Mk1 with ABF - Totally new fuel system and it STILL wont start! Help!

I had a problem aith my old ibiza GTi, turned out to be immobilizer.

But in the process i checked a lot of thing's on it, i had to get a LED test ligt, this can
pick up the small voltage's in the ECU output's.
The injector's are all run with a pos+ from the ECU when ign tuned on, same pos+ as
run's to the coil. The ECU then send's signal earth flash's to the injector's to fire them,
and if i remember correct they all fire at same time, bit like K-Jet as in the in it just pour's fuel in and the valve timing and spark do the work.

A rough way to check is to sit the injector's on top of engine and check if firing, then
check there feed's. Should have con Pos+ when ign on, then earth signal feeds from ECU.

Then check wiring back to the correct ECU pin for firing the injectors.

 

have you had the car put on diagnostics? sounds like the crank sensor to me.

 

I dont think its the crank sensor as I`m getting a spark and the pumps are running when cranking.

I`ve been through all the wiring and now think it could be the relay wiring.

Looking at the golf/vento PDF HERE I`m not sure the relays are wired properly

If not then its either a fubar`d ECU or an immobilised ECU

The ECU should be an imobilised type 037 906 024 AB so can ayone confirm this as I did research and I am told it is a non immobilised one.

 

have you had the car put on diagnostics? if not then do it before you do anything else.

ive just read the other comments and its pretty obvious your injectors arent firing. this is most likely to be a problem with the ecu.

if its non immobilised then it shouldnt cause a problem. if its immobilised then youre going to need the key that relates to it. keys/ecus can be recoded to each other using vagcom. if you have the right key then i'd suggest changing the ecu for a non immobilised one (pre '96).

 

The AB suffix is the non-immobilised ECU I believe. AE or BE is immobilised.

 

Hi John

I finally came to the conclusion that it is a relay wiring issue although mistook the relays and which was which. No problem as I have learned more by messing about with this than I ever thought I would - in fact the black art of auto electrics is unlocking its door to me. I`ll swap them around this weekend.

I have to ask........................with the wires the wrong way around would this stop the injectors firing? I am positive all else works ok so here`s hoping

This wont have fubar`d the ECU will it? [:^(]

Also...............

The round engine loom to engine block loom plug goes in fine and turns ok but it doesnt `lock` in the sense that it clicks home? I have checked continuity and all is fine with no increased resistance. Should it `lock`? It is firm but in theory might be able to vibrate loose. I am not weak so didnt try too hard to force it around.

There was a large (8mm?) spade connector with a red wire and I plugged it into one of a group of terminals (proven all permanent live) on the fuseboard back (top l/h side viewed from the front) or (top r/h side viewed from the rear)

 

Plug doesnt click but the red line on it is on the top 0 degrees and when undone is at 270 degrees (facing the front of the car) when viewed from the nearside

There is a 1.0mm red with a spade connector and that comes from P (6mm terminal permanent live) spade into relay 30 connector

There is no other spare `chunky` wire in the ECU loom and none were wired to fit spade connector N (10mm??)

The only other `chunky` wire from the ECU loom is a red/black that goes into plug D but it has a 0.5mm red spliced into it before it goes into the plug.

The only other chunky red/black is the fuel pump power that goes into plug E14 but there is nothing off it apart from a 0.5mm blue/red wire connected from the spade terminal the pump wires connect to that feeds to relay 53.

The only other really chunky wires are on the original loom and plug into the two bottom large spade terminals in P one comes in on the original loom (I assume from the battery) and the other is beside it and (I assume) goes out to the ignition switch?

All the wires you provided are wired as directed (apart from the ones you told me about)

Which one is the injector feed then?

What are the two reds (1.0 - 1.5mm) that both connect into the Lambda relay 87?

 

Thanks John

I feel confident it should start now. I`ll report back this weekend.

 

Been busy

Think its a faulty wire/connector between relay and engine loom plug Anyway, I`ll try it later today but I`ve been thinking about fault code analysis.

I still have the grey/black?? data link wire. What type of plug do I need to wire it to so I can plug in a code reader and what code reader/plug should I buy?

Is the ABF ECU OBD-1 or OBD-2 (whatever that means) and is it the VAG 16 pin reader plug thingy I need which seems daft when there is only one wire??

 

John

Help please.

I have exhausted every single route and double tested everything and it still points to the fuel pump relay and the lambda sensor relay.

