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

[KarlosG60 2]

How are you guys.

I came again to the forum because I just had few moments ago the same problem that make my Corrado stay at parking for months.

We came from here:

https://the-corrado.net/topic/86777-fuel-pump-relay-buy-vw-original-or-hella/?tab=comments#comment-1030442

 

So, today I tried to go out with my G60, because I need to test how it works outside. But at the very first climb in my town, the engine stops suddenly and never starts again. Every try came with the electrical noise, caused/origin by the fuel pump relay, which was replaced not too long ago. I tried to pull out other relays and try to run, but did not work. I tried without the fuel pump relay: no noise, but either run (obviously).

At this point I really don't know how to continue. I really need help to solve that issue, or maybe I need to really start thinking about selling my Corrado, because is so depressing this situation. I'm not an electrical expert, so is very confusing for me.

 

If this helps, the steps I made to arrive here are:

1) Fuel pump fails. It was replaced by another that is, theorically, 100% valid for that car: If I'm not wrong, was this pump: https://www.ebay.es/itm/143893332324?hash=item2180b60164:g:NdEAAOSwPCBgZIPt

2) After replacement and fuel fillment, the electrical noise came in to the game, and after few tries, all the gauges was gone.

3) All gauges are replaced. The electrical noise continues. 

4) Fuel pump relay replaced by new one from Hella. The electrical noise keeps, but with a fuel tank fillment, the noise disappears.

5) Today, the problem repeats. The fuel tank are at 1/2 capacity or more.

 

If anyone can and like to help me, I can give it my phone number to establish a permanent contact. 

 

Thanks and regards.
 

Edited May 28, 2021 by KarlosG60

[KarlosG60 2]

I forgot:

The fuel pump, flange and fuel leveler, all of them was replaced. Only the fuel pump is not OEM.

 

The fuel pump relay from Hella is this: 4RP 008 189-15

Edited May 28, 2021 by KarlosG60

[1xshaunx1 27]

I don’t have a g60 but the fact your gauge went would suggest something to do with the replacement of the fuel sender or wiring at the tank end. Surely not coincidence can you try disconnecting the fuel gauge wire and see if that makes a difference, is there an earth to the tank top I would check into that too. Try testing how many amps that pump is dragging it maybe it’s faulty and dragging too much power through that circuit. 

[KarlosG60 2]

Thank you @1xshaunx1.

I managed to solve the issue with the help of a friend. So the problems with the fuel pump and fuel pipes are not over, yet.

So pulling out the relay and making a wire to connect 87 with 30 directly, the fuel pump received power and I drove the car to the garage where I will check, step by step, what is the mess here.

Never Ending Story, the Corrados, I guess...

 

[1xshaunx1 27]

6 hours ago, KarlosG60 said:

Thank you @1xshaunx1.

I managed to solve the issue with the help of a friend. So the problems with the fuel pump and fuel pipes are not over, yet.

So pulling out the relay and making a wire to connect 87 with 30 directly, the fuel pump received power and I drove the car to the garage where I will check, step by step, what is the mess here.

Never Ending Story, the Corrados, I guess...

 

No worries my friend. Keep at it you will get there. It may be a short on one of the powers to the fuel tank

[fendervg 33]

The fuel pump relay also gets an ignition on signal from the ECU relay - if this is not there, then it won't bridge power to the pump - if you look at the diagram on the side of the relay, it will show you which pin is which, and you could check with a multimeter or test probe connected to a known good earth to see if this voltage is there - just checking, I think this is pint 85, the small one. I don't have the wiring diagrams to hand, but I think it's relay 167 that the signal comes from.

Hope this helps - I've had a nightmare troubleshooting this stuff previously, but bridging is good to have the pump running permanently, lets you move the car and proves the pump is working etc., but you need to figure out if the relays are working and if the signals that switch them are there. Best of luck and hope it gets sorted.

[KarlosG60 2]

Hi, I'm still working on fix that.

