Been having on going issues with setting up the fuelling/emissions on my mk2 8V GTi running Digifant. Went out today fired the old girl up, drove hundred yards up the road got a big puff of black smoke from the exhaust and the engine died. Car won't even start now. Tried turning the dizzy and changing all the leads round and am still getting nothing. Engine just turns over with no attempt to splutter into life. Does anyone know what could be my problem? TIA Nick
Have you checked anything, or did you just run straight for the computer? First step: Take a spark plug out, put it back in the end of the lead, sit it on the inlet manifold, and turn the engine over, and see if you're getting a spark. If the car doesn't even cough, chances are you've got no spark, or no fuel at all. Does it reek of fuel after you've tried to start it for a bit? Check the wires to the coil, and the plug on the distributor are well connected. Take the dizzy cap off and check the rotor arm / cap contacts look ok.
Sorry Mike should have actually written what i have checked so far. Before i posted i had done the following: Taken spark plug out and put it back in the lead and rested it on the inlet as you said and turned it over, its getting spark although it seems very weak. Its getting fuel as the spark plugs were all wet after trying to turn it over for ages. The contacts in the dizzy are ok where they would make contact with the rotor however the sides of the contacts have a little bit of powdery corrosion. When the engine died the fuel pump kept running and i got a constant clicking/ticking noise coming from the fusebox area. Thanks for the reply Mike_H
If you've got a spare rotor arm or dizzy, try swapping them in. My 16v wouldn't start recently... the spark looked a bit weak. I changed the rotor arm and cap, and it fired first time. If you switch the ignition on to position 2, does the pump run and stop, or does it run constantly? I'm slightly concerned that your ECU might have blown, but I don't think you'd get a spark at all, in that case. Keep an eye on the oil level, in case your sump is filling up with fuel.
Hi Mike Thanks for your replies, i swapped in a spare dizzy i had in the garage which made no difference, I cleaned the contacts in the cap as they were dirty. When ignition is turned on the fuel pump only primes so i guess the ecu is OK. Looked over the engine yesterday afternoon in the daylight and the first thing i noticed was one of the wires to the blue temp sensor had snapped off. Have replaced the plug and wires and touch wood it now runs again.
I spoke too soon. Its dead again now. Exactly the same thing happened. Started car up, running OK for a couple of mins then went to pull away, misfired really badly then big cloud of black smoke and has now gone back to not starting.
have you checked all the engine earths? as i had a similar prob on my 8v but I blew my ecu which was why it constantly pumped fuel but hopefully yours is ok!
I think my ECU is OK as the fuel pump only primes when ign is switched on. Unless there are other syptoms of a naffed ECU. Will check all the earths though tomorrow.
Check the engine earths anyway (one on the gearbox, one on the head). It's an easy thing to rule out.
Mike, on the digifant ECU loom there is a long earth cable, does this go to the battery or somewhere else in the engine bay?
I've never had to dabble with an ECU earth. How long is it, and what sort of connection is on the end? Is it loose now?
It has a ring terminal on it. Its long enough to reach the battery, however i used to have it earthed to the inlet manifold. When i moved it and earthed it to the battery this was when i started getting the problems.
I'd just find a good earthing point in the scuttle somewhere. Sounds like it's meant to be screwed to the body. Worth a try.
the earth cable you mention is for the TCI-H unit, not the ECU specifically, it is supposed to be earthed to the battery there are other earths on the side of the head, these are for the ecu. gearbox earth is usual suspect for blown ecu or trouble starting the car, had similar prob on my digi but luckily i didnt blow the ecu. Pull the plug from the main fuel pump under the car and turn key 1 click, should hear the in-tank pump prime. fact relays went mental suggests you have a wiring fault, when you turn the key click does the ecu relay click?
When i turn the ignition on a relay does click and then the fuel pump primes and stops. But that is when i turn it two clicks on the ign not tried only turning it once. The cable has a ring terminal and there is two earth wires not just one. Gearbox earth should be OK because i only recently cleaned it up. Cheers Nick
Just been reading through some other similar probs people have been having and come across a post about the ECU Relay should be a number 32? Mine has a number 53 Relay which is the same as the horn. Apparently the 32 Relay has different pin outs and is not the same. Could this be the problem although the car was running up until the end of last week? Cheers Nick
if yours is a pre-90 then it should be a 53 relay, post 90s use the 32 relay ignore any posts by me that said otherwise I was wrong
Oh OK RJ . Don't no what the hell is up with mine now then. I've tried two different blue temp sensors and they made no difference unless they are both dead!
