Unhappy 40-troubleshooting help?

[78crzr]

Left the house to take the 40 to Coffee & Cars this morning , but only got about 1/2 mile away before it started running rough as hell, really low on power, and back firing through the carb about every 5-10 seconds. Made it back to the entrance of our neighborhood and it died and wouldn’t restart. It cranked but that was it. Also noticed a few puffs of blue smoke coming from the tailpipe when I attempted to start it. I smelled fuel so don’t think it was fuel starved. Oil pressure and engine temp. were normal.

Any ideas as to what it may be? Thanks in advance.

 

[Living in the Past]

Check for any hoses that may come loose. I would also verify the time. Distributor came loose for any reason could cause this. If this is a 78 it should have a pointless distributor other point gap could also cause a weak spark which leave unburned fuel.

 

[78crzr]

Check for any hoses that may come loose. I would also verify the time. Distributor came loose for any reason could cause this. If this is a 78 it should have a pointless distributor other point gap could also cause a weak spark which leave unburned fuel.

Appreciate the suggestions, I checked hoses and distributor and all seem fine. It’s a ‘76. A little black inside the carb. but kind of expected that after this morning’s fun. Unfortunately can’t check timing since it won’t fire.

 

[Mark Jennings]

Loose wire to distrib or ignition switch. I’ve had it happen on several 50 plus YO vehicles. Toyota is no exception.

 

[Chungas Revenge]

I can’t see where you 12v switched is coming in from for your DUI. But, this connection, pink wire in pic, is 12v switched for the DUI. That connection is a single point failure. Easy to confirm or deny as a prospect culprit for your issue.

 

[mattressking]

Fuel looks rather low in sight glass...

1. Is the fuel cut solenoid clicking repetitively with key on when you disconnect and reconnect cable?
2. Is fuel in middle of sight glass?
3. Does choking the engine help or no major change?

 

[78crzr]

Thought I’d share a belated update in case anyone experiences the same issues. Turned out to be the distributor, which was advancing way too far, like 15 degrees. It was only a few years old so wouldn’t have expected that, but it happened. Brand new DUI installed. It’s got a noisy counterweight, which I don’t remember the old one having, but my mechanic that ordered/installed it said everything checks out fine, so good to go.

Thanks again to those that commented and helped to provide troubleshooting assistance.

 

[whitey45]

Noisy counter weight? Who told you that?

 

[78crzr]

Noisy counter weight? Who told you that?

My mechanic. Weights, counterweights, whichever ones are contained in the DUI Distributors. I’m no distributor expert, obviously. Have owned many classic cars but never had distributor issues….until I did!

 

[Paul_A]

This guy does a pretty good job explaining it. It just goes to show that you can learn someting new every day.

 

[whitey45]

They have different spring tesions to dial in the timing curve. Hope he didn’t recommend a new distributor? Springs and weights are replacable!