Hi guys!
I've searched the boards for help with this problem, but haven't found any conclusive answers, so either I'm dumb and can't do a good search or it hasn't been brought up .

Ok, I've got a 350 set up with the Holley Systemax II package (most of the stuff about the motor is in my sig) and I'm running a 600 cfm VS Holley carb with electric choke on the motor for now since I had that carb off of my 305. Anyway, when the weather is cold the car is almost impossible to start. You can crank it over and get a couple chug-chugs out of it and IF you catch it EXACTLY right and feather the gas pedal you can get it to keep running, otherwise you've gotta pull all the plugs and dry them off with compressed air because they're soaked with gas. This is without the electric choke set up (I just turned it all the way lean so that it never engages) because the one time I tried to use the choke the car started, ran for 5 seconds, died and had flooded out so bad that I had to replace the plugs Anyway, my big question is how do i set the choke up on this carb so that it will do its job properly, allow me to start the car and not flood it out? It's not like the carb is huge and always floods the motor because under cruise conditions I tend to run a little lean (need to try yet another power valve I think). Anyway, sorry for how long this post is but any ideas on what I could do to help get rid of this problem would be very much appreciated. Thanks so much!!!

-Paul

 

Anybody have any ideas? Someone must know how to set the choke up properly! Thanks in advance!

-Paul

 

Anyone have thoughts on setting up the choke? One other thing the car does is that when the engine is warm and the car sits for 20-30 minutes you have to crank it a lot to get it to start. If you start the car immediately after shutting it off it'll fire right up, and if you wait 45 minutes or more it'll fire right up also. I've been told that I need a heat insulating spacer between the intake and the carb, and I think that's true, especially since it doesn't do it anywhere near as bad when the weather is cold. Any help or suggestions with any of this would be very much appreciated. Thanks!

-Paul

 

its a holley man, trust me youll have to just mess aroudn with the choke and all. i had a 750 dp and now im going to edelbrock pro flor efi because i live in PA wher we gery EVERY type of weather and i hated dealign with that crap. Oh by the way i was running 10 degrees timing with the vacuum disconnected at 800 rpms with the medium weight advance springs if that helps you out. also be sure that in the winter you change to a hotter range plug that holds the heat like a r45ts, i run r42ts's with the nitrous and all that i have, but in the cold weather it was a total pain in the butt to get started unless i had starter fluid. my advice is save up for EFI as soon as you can and maybe get a TPI unit off of ebay for like 200.

 

Well, I do have plans for a Holley Stealth Ram EFI setup at some point down the road (mentioned in my sig) but that probably won't be for a while so I'm trying to get the carb working as good/efficiently as I can for now. Overall the car runs pretty well and the carb doesn't require much messing with, it's just this one problem that gets to me. I have a friend who is going to let me borrow a 750 from him (Holley recommends a 750 with the Systemax II package I have) and I'm going to see what that does for me. Anyway, thanks for the suggestions and if anyone else has any thoughts please let me know!

-Paul

 

Adjust the choke thermostat such that with the engine cold and in an environment of about 70 degrees F, it is just beginning to close the choke. That is, if it's any cooler than that, you'd want the choke to close; any warmer, you don't really need it. Then tune it from there. If it still has trouble with running lean when cold, turn it a little in the "rich" direction; and if it has trouble with running rich when it's warm, lean it out.

It always amuses me to see people bash carbs about how they require constant fiddling, don't work in the cold, etc.; I guess these folks just conveniently forget that their great-grandma probably drove her car in the same weather they have now, with a carb on her car that probably had a much more crude choke system of some sort than a modern electric one, for years and years and years, and it worked fine for her without her having to do much fiddling with the carb. These people must think everybody just parked their cars for the winter or something, just because they can't figure out how to tune a carb. That's hilarious!

As far as the hot start problem, that's caused by a fuel leak from the carb into the manifold. I'd suggest new power valves especially the one in the primaries. Just one single backfire (typical cold start problem) can take a PV out.

 

my carb worked great after tuning it up, it took a bit since i was used to TBI when i coverted, but i overcame it. i suggest getting a holley tuning book maybe, they sure did help me out alot with mine. as far as the powervalve is concerned, yeah def relpace that, even if you have the PV blowout protection on there liek i ahd on mine i still shot a few of those. I have alot of holley tuning items such as complete jet kit, and alot of other items that id like ot sell if you know anyone thats interested.

joe

 

Thanks for all the help guys, now I've just gotta find a place that's 70 degrees to set the choke up, cuz I know my garage back home in Maine with no heat is not gonna be 70 degrees again for a few months lol On the power valve, I have replaced it (in the process of trying to get rid of the flat spot in highway acceleration) and I haven't had any backfires since then so I'm pretty sure the PV is fine. I was told that when the engine and engine compartment are very warm it can cause the fuel to start to boil in the bowls and force some out into the intake, creating a minor flooding condition, and that if I put a heat insulating spacer between the intake and the carb that it would help out with this situation. Anyway, at least I've got some more things to try now, thanks so much guys, I really appreciate it!

-Paul