I've done a couple of electrical checks, following Bentley manual. I followed the Fuel Pump Checking and Fuel Pump Relay, Checking instructions.

 

Fuel Pump Checking

 

The fuel pump works when you directly give power with wires from fuel pump relay socket #4 to + and I can able to run the engine without any troubles with that wire connected. Bentley says to replace the relay. But is new. I don't think it is the issue (I checked the relay out of the car and the coil was acting properly).

But with the ignition key, despite I can hear the fuel pump at first turn to ON position, it cannot turn engine ON. 

 

Questions related to that test

· What it means manual when it says "If NO or only one pump runs". Where is the other pump? It can be the reason? I can listen the fuel pump and run the engine. So I don't know.

 

 Fuel Pump Relay, Checking 

 

·Tester from 6 to ground it's OK

·Tester from 2 to ground it's OK

·Tester from 6 to 4 it's OK

 

Also, I've done the other tests:

 

But the LED never lights up. 

 

@fendervg

What relay is that from ECU? How can I check?

 

 

 

 

Apart from this, my Corrado has an alarm installation (Gemini 2255) made, but supposedly bypassed because there is a brown wire not connected to ground, which if it is connected, it works (doors close, red led lights up and off...). I assume that it is not preventing the pump from working because that brown wire is bypassed, but it is something I have to check and it is going to take many many hours.

 

So, I would like to do some more check beforehand that you can think of. Thanks.

 

 

 

 

 

 

[KarlosG60 2]

Another question.

The fuel pump and relay pump should be audible every time I turn the key to ignition position? 

[Cressa 44]

If the car runs when the relay is bridged,  you defined to look at what switches the relay. And if you say there is a dodgy alarm/ immobiliser wiring then this is where I would be looking, and remove it.

Make it all stock original and then you know what you are working with.

Good luck 🤞

[fendervg 33]

As far as I can remember there is an ignition live to the fuel pump relay, but it is switched by a wire from the ECU relay that tells it the engine is turning and needs fuel. If you get hold of a wiring diagram and look at the small circuit pictures on the sides of the relays it should become clearer.

In my experience the VR doesn’t prime and keep the pump running in the same way as the Mk2/16v engines, and it shouldn’t really be audible as the pump is well insulated in the fuel tank.

As above, check wiring, replace both relays and check to see if the trigger signal is coming in. Alarm and immobilisers are designed to splice into the fuel and ECU circuits to cut power to them, so are a likely suspect.

[KarlosG60 2]

8 minutes ago, Cressa said:

If the car runs when the relay is bridged,  you defined to look at what switches the relay. And if you say there is a dodgy alarm/ immobiliser wiring then this is where I would be looking, and remove it.

Make it all stock original and then you know what you are working with.

Good luck 🤞

IDK if the alarm got immobiliser, because at yet, I can't find any wiring diagram of it, only some other Gemini alarms.

I will check anyway. 

Ah, I forgot, there are some pics of that shit installation. 

 

 

[Dox 23]

Quote

 

Someone needs to remove the Bentley images as Toby can get aggro over them

[KarlosG60 2]

Sorry, can't edit.  I didn't think I shouldn't upload it. 

[fendervg 33]

I’ll try and remove them. It’s still for sale and copyright unfortunately.

[fendervg 33]

Done now - deleted attachments.

For the record, the VR only has the one in tank fuel pump - the 16v and G60 had an in tank lift pump and the main pump mounted underneath the body where the fuel filter is.

The ECU relay is #109 and the fuel pump relay #167/67 - look at the side, they will have a diagram showing the wire and terminal connections and how the relay is switched.

[Cressa 44]

As for the alarm, trace each wire and remove it. Join back any that have been interrupted by the Gemini system. Then see what you are working with

[Keyo 47]

19 hours ago, fendervg said:

Done now - deleted attachments.

For the record, the VR only has the one in tank fuel pump - the 16v and G60 had an in tank lift pump and the main pump mounted underneath the body where the fuel filter is.

