rockbender
Full Access Member
Like everyone else, I am always in search of that extra MPG and have been going through my van slowly but surely learning more about the IDI engine. I recently replaced my injectors (thanks type4!) and got all my up pipe leaks taken care of so now the turbo is spooling like it should. My next quest will be to get the timing dialed in.
I was curious if the advance arm actually moved or was perhaps seized up so yesterday while the engine was running I pushed it in a little bit and hit the throttle. With the advance arm pushed in, the throttle response seemed a little crisper and the engine quieted down A LOT. It also put out a lot of black smoke too. Pushing in on the advance arm should be 'advancing' the timing, is this correct? I am curious as to why the diesel / PSD rattle mellowed out when advanced? I thought that retarded timing typically didn't have that rattle.
Two other related notes - the advance arm plunger/seal seems like it is weeping a little bit. Since this application is a van, I am not super excited to get started pulling the IP but I assume that I may want to put it on my winter list to either replace that seal or do a new IP.
Second, I don't think I am getting power to my cold start advance. I haven't hot wired it yet to see if the solenoid itself works. It would be interesting to see what the sound difference is - from what I've read, it advances the timing about 2.4 degrees at 1400 RPM.
I didn't have a mirror handy to check any alignment marks on the IP, but I'm not sure that I want to spend any time moving the pump around guessing at timing until I have a meter to do it right.
I haven't driven another IDI for probably 20 years so have no reference point, but I'd sure like to have it with the quiet sound if possible - so much nicer!
I was curious if the advance arm actually moved or was perhaps seized up so yesterday while the engine was running I pushed it in a little bit and hit the throttle. With the advance arm pushed in, the throttle response seemed a little crisper and the engine quieted down A LOT. It also put out a lot of black smoke too. Pushing in on the advance arm should be 'advancing' the timing, is this correct? I am curious as to why the diesel / PSD rattle mellowed out when advanced? I thought that retarded timing typically didn't have that rattle.
Two other related notes - the advance arm plunger/seal seems like it is weeping a little bit. Since this application is a van, I am not super excited to get started pulling the IP but I assume that I may want to put it on my winter list to either replace that seal or do a new IP.
Second, I don't think I am getting power to my cold start advance. I haven't hot wired it yet to see if the solenoid itself works. It would be interesting to see what the sound difference is - from what I've read, it advances the timing about 2.4 degrees at 1400 RPM.
I didn't have a mirror handy to check any alignment marks on the IP, but I'm not sure that I want to spend any time moving the pump around guessing at timing until I have a meter to do it right.
I haven't driven another IDI for probably 20 years so have no reference point, but I'd sure like to have it with the quiet sound if possible - so much nicer!