Jonmueller1

For the last month my 1966/ 425 engine has been losing power and finally quit last week. When I walked away from it in the garage it had a strong smell of unburnt gas.
Previous to this I replaced points,timed the engine and ran gumout through the carb after changing the fuel filter at the base of the carb. After using gumout it ran smooth at idle for awhile. But when fully floored, the car was fluttering at the high end and wouldn't fully wind out. Initially when accelerating hard there is a pop heard thru the air cleaner and I would back off to try again more gradually to get it to accelerate.
When I bought the car five years ago and tuned it up it would really go when floored.
Ideas of what to do:
1) rebuild carb...are there plugs in the bottom of it that have gone bad and are leaky?...is accelerator pump bad??I have already checked for vacumn issues and there appear not to be any.
2) Check fuel filter again, did it go in backwards?
3) replace spark plugs? current ones are five years old
4) Has the coil died?? This is the source of power to the car.
This car has run very well for some five years, I am assuming and integral part has gone bad...any ideas of how to test for different electrical and fuel issues alluded to above?? Many thanks for your help....Regards, JM

joe_padavano

My first reaction is timing chain. If the current chain and gears has 80,000 miles or more on it, consider changing it. The plastic teeth on the stock cam gear wear, which retards the cam and causes loss of power, until the chain ultimately just jumps the gear.

Jonmueller1

Joe, I appreciate your reply. I don't pretend to know alot about these cars. This is the second time I have heard this argument. It is a confirmation of a trait.... My only question...I was once told that the Toronado has a steel timing chain and a steel crankshaft. These are things that I pick up from different people at car shows so I need to confirm the facts....I went out tonight and it started. I have purchased a new coil and new fuel filter and am going to spray starting fluid around the carb gasket to see if there are any vacumn leaks. These are low cost parts and are easy to replace. Obviously the timing chain issue is more major and need to check as to where to get the parts...Many thanks, JM

TripDeuces

My 70 Toronado didn't have steel gears and steel cranks were only in early 68 BBO. BTW, sounds like you have a fuel delivery problem. Weak pump, sock in tank clogged, etc. Coil is easy to check. Have someone crank it while you look at the spark coming from the coil wire (pull it off and put the terminal about a 1/4 inch from a good ground). Spark should be blue not yellow which would be weak. My 66 Rochester has a spike in the fuel inlet so putting the fuel filter in backward is impossible, yours may be the same. Their are 4 plugs in the bottom of a Rochester, 2 primary and 2 secondary. Secondary ones leaking are more common but all can leak. I hit them with a wire wheel/brush and coat them with JB Weld

Jonmueller1

Which side of coil does wire from distributor connect to? Positive or negative? I dropped the mounting bolt while removing old coil and in the subsequent distraction am not sure which side polarity goes to distributor wire..just want to be sure..many thanks, JM

64Rocket

Check the fuel lines from the tank to the front. May have cracks from being 40 some odd years old. Cracks cause leaks to suck air not fuel.
Also replace the condenser in the distributer and the coil. They will run fine, no load, but under a load, problems.
As mention before check the sock on the fuel pick-up.
Gene

BlackGold

I think your carb-cleaning dislodged some speck of dirt which is now making it run super rich. Dirt in the needle and seat will flood the carb, or dirt blocking an air bleed can also screw everything up. Pull the carb and clean and rebuild it before digging any deeper into the engine. (Don't buy a remanufactured carb. Have yours rebuilt.)

bil

Check the oil for a gas smell. It may have gotten thinned out if it is leaking by.Did it smell like the unburned odor was coming from the tailpipes,i.e. it had gone through the engine but not fully burned,or was it more like it was leaking somewhere? Usially the timing gear had plastic teeth on a fibre or aluminium core,the teeth got brittle and came off,making the chain sloppy.Take off the dist. cap,and turn the engine over by hand.If it moves the crank,but the dist does not move,I would suspect the timing gear/chain. ---bil

Jonmueller1

I appreciate all the generous replies to my post. So far I replaced the coil and ran new rubber gas line from fuel pump to fuel tube under passenger side of car. Still backfiring thru carb when you get on it hard. Is it true on a 1966 Toronado that the cam sprocket is plastic?? I can ultimately check this. Am going to replace second rubber hose from steel tube at rear of car to tank. Can also do condenser on side of coil. What is meant by a "sock" in fuel tank...you mean a sort of filter that hangs in there right?
The next step would be to rebuild carburator after checking timing chain and sprocket ..just remove timing chain cover right?........appreciate all the suggestions coming from this site.....THX JM

TripDeuces

The cam sprocket is steel but the teeth are plastic coated which gets hard and brittle then breaks off. This would retard the timing. Backfiring through the carb is an indication of timing being too far advanced. If you haven't touched the distributor it's possible the timing chain could have jumped a tooth. I'd check your dwell also with a meter because changing dwell changes timing.
Sock in the tank is usually a nylon or plastic mesh screen that fits over the pickup tube in the tank. They can get clogged and starve the engine of fuel or fall off causing crap to get sucked into the carb, etc.
Getting to the chain isn't as easy as just removing the front cover. The bottom of the cover has a lip on it that the oil pan seal lies in. To do it correctly you would have to drop the pan, not an easy job on a Toronado. Your front axle goes under the pan. Just check the timing and see where you're at. Dwell first then timing in that order.

redoldsman

I am with Joe on the timing chain. Check you compression when you have the plugs out. Not a simple fix but it is what it is.

bil

As I said,if you suspect timing gear/chain,do as the guys above said,but also try rotating the engine,as in my post above.Just move it a little,you will be turning the crank,the cam and distributor should move at the same time,if there is slack,it should show as a lag before they move-back and forth will show this.To really get to the chain to see if there is slack,you can pull the fuel pump,you can reach in and feel the chain.it should be tight.NOW-anyone correct me on the last statement,I can't remember if it was my old Buick or an Olds that you can feel the chain that way. Good luck with the problem. ---bil

Jonmueller1

Ran the car sunday night. Four runs back and forth. The first two were good where motor responded and wound out in hard acceleration. The last two, it bogged down and then backfired once with a hard push of the petal, then back off and go again slower and it responds. Have to run rubber fuel line from back tire corner to fuel tank..it is old and could be collapsing. The sock could be checked by dropping the fuel tank. I am going to check carburator gasket because it could be leaking. I am trying these things first as they are less complicated and easier than the cam sprocket issue...but I know the truth can hurt. Anyway really appreciate everyone's input..THX JM

bil

From your description I think your timing gear/chain may not be the problem.The motor probably wouldn't have survived.Check the accelerator pump in the carb.Some of the new corn-fed gas reacts badly with the old diaphragms,and causes trouble.Someone makes them for the new fuel,but I don't know who it is. The new crappy gas ruins a lot of stuff,especially small engines,I have seen piles of carbs for lawn mowers,weed wackers,and chain saws,that were reduded to junk by this gas. I am sure there are rubber pieces in the older cars that are effected also.
That bog,backfire thing sounds like the acc. pump to me.Other opinions may vary. ---bil