With the fuel pump relay in place in position 2 on the fuse board the fuel pumps get 12volts for 1/2 second and stop. The fuel pump relay clicks when shutting off the fuel pump supply and I assume is being controlled correctly via the ECU although I cant see how as they are not directly connected (are they?)

Therefore the fuel pump relay MUST be ok and working properly if when the ignition is turned on poles 30 and 87 are energised.

When cranking the fuel pumps are energised with full voltage.

When the pumps are receiving 12 volts the feed to the lambda sensor is also getting 12 volts as is the jumper wire and the black wire from the fuse box plug. The only thing left is the feed to the injectors and sensor which should be switched by the relay.

The supply wires to the lambda sensor and injectors are good as is the continuity and resistance so they should receive 12 volts each via the lambda sensor relay once the ignition is turned on and the lambda sensor relay is energised by the fuel pump relay.

The problem is that the injectors and lambda sensor are only getting a minimum voltage of some 0.2 volts when the ignition is turned on with the fuel pump relay in place Even for the 1/2 second they are energised its still only 0.2 volts and when cranked is still 0.2 volts

When the fuel pump relay is removed and is bridged across 30 and 87 the voltage to the injectors and lambda sensor is then a full 12 volts!!!!!!!!!!!!

This is very confusing because the lambda sensor relay is clearly working (as it transfers full voltage from the pump across 30 and 87 with the fuel pump relay bridged) and I have checked it and swapped it with others so I know it is ok and switching the contacts correctly (controlled by the fuel pump supply)

The fuel pump relay has four terminals and the ignition source/contacts 85 and 86 are the only thing removed when the relay is taken out.

The battery voltage from the permanent live 30 is the same whether the fuel pump relay is in place or removed as its only the ignition that switches it so............. why does removing the fuel pump relay and bridging the contacts give full voltage across the lambda relay?

The massive voltage drop suggests some resistance or other but with the relay in or out the pumps get the full 12 volts from pin E14 (as does the lambda sensor relay supply)

So to summarise............

Fuel pump relay in - practically no volts to the injectors even though the relay clicks and has full 12v feed from the pumps

Fuel pump relay out and bridged 30/87 - full 12 volts to the injectors across the relay!!!!!

It cant be the fuel pump relay can it? Its a 167 - is this the right one?

Is it the brown black ECU wire (assumes grounds the supply from 85/86)

Is it the ECU?

Help????????????

 

Relays can fail yes. Especially if operated with low battery voltages. They can burn contacts and cause high resistance.

If you are bridging 87 to 30 this means you are simulating the switch inside the relay. 167 is the correct relay but does the relay enegise? You can check power is being fed to the relay when ignition on and cranking by measuring voltage at 86 with relay removed. The Ecu should supply the ground at 85. If this is all ok its a dodgy relay.

The ECU wire that connects to G1/3 is yellow and blue and goes to 85 on the relay.

Is this an early ABF loom? As later ones don't have the relay. The fuel pump relay supplies the lambda/lambda relay with power via fuse S18 from G1/8.

Do you have a diagram? As its shown on there quite clear.

 

There is certainly no "OBD 1 or 2" nonsense associated with ABF engines and their controls ever! Leave that to the VR6 mob who insist on applying this incorrect jargon to their European engine types.

The data connection from ECU pin 43 will terminate in a 2x2 diagnostic connector for 037 906 24 G/AB or on later 94 onwards 037 906 24 AE/BE/CE/immobilsed with a 16 pin J1962 connector.
The other wires on the diagnostic link will be KL30 battery power and ground. If the vehicle carries the later 16 pin J 1962 connector the positions of the pins are arranged to have the K line on pin 7, power on pin 16 and earth on pin 4.

Please check you ECU part number so that we can rule in or out the immobiliser as part of the problem.

 

The fuel pump relay (type 167) works fine (apparently). With ignition in accessory position it switches the pumps on with full battery voltage to them. The voltage is then supplied to the lambda relay (type 53) also at full battery voltage. This is on for say 1 second and then stops. (This I understand is correct) Turn to crank the engine and the ECU gets a start signal and the pumps run.

The puzzling aspect is that with the fuel pump relay in place and battery voltage at the lambda relay at 30/85/86 I only get 0.2 volts to the injectors and lambda sensor BUT when I remove the fuel pump relay and bridge 30/87 I get a fully switched 12 volts to the injectors/lambda sensor via the lambda sensor relay.

