How long for warm-up?

[ccd3]

Now that everyhting is fuel injection, including my motorcycle, I seem to have forgot about warm-up cycles. Here's my question- how long does it take you guy's trucks to take throttle? My truck starts/idles fine, it just a little fussy for about the first 5-7 minutes. I have a GM performance crate engine w/ a holley and headers. Obviously all the old hot-air stoves are not on.

I'm pretty-sure I have the carb dialed in okay. Gas just dribbles out of the sight glass when I open and the electric choke seems to be closing/opening okay (I'm in Austin Texas- it never gets that cold here).

It just seems to stumble when I moderatley lay on gas. if I punch it- it has no problem. We're talking about after 5 minutes of driving... My temp gauge says things are all warmed up in the engine, but I'm wondering if it just takes more time to get all that steel and aluminum up to temp to properly atomize the fuel.

Before I start tweaking things, I thought I'd ask for your experience.

[mvfd70]

Ahhh gotta love carbs. I'd say just feather the throttle until it gets warm enough and drive it. That's the joys of a carbed engine. Sometimes they don't run for crap until the engine is warm. I used to have a truck that started and ran with no problems at all every time. It was a 68 c-10 with a 250. All factory, manual choke and all. Didn't even have to use the choke a lot of times in winter. I swear every vehicle has it's own personality.

[Joe67]

If it takes more than a couple of minutes, something needs adjusting

[Yukon Jack]

My K5 takes me working the throttle a little bit for about 20 seconds on a 55 degree morning like today - then it will idle just fine. 5-7 minutes sounds way too long. My K20 will fire right up and doesn't take any warming up on a nice day like today to idle and drive fine. In 20 degree weather I do have to keep working the throttle for about 1-2 minutes before it will idle on it's own.

[tavenner13]

i have a demon 850 with no choke or anything and i just turn the key... its like driving a fuel injected vehicle in this texas weather. like the others said 5-7 minutes is way too long

[76bonanza]

There is a big diference between idle fine and able to take a dead stop floor stab also. Mine is drivable with no choke in a few minutes. but it takes a little driving before it is ready for a dead stop burn out.

[70 shorty]

I think a truer statement has never been said than whoever mentioned every vehicle is different. Every one of my vehicles is carbureted and they all do a little different.

[slomotion]

I suspect your experiencing a none-heated intake manifold. I put a crate Vortec in my short bed, and on chilly AM's it would run pretty rough at idle for a long time. I swapped the intake for a heated unit and the problem went away. Seems the atomization at idle gets re-condensed on the cold intake passages and dribbles into the cylinders causing the roughness. At speed it doesn't happen because the fuel vapor is moving pretty fast and doesn't have time to re-condense.

My $.02

[raoul.duke]

I've had the same issues since I swapped my old single plane Weiand intake for a Edelbrock dual plane- i.e. stumble off-idle for about 5-10 mins when cold(idles fine, just stumbles off the line for awhile). Since you're in Austin I doubt it is a cold weather issue.

Richening up the idle mixture screws helped me as every once in awhile I was getting a lean backfire mixed in w/ the stumbles.

Also have been playing around w/ carb tuning- installed a 1" phenolic spacer and all of the off-idle issues went away- it's a LOT more drivable while the engine warms up. Problem with the spacer is that I lost some accel. power so now I'm screwing around w. carb jetting to see if I can get more out of it.

anyways

[Psycho71]

I just fixed this problem on a buddy's Street Avenger, kind of by accident. We were trying to eliminate a slight hestitation. Changed to the correct power valve, no help. Change accelorator pump cams, some help but not quite right. Called the Holley Tech Line, and the guy (Ricky) said to look into the primary bore, barely move the throttle linkage, and gas should squirt from the nozzle instantly upon the slightest movement the linkage. If not adjust the accel. pump linkage until it does. It didn't, we did, and fixed not only the slight hesitation, but also the sluggish warm-up. He can now start his truck and take off before oil even has time to hit the valvetrain good. I guess I got lucky on my Street avenger, and didn't experience either of these issues. And the whole thing on his took us about 2hrs to do. O'Rielly's even had the Power Valve in stock.


Jay