Shadowdog
Super Member
Hi,
No start on Ford 1985 F800 370 V8 after back fires caused by a broken wire on the dist. pickup coil. My first new replacement pickup coil went bad and luckily bought 2. I rebuilt a spare Impco E series regulator and moved it away from the 425 mixer/carb as it was mounted horizontally right to the 425 (likely so air cleaner would fit) and have it now properly vertical (according to Impco instructions) The spare VFF30 seems to function okay and rebuilt my old one as a spare as it had a ripped black diaphragm. The main diaphragm in the 425 looked good (looked like a fresh silicone one) , but I replaced it anyway along with a new valve.
I missed the idle mixture diaphragm when ordering parts and I checked it and it is not ripped, but stretched a lot on the end at the front of the carb. where the adjustment screw is. Could this cause my no start? The air valve doesn't move on my 425 either on cranking. I can suck on the vacuum hose to VFF30 and hear the gas going to the E series regulator and after pushing the primer hear the gas going to the 425. I tested the E series regulator the way Impco instructions said to. There are 5 diaphragms in total and all are now perfect except that stretched one.
I haven't moved the distributor either so the timing is fine and moving the engine forward and reverse showa the timing chain is very tight as the dist. rotor moves with no hestitation, so very little play. It does have a roller chain stock and 323K KM or 200 Miles on it. Likely the propane and good maint. helped.
I have to move the truck off the street due to coming snow and parts take a long time to come so could I maybe glue some nylon material to my idle mixture diaphragm to stiffen it if that could be the problem.
Thanks very much!
Randy
No start on Ford 1985 F800 370 V8 after back fires caused by a broken wire on the dist. pickup coil. My first new replacement pickup coil went bad and luckily bought 2. I rebuilt a spare Impco E series regulator and moved it away from the 425 mixer/carb as it was mounted horizontally right to the 425 (likely so air cleaner would fit) and have it now properly vertical (according to Impco instructions) The spare VFF30 seems to function okay and rebuilt my old one as a spare as it had a ripped black diaphragm. The main diaphragm in the 425 looked good (looked like a fresh silicone one) , but I replaced it anyway along with a new valve.
I missed the idle mixture diaphragm when ordering parts and I checked it and it is not ripped, but stretched a lot on the end at the front of the carb. where the adjustment screw is. Could this cause my no start? The air valve doesn't move on my 425 either on cranking. I can suck on the vacuum hose to VFF30 and hear the gas going to the E series regulator and after pushing the primer hear the gas going to the 425. I tested the E series regulator the way Impco instructions said to. There are 5 diaphragms in total and all are now perfect except that stretched one.
I haven't moved the distributor either so the timing is fine and moving the engine forward and reverse showa the timing chain is very tight as the dist. rotor moves with no hestitation, so very little play. It does have a roller chain stock and 323K KM or 200 Miles on it. Likely the propane and good maint. helped.
I have to move the truck off the street due to coming snow and parts take a long time to come so could I maybe glue some nylon material to my idle mixture diaphragm to stiffen it if that could be the problem.
Thanks very much!
Randy
