Hi All Purchased a non running 1989 8v gti with a solid shell around February time with the intention of getting it back on the road for the summer. Engine had done 196,000 and someone had put gravel under the rocker cover. So got hold of a replacement engine that had done around 115,000 and switched them over. Went to start it and no fuel pump priming noise. So I've replaced the in tank fuel pump, the relay, fuel pump under the car and the fuel filter. I have fuel to the injector rail and I have a spark at the plugs. I've checked the timing is correct. The engine turns over on the key but it wont fire into life. It also wont go with easy start sprayed into the inlet manifold. I've not checked compression yet but will do next weekend. As a side note the battery light on the dash is illuminated with ignition on but no other lights on the dash do anything. I recall some other red lights should be flashing with the ignition on and turn off once the engine is started. I'm not sure if this is related or would have anything to do with it not starting but I guess it suggests something else is not quite right. Any suggestions would be much appreciated. Andy
if its a CE1 fusebox the earth for the cluster goes to the side of the head, perhaps that was missed during the swap. its a brown/white wire, there should be another wire from the ecu to the head in the same spot also. does the isv buzz with the ignition on, and does fuel pump prime on ignition and run while cranking?
You should have an oil light on too which will eventually go out when oil pressure is reached. Do the light/s remain on while the ignition is in crank mode or do they go out? A sign that it might be a worn out ignition switch.
Ok quick update. It is a CE1 fusebox. I have the brown and white wire earthed to the head along with one that appears to go to the ignition coil bracket and one that must go to the ecu. Pump primes at ignition on but hard to tell when cranking. The isv is not obviously buzzing. Should it be permanently buzzing once ignition is in? It did have a broken connector so replaced with spade connectors to each terminal. Tested with volt meter and I'm getting approx 8v. I don't know if that's correct? Had another look at the dash warning lights. Battery light stays on, oil light flashes once very quickly and the engine temp light flashes a few times and goes off. Indicator lights are working as is the headlight light. I've not tested compression yet but I'm really hoping I've missed something obvious.
it should be buzzing constantly with the ignition on, sometimes they are pretty silent in operation but you should feel it vibrate. The ECU pulses the valve earth so thats probably why you only see 8v at the plug I guess. does the oil light only go off while its cranking, or immediately with ignition? it should only go off once you get some oil pressure, so if it goes off right away with ignition it suggests an issue with cluster or oil switch wiring... the light with ignition is handled y the switch in the side of the head which should have a blue/black wire. switch itself should be 0.24 or 0.3bar rating and is blue or brown in colour if genuine. Coolant light is working as intended though. Not that this would affect the engine running... another thing to check is if you unplug the main pump under the car and switch the ignition on you should hear the in-tank pump prime
I definitely cant feel the isv vibrating. I switched it out for one off the old engine and it made no difference. Could the isv not working prevent the car starting? The oil light flicks on for a split second and then stays off. I have a spare switch I could try off the old engine. Is this something that would prevent it starting? I've already replaced the in-tank pump as it wasn't priming originally and now you can hear it clearly. The main pump under the car was also replaced as was the fuel filter at the same time. The only thing I can't tell is if the pump is working whilst cranking but I have fuel at the injector bleed screw.
If the ISV isnt buzzing this suggests ecu is not powered up properly, check the spade plugs in the scuttle for corrosion. You should see ignition live on the black/yellow wires, the green/red should be live when cranking and the red/yellow is the earth trigger for the fuel relay. the fuel relay is slot 2 and should be a 67, 8-0 or 167, the ecu relay is in slot 1 and should be a 53. Check fuse 17 this one triggers the ecu, though fact it does anything at all suggests ecu is at least triggering...
I have a brand new 167 relay in slot 2 and I have a 53 relay in slot 1. I won't be able to test the connections until later. If it turns out I don't have power at the spade connectors to the ECU is there another relay I can plug into slot 1 or can I put a jump wire in? I assume the ECU also controls the injectors at start up? If so I could make sure they are actually working also. I only know I have fuel at the injector rail bleed screw. The spark plugs smell faintly of petrol but certainly not obviously and don't have fuel on when I've pulled one out after a few cranks. I would assume they would probably faintly smell of fuel either way as they would have had fuel in the cylinder at some point in the not too distant past.
