter G1 behind the fuse box is the trigger signal wire from the ECU which goes to pin85 on the fuel pump relay, pin86 on the same relay goes to a switched live (when key is turned)

I’ve seen you been messing about with your fuel pump so unplug it first then check all fuel pump relay connections.

[KarlosG60 2]

On 12/6/2021 at 6:46 PM, Bauhaus said:

Not sure what that relay is that your using, The best fuel pump relay to use is 191 906 383 C

Pin3 on connecter G1 behind the fuse box is the trigger signal wire from the ECU which goes to pin85 on the fuel pump relay, pin86 on the same relay goes to a switched live (when key is turned)

I’ve seen you been messing about with your fuel pump so unplug it first then check all fuel pump relay connections.

Yes, this relay was replaced long time ago by new one from Hella.

 

8/12/2021 - Did few more checkings

• Live wire from Fuel pump relay socket 4 (pin 87) to battery +. Fuel pump should be audible and injector rail too ✅
• Live wire from pin 85 relay to ground, ignition to ON. Relay and fuel pump should be work ✅
• Live wire from pin 3 ECU to ground. Ignition to ON. Relay & FP should be work ✅
• Check voltage to Pin 1 ECU with ignition to ON. Should be give you around 12V. If yes, check voltage to Pin 14 with ignition ON and crancking engine. Should be give you around 12V also. ✅
• Set multimeter on 20V. Put wires on pins 14 & 13 of ECU connector. Ignition key ON. Should give you 12V approximately. ✅
• Ground ECU wires. Set multimeter on continuity. Put wires on pins 13 & 19. Should exist continuity. ✅
• Ground ECU wires. Check continuity between pin 13 and battery negative ( - ). ✅
• Ground ECU wires. Check continuity between pin 19 and battery negative ( - ). ✅
• Pull out relay. LED tester between socket 2 & 3 (86-85 of relay). Live wire from 87 fuel pump relay to battery postivie ( + ). Fuel pump should work. Turn ON engine. LED tester should light up. If not, possible ECU fail. ❌

 

PENDING:

• Check for open circuit in wiring to ECU using wiring diagrams
• Pin 86 must be go to switched live wire feed
• Check if Pin 5 of G1 is NOT ground
• Live wire to Pin 85 from Pin 3 ECU to check if relay works 
• Repeat checking G1 and G2 with fuel pump relay pin sockets
• Search for a R/Y wire to M/02
• Find wires of socket 2 and 3 (85 and 86) at fuse relay box and check

• ECU pin 14 to positive ( + ). Pin 13 to ground ( - ). Pin 3 to LED Tester and to positive ( + ). LED light should be light up. 

--------------------------------------------------

All directions points to ECU failure if I am right.

So, at this point what I can do. Open up my ECU and see something I don't know to look at? Purchase used ECU? Send to repairing mine?

 

P.S: Again, sorry for the 5yo draws.

Edited December 8, 2021 by KarlosG60

[fendervg 33]

It doesn't necessarily mean that your ECU is a total failure, although that is a possibility (they can get damaged by water ingress from the scuttle panel) - it could be a case that the ECU is receiving the proper signal to indicate that the engine is turning and the running - these would be the crankshaft position sensor at the front left of the block, and the hall sender - part of the distributor if fitted, or located to the right of the coil pack on the passenger side of the engine. You could also have some broken wiring somewhere.

Do you have access to diagnostic software such as VCDS? This will allow you to interrogate the ECU to see if there are any fault codes and that all the correct signals are present.

[KarlosG60 2]

6 minutes ago, fendervg said:

It doesn't necessarily mean that your ECU is a total failure, although that is a possibility (they can get damaged by water ingress from the scuttle panel) - it could be a case that the ECU is receiving the proper signal to indicate that the engine is turning and the running - these would be the crankshaft position sensor at the front left of the block, and the hall sender - part of the distributor if fitted, or located to the right of the coil pack on the passenger side of the engine. You could also have some broken wiring somewhere.

Ok, added to my list, but if I can run the engine when I bypass the fuel relay, this sensors doesn't matter if they broken or there are short in these sensors? 

6 minutes ago, fendervg said:

Do you have access to diagnostic software such as VCDS? This will allow you to interrogate the ECU to see if there are any fault codes and that all the correct signals are present.

Yes, I have VCDS for my other car (Golf TSi 2010).

Edited December 8, 2021 by KarlosG60

[Bauhaus 3]

Just to add... on the fuel pump relay,  pin 85 connects to pin3 on connector G1 (the trigger signal) and in turn this goes to pin3 on the ECU. This trigger is a negative signal, so to test you need to put your 12v multi meter or your LED testers  black probe on pin 3 of connector G1 and the your red probe to the switched live, you should also check ECU pin3 and a reading should only be available when your ignition key is turned.

So pin3 at connector G1 or at ECU pin3 should NEVER be at +12

[Keyo 47]

Hi there is an after run fuel sensor its brown by the back of the manifold have you tested this .

