Hi all, I wonder if anyone can help. I have just fitted a standard abf into my mk2 golf. I am running twin dcoe 45’s, and using the original ecu and ignition set up. I have simplified the wiring down to the knock sesnsors, distributer, crank sensor and coil. The engine starts and runs, however I have a few issues. One of which is that I have used a timing light to check the ignition timing and at idle it is showing 0 degrees of advance, and around 5000 rpm only around 18 degrees advance. Am I right in thinking it should be 6 degrees advanced at idle and 24 at higher rpm’s which is pre determined by the ecu ? I’ve changed the knock sensors to make sure they were not faulty which I have heard can effect the ignition timing. I am running a vac line from one runner of my manifold to the ecu for the map sensor. That is most of the background info I can gather, so my main question is: are there any other sensors that must be plugged in which can effect the ignition timing at all ? And is it possible by having the vac line for the ecu coming off one runner causing a pulsed signal it could confuse the ecu, therefore altering the timing by around 6 degrees ? Thanks in advance any help is appreciated.
abf ecu also wants to see coolant and inlet temps to run properly, and i expect it wouldnt be very happy with the vacuum being hooked up to a single runner either. tbh runnign an abf ecu just as an ignition controller isnt ideal at all, you really want a dedicated ignition controller setup which can be properly tuned to suit your setup. the simple way most go about it is a kr ecu and distributor without the vacuum line hooked up, but this isnt very tunable, a megajolt setup for example would give better control
Thanks for your quick reply Jonny! Ahh okay, so you think the water and inlet temps could potentially effect the ign timing ? I wasn’t sure if they were just for the injection side ? I did think the pulsed signal would probably supply unreliable readings, but wasn’t sure if it could throw the timing out by that much. Yeah I think going for a tuneable ignition set up is the way I will go, but I was holding out until i get my hands on some more aggressive cams.
even the mk2 16v ecu needs coolant temp, so I would wire it up for sure, plus inlet temp is worth doing while you're there can strap one up to the filter somewhere temporarily
Hi Jonny, I’m finally getting around to wiring in the water temp and the inlet temp to see if it makes any difference. Do they have to be earthed through pin 33 on the ecu or could I just earth then through the same point that the ecu is earthed ?
ideally earth back to the ecu pin, thats how its supposed to be. but in theory you can earth them anywhere and it'll be fine
Thanks for your reply Jonny ! I wired them both in but they made no difference to the timing at idle. I tapped vacuum pipes into each runner on the manifold, and joined them up to go to the map sensor in the ecu, however I was receiving a week vacuum. About 1/5th of the vacuum a 16v corrado produces. I think this is probably due to losing the vacuum though each runner when each piston is at a different phase. I put non return valves in the line from each runner, which then gave me the correct vacuum and advanced the timing at idle to about 6 degrees, which I think is correct for idle. However, I’m not sure if this will store the vacuum and hold the advance on continuously even on open throttle settings ? I also tried using a common chamber to dampen out the pulse and provide a continuous vacuum but this did nothing. Have you ever come across a solution this this issue? Thanks in advance.