The ECU relay is #109 and the fuel pump relay #167/67 - look at the side, they will have a diagram showing the wire and terminal connections and how the relay is switched.

Late body g60 also only has one pump - and uses the early in tank vr 3 bar pierburg pump- same bracket as a vr for fuel filter.  Fuel pressure regulator they are obsolete on a g60 though what a shit show. My guess is your electric plug/cabling on fuel pump or sender unit is wrong- the pump you have fitted is the single pump same as a VR or late G60 my car is the same.  

Edited October 29, 2021 by Keyo

[KarlosG60 2]

Hi guys, I continue working on that issue.

I focused finding the main issue but also disarming and removing the shit alarma installation.

And I hace a question about this red/yellow wire, that was shorted to fit the alarm...

It is the red/yellow with a grey cable in it. 

What is and where it goes? Fuel bomb 30B yellow connector? It is shorted too, and the grey came from here. But I dont know if will be safe to repair the two sides and merge each other.

Edited November 27, 2021 by KarlosG60

[Cressa 44]

I thought red yellow was a switched live off the top of my head. I wouldn't merge the 2 sides together unless they were of the same size and colourings, that would be asking for trouble.  Have you found the main alarm and work back from that

Do you have a Bentley manual with the wiring diagrams In?

[KarlosG60 2]

49 minutes ago, Cressa said:

I thought red yellow was a switched live off the top of my head. I wouldn't merge the 2 sides together unless they were of the same size and colourings, that would be asking for trouble.  Have you found the main alarm and work back from that

Do you have a Bentley manual with the wiring diagrams In?

Seems the same size. The colours on both sides are the same red yellow.

 

Yes I got bentley

[Cressa 44]

1 hour ago, KarlosG60 said:

Seems the same size. The colours on both sides are the same red yellow.

 

Yes I got bentley

Join them then. First just do it using screw connector blocks to see if all is okay before doing a proper solder and heat shrink permanant fix 👍

[KarlosG60 2]

21 hours ago, Cressa said:

Join them then. First just do it using screw connector blocks to see if all is okay before doing a proper solder and heat shrink permanant fix 👍

Joined. Check that exists connectivity on both sides. The issue is not solved yet. Fuel bomb not working.

I made a lot of checks (but i am completely .ignorant with car electrics) and I cant find the problem.

I removed many alarm wires. At this point I think the Gemini alarm is not interfering with the car, so the problem should be another thing.

Edited November 28, 2021 by KarlosG60

[Dox 23]

"Fuel bomb"? Fuel pump?

The pump will run;

1, When ignition first turned on

2, When cranking engine over

3, When the engine is running

All the above assume the ECU is powered up? Tacho reads RPMs on the dash when cranking?

 

[KarlosG60 2]

@Dox

Yes, tacho works when cranking.

 

 

Ok, little update.

The pin 85 of the relay is not receiving signal. 

So, what I needto check? Maybe is ECU dead?

 

[KarlosG60 2]

Forget my last message. I am going to try to put my problems in order, to be very clear about what I am looking at and what I find.

I uploaded some very poor draws made in Windows Paint. I'm under Linux right now and I don't know which program to use that is as easy as paint, so I use old Paint version which is online. So, you are free to make some laughs

 

5/12/2021

• Checked continuity between ECU pin 3 and relay 85 (if I remember well, it's socket number 2 on relay fuse box). Continuity It's OK:

So, ECU wire is OK, right? No shorts.

 

Next, I repeated the Bentleys checking called Fuel Pump Relay, Checking (page 20.12) that I made days ago:

FUEL PUMP RELAY, CHECKING

• Fuse 18 OK? Yes (It has also been replaced by a new one)
• LED tester between terminal 6 and ground ( - ). Light up? YES
• LED tester between terminal 2 and ground ( - ). Light up? YES
• LED tester between terminal 6 and terminal 4. Light up? YES

So I continue to next step.