Latest update. Tested the injectors and they were spraying fuel. So at this point I was almost certain it was compression. Did a compression test and had no compression on cylinder one and almost none on the other three. Was thinking it was time to take the head off but thought I'd give it a quick tow down the road to get the compression up and see if it'll jump start. Low and behold it fired into life! albeit very rough. Kept it running for a while to get some temperature into it and then did another compression test. Good compression now on all cylinders. Still wouldn't start on the key and had a strong smell of fuel so it seemed like something was telling the ECU it needed more fuel. So got some jump leads on my other car so I knew I had good power to the starter motor and unplugged the blue and black coolant sensors. After around 20 seconds turning over it fired into life. Adjusted the timing on the distributor until it was running nicely. Plugged the black sensor back in and all fine. Plugged the blue one in and the car cut out instantly. I got a spare blue sensor and plugged that it. It didn't make the engine cut out but made it run very rough again. As it stands now I have the black sensor plugged in and the blue not plugged it. The engine doesn't start perfectly but it starts after around 5 seconds of cranking and then runs nicely. But it is still a bit of a struggle to start. So I'm thinking will a new blue sensor stop it struggling to start? Other than that I have the oil light constantly flashing and also the coolant temp light constantly flashing. But the coolant gauge is working fine.
have a good look through my digifant troubleshooting guide next, theres a section on blue temp sensor testing https://clubgti.com/forums/index.ph...ose-and-tune-your-mk2-digifant-gti-8v.124949/ the black sensor is just for the dash clocks so wont affect anything
Thanks rubjonny will take a look. Very relieved to have it actually running. I was starting to feel sure I had been sold a dud. How about the oil pressure light constantly flashing? I suppose it's either a bad sensor or I actually have low oil pressure. I seem to remember there being a buzzer if you lose oil pressure?
for the light at idle/ignition, this one is handled by the switch on the side of the head with the black/blue wire. to check if its wiring issue disconnect the wire and the light should never come on, earth it and light should flash. if that happens check switch in the side of the head, it should be 0.24 blue or 0.3bar brown the white one in the filter housing does light and buzzer at about 2k rpm, earth it to disable and if you disconnect it then light and buzzer should flash
I've fitted a new blue sensor and I can now plug that in without the engine running rough or cutting out. The only issues I'm having now is a slight judder every few seconds and the first few turns of the engine on the key the engine turns very slowly before it starts. I've not had a chance to look into the oil light so it's still flashing at the moment.
ok getting there! with the starting issue make sure the gearbox earth is good, the later MK2 moved this to a stud on the end of one of the upper bolts holding the gearbox on, so make sure thats what you have. If not, raid the local scrappy for 1.8-2.0 mk3 golf and take the battery, alternator and starter cables. nicer clamp design and a little bit beefier. Take the bolt from the gearbox too if you dont have one with a stud on it. oil light look around for a snapped blue/black wire round the side of the head, make sure its not earthed anywhere. if its connected to the switch in the head remove it and see if the light goes out. if it does, take the switch out and check its a 0.24 or 0.3bar rating rough running might clear after a good long run, if nothing else it'll tell you if the car is otherwise behaving ok. get the box earth sorted first though if it goes bad you risk blowing the ecu
Do you have an image of where that earth should be? I earthed to one of the big bolts attaching the gearbox to the engine. I've noticed a few more things now too! Side indicators are not working, horn is not working and wipers are not working. Are these likely to be a related issue?
Sounds like you have the late earth setup so its all good, but can see at the top left of this here piccy: If the main indicators work then all the wiring to the engine bay is good, check the side repeaters are plugged in, there are 2 connectors near the header tank between the main lighting loom and the wiring up into the scuttle. does the heater blower motor work? if not, wiggle relay 17/18 in the fusebox. also check the headlights, if they work fine then the ignition switch is ok at least.
Great thanks I'll change to that earth later if I have it. The original gearbox had a switch with two terminals for the reverse lights and the new one has a big switch with multiple terminals. As we're on the subject I'm also struggling with the reverse lights. I followed this guide http://www.brokevw.com/reverseswitch.html But the reverse lights just stay on permanently if I put the connectors on pins 2 and 8. Main indicators work no problem, heater blower works fine and headlights are working. I do have a a block connector and a couple of spade connectors over near the header tank that are not plugged into anything because they have nothing to plug in to...
Side indicators are working. Bulbs just needed to be reseated. The steering column has been butchered at some point in the past. It's cracked and I can see inside. The wiper stalk doesn't have the button for the MFA. The wipers don't work but the washer jets are working. The metal ring for the horn on the back of the steering wheel appears to be missing. So the metal contact has nothing to contact with. I have two spade connectors under the horn cover which if I touch together make the horns sound. I guess at least I know the horns work. I swapped the oil pressure switch with a spare and that's now working. So I'm now down to just the horn, reverse lights and wipers not working!
if the washers work but still no wipers try a different relay, get a mk3 99 relay at least it wont be a waste of money if its not the relay as you'll get variable intermittent wipers if stalks been messed with that would also be on the list with reverse lights you dont actually need them to pass, if wiring it as per brokes thread doesn't work I would say switch is bad. he covers how to split and check them so thats worth a try, but you can get them on ebay