[KarlosG60 2]

Thanks, I will check both.

 

Now I am start to looking for a used ECU. I don't know if mine is bad, but...

My ECU number is 037 906 022 DP, will any other reference, like 037 906 022 CP, works or it needs recalibration?

Edited December 9, 2021 by KarlosG60

[Bauhaus 3]

It will work, I’ve never had a problem with this and have used a few ecu’s with different part numbers, the different part numbers relate to the slightly different fuel and ignition maps depending on what fuel is available in the country at the time when the car was originally exported to as well as various internal circuit revisions.

[KarlosG60 2]

Thank you. 

Purchase used ECU it's an option if repair mine it's too expensive. Will check few more things to find my problem and I will decide what to do (burn it all, I supose).

[KarlosG60 2]

Hi,

I just purchased an used ECU + Complete CE2 wiring. Next week will arrive and I will check. It's reference is 037 906 022 CP

BTW, I did few more checkings today. Let's lists them:

 

11/12/2021

• Check Hall Sender Unit, Voltage supply. (Bentley 28.9) ✅
• Check Hall Sender function. (Bentley 28.10) ✅
• Check connectivity from M/02 (R/Y) to R/Y from fuel pump connector ✅

• RPM needle moves when crancking? NO. But the checkings to the Hall sensor was good. I said previously the needle moves, but it don't. I don't think this is a good checking, but... 

• Check if ECU got voltage directly from battery. ECU pin 14 to positive ( + ). Pin 13 to ground ( - ). Pin 3 to LED Tester and LED tester to positive ( + ). LED light should be shrink. If not, ECU is not receiving voltage. ❌

Edited December 11, 2021 by KarlosG60

[KarlosG60 2]

Checking wires in engine bay, I saw the ignition coil maybe missing some wires:

 

 

Ignition coil, spark plugs and spark plug wires are new (well, they got a lot of years -10 maybe-, but less than 1000 kms 😅)

Edited December 11, 2021 by KarlosG60

[Cressa 44]

18 hours ago, KarlosG60 said:

Hi,

I just purchased an used ECU + Complete CE2 wiring. Next week will arrive and I will check. It's reference is 037 906 022 CP

BTW, I did few more checkings today. Let's lists them:

 

11/12/2021

• Check Hall Sender Unit, Voltage supply. (Bentley 28.9) ✅
• Check Hall Sender function. (Bentley 28.10) ✅
• Check connectivity from M/02 (R/Y) to R/Y from fuel pump connector ✅

• RPM needle moves when crancking? NO. But the checkings to the Hall sensor was good. I said previously the needle moves, but it don't. I don't think this is a good checking, but... 

• Check if ECU got voltage directly from battery. ECU pin 14 to positive ( + ). Pin 13 to ground ( - ). Pin 3 to LED Tester and LED tester to positive ( + ). LED light should be shrink. If not, ECU is not receiving voltage. ❌

Do you get 12v if you go from pin 14 + and then straight to the battery negative. If this should be a permanent voltage and isn't,  check your fuses

[Cressa 44]

And when I say check your fuses, pull each one out and use a multimeter set to ohms and check that the resistance across each one is very low

 

[KarlosG60 2]

51 minutes ago, Cressa said:

Do you get 12v if you go from pin 14 + and then straight to the battery negative. If this should be a permanent voltage and isn't,  check your fuses

I will check that, thanks.

46 minutes ago, Cressa said:

And when I say check your fuses, pull each one out and use a multimeter set to ohms and check that the resistance across each one is very low

 

The engine starts fine without any trouble when I bypass the fuel pump. I don't think there will be any bad fuse, but I will check that too, who knows.

Thanks

[KarlosG60 2]

At least!!

It was the ECU. I just plug the 'new' ECU and fuel pump and relay works and sounds loud and clear. And the engine starts fine. Well a LOT of white smoke and smells like hell and burned oil, but it runs!!! After spending 350e... But it runs!

Next step: clean the alarm system, throw out the car and check and repair wires

 

Thank you so much for your help guys! 😉

 

[fendervg 33]

Ah, that's great to hear and glad it worked out for you after all that painstaking troubleshooting and diagnostics.

I think ECU failure is rare, but does happen, especially due to water damage.

[KarlosG60 2]

It begans with the new fuel pump. I think it burns gauge cluster and fuel pump relay for some short, because the fuel pump hoses lose fuel. Then, one day after replace relay, the fuel accumulated at the top of the fuel pump touches the connector, and then burns the ECU.

It's all of kind of related issues, that ends with a burned ECU. I will open, to see if is repairable. 

But now, the light (of the street) at the end of the garage is closest now. 

[Dox 23]

A short in the pump would blow the fuse, the ecu switches the low current side of the relay, so a pump short can't affect the ecu.

 

Its more likely the capacitors in the ecu are old and blown?

The ecu can also be damaged by not have a good engine to battery earth connection, starter current tries to earth via ecu sensor connections - usually its the injectors that remain fully open when this hs happened.