Hi guys, is the timing extremely retarded on these buses to extend engine life? Ive got a '75 cali 1700 Fi which is set to 5 degrees atdc which seems very late to me and when fiddling with my timing she sounds so much happier when advanced to btdc. Im no ignition expert coming from a diesel/plant background but im sure they taught us in college that a few degrees btdc allowed for the 30 degrees of crank movement required for full combustion to power the piston down. Any thoughts?
Are you sure you've got the number right? Mebbe some weird vac-only dissy. As you say, anything after TDC will light the mixture as the pistons going down on the power stroke: you're just wasting power and the engine will feel like a slug.
Hi Just started a thread asking for advice on my 1700 automatic. Haynes says 10 ATDC for an auto and 5 ATDC for a manual. That's for Yank vans. European ones: 7.5 BTDC No explanation, wonder if anything to do with emission control?
The original american distributor will be dual vacuum DVDA with two vacuum hoses which ends up with the ATDC setting for idle with low emission. Once the revs pick and the vacuum signals switch over up it sneaks back to btdc like normal when nobodys checking the idle. Like my 307 diesel which idles at 800 rpm if you leave it but it takes a few seconds to drop from 1000 rpm after you let your foot off the clutch. If there is only one hose (Single Vacuum Dual Advance SVDA) or no (Beetle style for light car..)vacuum hose on the distributor then setting would be7.5 btdc .
