Just when I think I have my carb dialed in, I don't

[MisterB]

I have an Edelbrock carb with electric choke. I have adjusted the idle, fast idle, and the fuel mixture screws on the front. The truck runs great, but I have an issue with cold start idling. Here's what it does when cold and starting first thing in the morning. This is when it's between 20-45 degrees F:

Slowly depress and release gas pedal once. Turn key to on position and wait a few seconds. Turn all the way and crank. It normally fires right up. It then starts to sort of idle rough, but sometimes if I leave it be, it'll start to slowly creep up the fast idle all the way to the max I have it set. Once I've let it warm up enough, I blip the throttle and the fast idle comes off and the truck idles fine and I can drive away and all is well. BUT, sometimes after I start it and it rough idles, it'll die before it has a chance to fast idle. If I try to start it again, the truck acts like it's flooded.

Any idea how to get this dialed in once and for all?





Sent from my SM-N975U1 using Tapatalk

 

[SquareRoot]

I have an Edelbrock carb with electric choke. I have adjusted the idle, fast idle, and the fuel mixture screws on the front. The truck runs great, but I have an issue with cold start idling. Here's what it does when cold and starting first thing in the morning. This is when it's between 20-45 degrees F:

Slowly depress and release gas pedal once. Turn key to on position and wait a few seconds. Turn all the way and crank. It normally fires right up. It then starts to sort of idle rough, but sometimes if I leave it be, it'll start to slowly creep up the fast idle all the way to the max I have it set. Once I've let it warm up enough, I blip the throttle and the fast idle comes off and the truck idles fine and I can drive away and all is well. BUT, sometimes after I start it and it rough idles, it'll die before it has a chance to fast idle. If I try to start it again, the truck acts like it's flooded.

Any idea how to get this dialed in once and for all?

Sent from my SM-N975U1 using Tapatalk

Yes. It's called fuel injection. That's why every car manufacturer uses it.

 

[Matt69olds]

Set the choke heater just a little bit to the leaner setting. I’m guessing what your experiencing is the engine loading up before the choke starts to open.

with the engine completely cold (let it sit in overnight) adjust the choke heater do the choke flap is almost completely closed. It may take a couple cold starts to dial it in.

 

[MisterB]

Set the choke heater just a little bit to the leaner setting. I’m guessing what your experiencing is the engine loading up before the choke starts to open.

with the engine completely cold (let it sit in overnight) adjust the choke heater do the choke flap is almost completely closed. It may take a couple cold starts to dial it in.

Thanks. I'll definitely try that.

Sent from my SM-T720 using Tapatalk

 

[MisterB]

Set the choke heater just a little bit to the leaner setting. I’m guessing what your experiencing is the engine loading up before the choke starts to open.

with the engine completely cold (let it sit in overnight) adjust the choke heater do the choke flap is almost completely closed. It may take a couple cold starts to dial it in.

I went out this morning to adjust the choke. The truck was stone cold, and it was about 44 degrees F.

I removed the air cleaner, and noticed the choke was fully closed. I pressed the accelerator once slowly and released slowly. The choke then opened about 1/4". I decided to adjust the choke at that point so it would shut. I then turned the key and it fired right up and idled perfectly fine. If anything, I may want to adjust my high idle a little higher, but other than that it seems to have improved things.

Does it sound like I'm on the right track?

Sent from my SM-N975U1 using Tapatalk

 

[Colin]

Slowly depress and release gas pedal once. Turn key to on position and wait a few seconds. Turn all the way and crank. It normally fires right up. It then starts to sort of idle rough, but sometimes if I leave it be, it'll start to slowly creep up the fast idle all the way to the max I have it set. Once I've let it warm up enough, I blip the throttle and the fast idle comes off and the truck idles fine and I can drive away and all is well. BUT, sometimes after I start it and it rough idles, it'll die before it has a chance to fast idle. If I try to start it again, the truck acts like it's flooded.

Any idea how to get this dialed in once and for all?





Sent from my SM-N975U1 using Tapatalk

This is exactly how my truck behaves with cold starts and its still equipped with a Quadrajet (except for the acting flooded part).

