Holley 750 is Cold Blooded

[rose359]

I recently purchased a 1988 Scottsdale 3500 with a Holley 750 carburetor on a 454. The previous owner told me that the EFI was burned when he bought it. He put the Holley on an intake manifold from a 1966 396. He put in a new steel fuel tank, fuel lines, and high volume fuel pump. The choke is manual. It starts fine, but it is hard to keep running while the engine is cold. The choke seems to be working, but I may prefer an automatic choke. The choke requires quite a bit of force to close, which flexes the plastic dash. Any recommendations?

 

[tpass]

I would check the the Air/fuel ratio and see if you are running lean, may need different jets or power valve, no way to know what engine build that carb was set up for before it was put on there. (unless you've already looked)

As for the choke, lube up the cable and make sure there aren't too many sharp bends or kinks, especially at the end near the carb.. sometimes the solid steel cable gets buggered and causes friction.

Smarter carb peeps will chime in soon

 

[Donald Mitchell]

I'm sure you can get an electric choke from Holley.

 

[RichLo]

There are plenty of tuning instruction out there for Holley's. It sounds like your high-idle isnt high enough or disactivated completely.

You may need to break it apart to see what jets are in it also. Most people just slap a carb on, adjust idle vacuum and run it. But most Holley's are factory tuned for a stock 350ci engine as thats the most common. Once you get to the extremes (454 or 4.3) you'll need to start swapping hardware inside.

 

[Schurkey]

Perhaps a moderator will move this thread to the LSX + Carb Swap sub-forum.

Depending on which model of "Holley 750", an automatic choke option would be best. Manual chokes are early-1900's technology, auto chokes have been reliable since the 1950s.

Be aware that there are 4 adjustments to an automatic choke that have to be correct. Once that's achieved, starting and warm-up should be SEAMLESS from -20F to operating temperature, just like fuel injection except with higher idle speed, and probably more emissions especially during warm-up.

The Holley electric choke kits mention one of the four adjustments, and TOTALLY IGNORE the other three. Which pretty-much guarantees that the choke won't work right, and the auto-choke system gets a bad reputation as a result.






"I" would be keeping an eye out for a Treasure Yard 454 TBI to steal the Fuel Injection/computer system from.

 

[Erik the Awful]

I gotta say, a Holley Sniper is easy to install and run. The refurbished units are under a grand. I bought mine when they were down around $800. Comparing $800 for an EFI to $450 for a carburetor that you'll constantly be tweaking, and it's a no-brainer. At $1000 it's still a great deal.

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