• Turn ignition OFF. 
• LED tester between terminal 2 and terminal 3.
• Switch ignition ON. LED light up for 1 second? NO, LED is not lighting up.

Bentley's at this point say "Check for open circuit in wiring to control unit using wiring diagram". I only made a checking with my eyes, searching for some wire short. I don't see any short. Where I need to start to looking at? Which wiring diagrams I need to look at?

Remember that I have a Gemini alarm involved but it shouldn't be bothering anymore, since the red-yellow wire from the Z1 connector and which is supposedly the injection one (if I'm not wrong), has been repaired (talked about in previous comments in this thread). 

 

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

After following the Bentley's I decided to search for connectivity between the relay fuel pump and wires from connector G1.

Using this page: http://www.a2resource.com/electrical/CE2.html

I use my multimeter to search for connectivity. But if you look at that page, the G1 colors are (last column):

G1	Engine Compartment/Management, Right Side		White
G1/01	-	F/2	-
G1/02	Outside Air Temp Sender Ground	Gauge Cluster (MFA)	Brown/White
G1/03	ECU- Fuel Pump Relay Turn-On (gas), Engine Temp Sender (Pre-heat, diesel), thermoswitch for preheat (carb)	Fuel Pump Relay Power	Red/Yellow (gas), Blue/White (diesel)
G1/04	Ignition Coil Pin 15 (Digifant and CIS-E), Motronic ECU Pin 14 and coil power stage Pin 1(Motronic), Altitude Correction and Fuel Cut-Off Valves (diesel)	Main Fusebox Start/Run Power	Black (gas), Red/Black and Black/Red (diesel), Violet/White (carb)
G1/05	Ground on Cylinder Head	Ground (for gauges/warning lights)	Brown/White
G1/06	Motronic ECU Pin 34, Vehicle Speed Sensor	Main Fusebox Ground	Brown/Red
G1/07	Overrun Cutoff Valve, G60 Difigant ECU Power	Overrun Cutoff Relay, ECU Relay	Brown/White (Carb only) or Black/White (G60 only)
G1/08	Heated Oxygen Sensor Power	Fuel Pump Relay Output, Fuse 18	Red/White
G1/09	MIL Lamp from ECU (TDI)	Gauge Cluster MIL Light	Yellow/White
G1/10	Digifant/Digijet ECU Power, Injector Power (1989 only), ISV Power (G60 only)	Digifant ECU Relay Output	Black/Yellow
G1/11	Vehicle Speed Sensor	Gauge Cluster	White/Blue
G1/12	Ignition Coil Pin 1 (all Mk2, most others '90 only), ECU tach signal (all 91+ except Mk2)	Tachometer	Red/Black (coil) or Green/Black (ECU)

And this is my G1 connector:

- Pin 1, empty

- Pin 3, blue-yellow

- Pin 5, brown (talk about later). Not coincidence (is full brown) but works as ground too.

- Pin 7, empty

- Pin 9, empty

- Pin 11, white-blue. This is the same colors.

 

- Pin 2, grey-brown.

- Pin 4, two black wires?

- Pin 6, brown

- Pin 8, red-yellow

- Pin 10, black-yellow

- Pin 12, green-yellow

You can see that my G1 colors is not full coincidence with the G1 colors table of that page, but I think this don't mean that my failure is here because I used the car everyday years ago and nothing about the alarm or the fuel pump was a trouble.

G1 connectivity checks:

• G1/05 with relay 86 (socket #2 I think). Very poor connectivity. My multimeter only makes single and low "bip" at the time I prick with the tip. I have a video if you think you need to watch and listen.
• G1/05 with relay socket #1. Connectivity OK.

 

 

And that's all the work for today. I don't know how to continue or what to check, so I stopped before I burn in flames my Corrado with the last fuel litres it has.

 

 

Thank you guys

Edited December 5, 2021 by KarlosG60