 

[Backfoot100]

I went out this morning to adjust the choke. The truck was stone cold, and it was about 44 degrees F.

I removed the air cleaner, and noticed the choke was fully closed. I pressed the accelerator once slowly and released slowly. The choke then opened about 1/4". I decided to adjust the choke at that point so it would shut. I then turned the key and it fired right up and idled perfectly fine. If anything, I may want to adjust my high idle a little higher, but other than that it seems to have improved things.

Does it sound like I'm on the right track?

Sent from my SM-N975U1 using Tapatalk

Sounds about right to me. 1/4" is too far open when stone cold.
1/16"-1/8" is how I've always set em.

As long as it opens up as it warms then you should be good.

 

[MisterB]

Sounds about right to me. 1/4" is too far open when stone cold.
1/16"-1/8" is how I've always set em.

As long as it opens up as it warms then you should be good.

I'm back to having problems again. Tried starting it this morning cold. It fired right up, but then stumbled and died. I held the choke open with a screwdriver to block the flap and started it to clear out the fuel or it would have stayed flooded for a while. It idled just fine and I eventually removed the screw driver.

I decided to increase the regular idle a bit. Not the cold idle, but the regular idle. I'm hoping that'll help.

I'm noticing it sits there and idles for several minutes at a lower idle, and then slowly creaps up to a fast idle and stays there unless I blip the throttle to take it off high idle. Why does it take several minutes to creep up to cold high idle? Shouldn't cold high idle come on sooner?

Sent from my SM-N975U1 using Tapatalk

 

[Backfoot100]

I'm noticing it sits there and idles for several minutes at a lower idle, and then slowly creaps up to a fast idle and stays there unless I blip the throttle to take it off high idle. Why does it take several minutes to creep up to cold high idle? Shouldn't cold high idle come on sooner?

Sent from my SM-N975U1 using Tapatalk

Yes the fast idle shouldn't take that long to come in. Setting the choke should set the fast idle cam so its in fast idle as soon as it starts.

I'm getting better with QJ's and pretty good with Holleys but never messed with a Eddy. Not sure what to tell you about that unfortunately.

 

[MisterB]

Yes the fast idle shouldn't take that long to come in. Setting the choke should set the fast idle cam so its in fast idle as soon as it starts.

I'm getting better with QJ's and pretty good with Holleys but never messed with a Eddy. Not sure what to tell you about that unfortunately.

I think there's a possibility I have things adjusted to be too rich. I'm going to lean things out and see if that helps. It just seems like it's really easy to flood this truck

Sent from my SM-N975U1 using Tapatalk

 

[MisterB]

I still can't seem to get this dialed in. I took the truck for a drive yesterday to let it heat up, and then adjusted both screws on the front of the carb to lean it up as much as possible (turned each to the right until idle decreased, and then backed off a turn and a half or so). Let it sit overnight and then pressed and released the accelerator once slowly and started it. The truck fired right up, but then idled rough and died.

Any other ideas?



Sent from my SM-N975U1 using Tapatalk

 

[MisterB]

I just tried something, and it seems promising. I adjusted the choke again. I think I had it turned too far to the right so it was set to close, but then too far past closed, and so it wasn't opening the choke properly, and therefore was flooding it when it first fired up.

Sent from my SM-N975U1 using Tapatalk

 

[Jt1776]

Buy a holley and you will be very happy. They have a cheaper brand called quick fuel. I replace my edelbrock with a quick fuel and it has been heaven, starts every time.

 

[MisterB]

Buy a holley and you will be very happy. They have a cheaper brand called quick fuel. I replace my edelbrock with a quick fuel and it has been heaven, starts every time.

Well, I might one day if I don't get this sorted out, but I figured out some other good stuff today and I may have fixed it

Sent from my SM-N975U1 using Tapatalk

 

[MisterB]

I got my vacuum gauge connected properly, and I was able to move it from the red zone to the green finally. The idle was way too low and the fuel mixture was off. The truck seems to be liking this. I'll see how it idles in the morning, but it looks very promising

You must be registered for see images attach

Sent from my SM-N975U1 using Tapatalk