T3 2.1 (ss engine) Digifant, misfire after 15mins
Posted: 04 Jun 2017, 12:52
I first experienced this after getting my bus out of 6 months storage. On start-up it runs well for a while, then after about 15mins (10km) it starts to ‘misfire’. The new plugs and the inside of the exhaust tail pipe are sooty. As reverse into parking space, I notice black smoke.
So far, I have changed the following:-
1) Spark Plugs (NGK-B6ES)
2) Beru Dist Cap
3) Beru Dist rotor
4) HT Leads BERU (ZEF 520), existing HT lead resistance on cyl-3 was 6760 ohms, cyl-2 (ohmmeter reading would not stabilise), so I replaced the lot. The plug leads should be 6,000ohms an the coil lead 2,000ohms.
5) Replace original Green Label ignition coil with an OEM 'Green Label', Bosch 0 221 122 349 / VW- 211 905 115 D
6) Fuel filter, because I had one and the original had done 102,921 kms, I have since read somewhere that these should last the life of the vehicle.
7) Replaced the inner and out injector seals.
I have also checked:-
Digifant ECU, for signs of corrosion on terminals, I found none
9) 'Sensor one' checked ok, replaced with new anyway.
10) All engine bay electric terminals cleaned.
11) Injector spray pattern, 'fan' shape as expected, seals not yet replaced, (currently on-order). However, cyl 3&4, have two inner seals per injector, without doubling up the injectors with single seals would not reach the inlet manifold? Might this make it set up susceptible to leakage? It’s been fine for the first 100,000 kms?
12) I have established that cyl-3 is running a little cooler, (IR temp sensor), swapping injectors 3 & 2 gave no improvement.
13) Compression test:- cyl-1 = 12.5bar; cyll-2 = 12.0bar; cyl-4 = 11.7bar; cyl-3 11.2bar.
12) I thoroughly cleaned the oily residue from the air way of the Air Flow Meter then VERY CAREFULLY removed the black cover to see if there was anything obvious. The resistor array sub-straight has been ‘printed’ with a ‘teflon like’ coating, this showed clear signs on wear, at the RH end. The coating has worn through to the sub-straight to a length of about 3mm on both tracks, caused by the contacts. I carefully cleaned the coating to remove the black deposit, leaving the remaining coat unaffected.
The fault continues. Any advice and or guidance would be fantastic.
Gary
So far, I have changed the following:-
1) Spark Plugs (NGK-B6ES)
2) Beru Dist Cap
3) Beru Dist rotor
4) HT Leads BERU (ZEF 520), existing HT lead resistance on cyl-3 was 6760 ohms, cyl-2 (ohmmeter reading would not stabilise), so I replaced the lot. The plug leads should be 6,000ohms an the coil lead 2,000ohms.
5) Replace original Green Label ignition coil with an OEM 'Green Label', Bosch 0 221 122 349 / VW- 211 905 115 D
6) Fuel filter, because I had one and the original had done 102,921 kms, I have since read somewhere that these should last the life of the vehicle.
7) Replaced the inner and out injector seals.
I have also checked:-
Digifant ECU, for signs of corrosion on terminals, I found none9) 'Sensor one' checked ok, replaced with new anyway.
10) All engine bay electric terminals cleaned.
11) Injector spray pattern, 'fan' shape as expected, seals not yet replaced, (currently on-order). However, cyl 3&4, have two inner seals per injector, without doubling up the injectors with single seals would not reach the inlet manifold? Might this make it set up susceptible to leakage? It’s been fine for the first 100,000 kms?
12) I have established that cyl-3 is running a little cooler, (IR temp sensor), swapping injectors 3 & 2 gave no improvement.
13) Compression test:- cyl-1 = 12.5bar; cyll-2 = 12.0bar; cyl-4 = 11.7bar; cyl-3 11.2bar.
12) I thoroughly cleaned the oily residue from the air way of the Air Flow Meter then VERY CAREFULLY removed the black cover to see if there was anything obvious. The resistor array sub-straight has been ‘printed’ with a ‘teflon like’ coating, this showed clear signs on wear, at the RH end. The coating has worn through to the sub-straight to a length of about 3mm on both tracks, caused by the contacts. I carefully cleaned the coating to remove the black deposit, leaving the remaining coat unaffected.
The fault continues. Any advice and or guidance would be fantastic.
Gary