So my question is what has changed by installing the fuel pump relay? Why is the voltage on a fully working lambda sensor relay reduced on 87 with the fuel pump relay in place and fine with the fuel pump bridged?

The ECU has an AB designation so understand it isnt immobilised.

 

It means the relay isn't being switched on. 0.2V basically means zero . You need to check power points for the relay coil. The ecu switches the relay on by earthing via a yellow and blue wire at 85 on the fusbox. This will only happen initially for 2 seconds when ignition on and when cranking. It will then be live continuously when running. 86 should be 12v with ignition on and cranking at all times.

Are your wires all connected to the correct places on the fusebox as shown in the ABF diagram?

Not sure how your loom has been made so it may or may not be as the diagram.

 

Thats interesting..............

The power supply to the Lambda relay is via the fuel pump supply from the MK1 (later type fuse box) from Pin E14 which I believe is the rear loom wiring plug and is livened up via the ignition.

This fuel pump supply feeds to the lambda relay terminals 30 and a jumper then feeds 86 (should it be 85 although I cant see it makes a difference on a 53 relay) so those are the switched and unswitched live feeds and they have full 12 volts with the fuel pump relay in (or bridged) and the lambda relay in place and are correctly controlled by the ECU as it switches off in a second or so unless cranking as you state.

This goes to fuseboard plug D13 which is correct I believe

I`m in the garage now.................

It is 12v with ignition on and cranking.

The lambda relay doesnt click when the ignition is turned on BUT if you put a voltmeter to earth and connect to a terminal the relay works and clicks but doesnt put voltage across to the injectors. If you then try again after waiting a few seconds it doesnt click however if you put the voltmeter across another terminal it clicks and then wont do it again ??????????????? Go back to another terminal and it clicks once and wont again!!!!!!!!!!!!!!! etc etc

Would it be ok to supply the injectors and lambda sensor with another ignition feed positive (say off the cigarette lighter as I dont use it) and bypass the relay altogether?

Thanks in advance for any futher advice - I`m sure its something fundamental but very annoying.

 

Would need a diagram to confirm this. Do you have a pdf version?

Doesn't matter what way round ie 85 or 86. It is shown on the ABF diagram as the earlier way of doing it by using a lambda relay.

Are you saying the lambda relay supplies the injectors?

The injectors need to be on, only when FPR / ECU relay is on. I'm not familiar with your loom so i don't know how its wired. I am going by the original ABF diagram. Personally i would ditch the lambda relay unless they are also feeding injectors etc. Which it probably is.

What you are doing is switching the lambda relay on by conecting it to earth but not properly because multimeters have a very high input resistance so they dont affect what they are measuring. You may be damging relays by doing this though.

If you want to prove they work. You will need to earth both coils of the FPR and the Lambda relay with pieces of wire. If the switch (click)on and supply correct voltages it means there is a problem with the ECU or the connections to it. Meaning its not sinking current to the relays and switching them on.

It seems it is connected to the power correct as 12V is present with ignition and cranking but the is no earth to power the relay coils to switch them on.

 

Yes, the Lambda relay feeds the injectors.

The feed from the fuel pump feed to the lambda shows 12v to 30 when ignition on and cranking (and is cut off after a second or two when ignition is on)

The jumper wire from 30 shows 12v at 85 when ignition on and cranking (and is cut off after a second or two when ignition is on)

The brown black earth to pin 28 on ECU shows 12v when ignition on and cranking and 0.2 volts when ignition off so I believe it is earthing via the ECU (and is cut off after a second or two when ignition is on) so the relay is energising across those terminals properly. The relay clicks most of the time but sometimes not.

The brown black when earthed from the wire in the relay block shows continuity so I assume the ECU earth is working?

Despite all of the above the feed to the lambda sensor and injectors from 87 shows 0.2 volts so there is a massive short somewhere. I cant see how its the ECU as the feed to the injectors crosses the four injector wires and is earthed by the ECU

Also.........I`ve got 3 no 53 relays

When these relays are bench teste doff a battery and powered up across 85 and 86 they click properly in my opinion and when energised there is continuity across 30 and 87 with no apparent resistance and 12 volts

I cant belive that the 3 relays are faulty - or am I going mad.

From what you have said the injectors need to be fed from a relay.

Therefore, if I remove the ECU lambda wire from the relay block and simply earth that terminal I am sure I will have power to the injectors controlled in line with the ECU/FPR

If I then find a suitable ignition feed can I then wire direct to the black/brown ECU wire?