Tuning a Tri-Carb

[1project2many]

Ok, so it looks like it's not too rich. Did you happen to try to drive when it was acting up or were you just working the throttle while the vehicle was parked? You could try slightly closing the choke when the engine's slowing down to see if it runs better. If that helps then you need to determine if it just runs better at idle or if it drives down the road better, too.

Also could try disconnecting vacuum line to distributor to see if it idles better. Wait until it's hot and acting up though.

I see braided lines on both valve covers. Are those attached to scavenge pipes in the headers?

[DransportGarage]

Originally Posted by tsmith8

Will install new filter tonight. The gas tank was pulled and emptied in the winter. Installed back in and filled with all fresh fuel.

<snip>

Did you look in the tank? Was it clean? Did you pull the sender and inspect the "sock" on the pickup tube?

I've seen multiple fuel filters clog over and over because of debris in the tank. If getting answers to the above questions at this stage is tough to do, you might take your new fuel filter off, cut it open and do an autopsy on it.

[tsmith8]

Tank was rinsed out several times before reinstalling. The new filter is transparent and looks to be all clean.

I took it for a drive to a friends garage tonight. It was about 25 minutes away. About 15 minutes into the drive it started acting up, just wanted to bog down. I kept it going with difficulty, couldn't get 5th gear because i couldn't get the RPM's up enough to keep it running. when i was about three minutes away from the shop it was like someone flicked a light switch. Ran like an absolute dream. ( i don't believe it myself)

I jumped out when i got there, popped the hood and immediately looked at the filter. it had the right amount of gas present. Then i noticed something. I started to get bubbles in the gas coming from the engine side back to the tank side.

So does this mean i have the mythical vapour lock happening???????

Maybe, my buddy is going to re rout the gas line, install a pressure gauge and see what happens.

I own my own business and don't have time to get this done before the weekend. I want to take it to a show on Sunday. Fingers crossed this does the trick.

[tsmith8]

Hey, should of posted this a few weeks ago.

All of the trouble i had, turns out i had a faulty distributor. I still don't fully understand how, but it is working better then ever now.

[Boom]

I have had a points distributor with a bad isolater cause the same problem.

[1project2many]

Thanks for following up. Were you using a stock distributror? An Ebay special?

[tsmith8]

Originally Posted by 1project2many

Thanks for following up. Were you using a stock distributror? An Ebay special?

Thats the worst part. No it was not a cheap or old stock.
It was a MSD 8360
https://www.summitracing.com/int/par...8360/overview/

Not sure exactly how old or how many miles were on it. It was on the truck when i bought it.

Probably going to have it rebuilt. I bought a summit racing equivalent for the short term. I am actually very impressed with the Summit brand one.