Weird ignition/timing issue

Joined
Aug 19, 2017
Messages
76
Location
Rhinebeck, NY
Hi all this one’s got me stumped. So I’ve got a 74 fj40. I acquired it in non running condition. Anyway, I decided to clean her up a bit a give a good looking over. I got her running and she ran, eh, ok. Checked compression 150 thru all six cylinders. Decided to fix all the oil leaks including vale stem seal. Pulled the head and since it was off sent it off to the machine shop. Everything checked out perfect and he gave it a light resurface. Fit everything back together. Distributor shaft had a lot of play, so new city racer distributor went in. Along with petronix. Also city racer carb so all seemed good. New Toyota wires and plugs and flamethrower 1.5 ohm coil. Stab the distributor in and rotor points just a hair right of #4 spark plug. Oil pressure good. Start her up, set timing to best vacuum back it down from 20 to 18. Tune carb as per fsm. Starts idles great give her gas and pop pop pop. Check for air leaks with carb cleaner and propane… nothing… check accelerator pump. She’s good . Give her gas and pop they the carb. Truck dies. Start her back to check again and she barely wants to run… vacuum gauge is reading “late valve timing”. I check for air leaks and find the mixture screw leaking now. I had a spare “new” parlo carb from amazon and the truck runs better. But still not perfect. Check cap and rotor and rotor looks burned. So something arced. New cap and rotor installed and convert back to points. Me the truck runs almost perfect except for the fact that I have to advance the distributor to 20+ degrees to get good vacuum. Also the vibrating needle on my vacuum gauge is there no matter how many times I readjust the valves . So I’m thinking it’s ignition related…. Buts it’s done this with petronix or points. Also, when first starting the 40 vacuum reads “late valve timing” until she warms up and numbers creep up. Weird thing is before the “pop” from the prior carb vacuum readings were higher and even cold the vacuum gauge would never read “late valve timing”. Any ideas? Sorry for the long post….
 

Pighead

Stop calling it an FJ
Joined
Aug 31, 2004
Messages
9,152
Location
Camino
I was going to say Make sure you're timing to TDC#1...is possible that you're 180* off.
Probably not, but check that again
 
Joined
Aug 19, 2017
Messages
76
Location
Rhinebeck, NY
I was going to say Make sure you're timing to TDC#1...is possible that you're 180* off.
Probably not, but check that again
Yeah, thanks. That’s not it. I set tdc on compression stroke. with valve cover off to confirm that both valves are closed. Thanks though.
 

Pighead

Stop calling it an FJ
Joined
Aug 31, 2004
Messages
9,152
Location
Camino
Yeah, thanks. That’s not it. I set tdc on compression stroke. with valve cover off to confirm that both valves are closed. Thanks though.
Yeah, but somebody had to say it.
So, a new CityRacer dizzy, vac advance i assume?
Checked breaker plate movement with vacuum? Hooked up to the ported vacuum port on the carb?
How about some pictures?
 

pjohnson

SILVER Star
Joined
Jan 15, 2003
Messages
2,849
Location
Idaho
Are you certain your valves are not too tight?
Dizzy is tight, timing staying set?
 

Pighead

Stop calling it an FJ
Joined
Aug 31, 2004
Messages
9,152
Location
Camino
I run mine pretty far advanced, in the 20s BTDC, maybe advance yours a bit and see what happens
 

Users who are viewing this thread

Top Bottom