tvrrproto48
Registered User
I have read at several blog sites, "book specification for dynamic timing is 8.5* BTDC". Where is this 8.5 coming from.
I have an 85 F250 with ATS turbo I inherited from my dad. 132k original miles. It smokes a lot and was a little difficult to start. I replaced injectors and it ran smoother but still cranked a lot to start not as much when hot but not like the single revolution required from my Mazda diesel.
I replaced the glow plugs with 12G as I was told they are self regulating and won't swell. With less than 100 miles since doing this the engine died on a trip to town.
I replaced the ip but still would not start. Replaced all rubber hoses within the engine compartment. Replaced the fuel return with a 7.3 kit. I had set the timing with the cast marks placing the new pump in the same position as the old. Have finally stopped all air leaks. After 2 or 3 cycles of 30 second cranks it will start but only with the throttle to the floor and rpm's have to be held above 1k for a minute and slowly lowered or it dies.
Bought a DTI 3300S timing setup. Using the pulse adapter and timing light I set the pump to "8.5*". It is still hard to start. It no longer has a lop at idle and runs up smoothly but still has a lot of smoke even after fully warmed. Shutting it down and immediately restarting still has to crank with at least half throttle and patience. I have seen this 8.5 thrown around on the web for years. Where did it come from? The factory manual says between 4* to 7* depending on elevation and cetane. That is for magnetic probe which I haven't tried yet because it doesn't come close to fitting the hole and with the luminosity probe.
I'm sure at this point it is a timing issue. Just not certain which way to move it. Oh and the 12Gs that never can swell. With less than 100 miles 2 okay, 1 split, 2 bulged and the other three still trying to get them out of the holes. Will have to pull the heads and break off the tips to get them out.
Jeff
I have an 85 F250 with ATS turbo I inherited from my dad. 132k original miles. It smokes a lot and was a little difficult to start. I replaced injectors and it ran smoother but still cranked a lot to start not as much when hot but not like the single revolution required from my Mazda diesel.
I replaced the glow plugs with 12G as I was told they are self regulating and won't swell. With less than 100 miles since doing this the engine died on a trip to town.
I replaced the ip but still would not start. Replaced all rubber hoses within the engine compartment. Replaced the fuel return with a 7.3 kit. I had set the timing with the cast marks placing the new pump in the same position as the old. Have finally stopped all air leaks. After 2 or 3 cycles of 30 second cranks it will start but only with the throttle to the floor and rpm's have to be held above 1k for a minute and slowly lowered or it dies.
Bought a DTI 3300S timing setup. Using the pulse adapter and timing light I set the pump to "8.5*". It is still hard to start. It no longer has a lop at idle and runs up smoothly but still has a lot of smoke even after fully warmed. Shutting it down and immediately restarting still has to crank with at least half throttle and patience. I have seen this 8.5 thrown around on the web for years. Where did it come from? The factory manual says between 4* to 7* depending on elevation and cetane. That is for magnetic probe which I haven't tried yet because it doesn't come close to fitting the hole and with the luminosity probe.
I'm sure at this point it is a timing issue. Just not certain which way to move it. Oh and the 12Gs that never can swell. With less than 100 miles 2 okay, 1 split, 2 bulged and the other three still trying to get them out of the holes. Will have to pull the heads and break off the tips to get them out.
Jeff