@AndyF How do you wire up the second o2 sensor? I do not see that in the instructions
Carburetor, MSD, Holley Sniper EFI questions
- Thread starter Kipprc
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Kipprc
Well-Known Member
Here are the stamped numbers and the cast ID on the carb. I want to make sure I have it identified accurately.
Yes, that's the Edelbrock 1405 manual choke carb.
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You can't use dual O2 sensors with a Sniper but I always recommend adding a bung in each head pipe when you're at the exhaust shop. That way you have an option down the road if you need it. Moving the sensor back and forth can help with the tuning process.
4mulas
Fixem'up
Mattax
Just the facts, ma'am
Its just different.
The box internally builds an electric charge using a capacitor. Then the box releases this charge through the coil for every spark. Look up Capacitive Discharge (CD) ignition.
Points, HEI, Chrysler, Ford etc are inductive ignitions. Power through the coil winding builds a high voltage charge. This charge is released to the spark plugs everytime the connection is interupted.
Whether CD is better depends on what needs to be accomplished. At high rpms, and in difficult combustion environments a CD can sometimes have an advantage when matched with the right coil. It's usually at a slight disadvantage at low rpm, hence most use of multiple sparks at low rpms. (Many people including myself fire up the engines in subfreezing temperatures with no choke and an MSD, so I'd say it works well)
Inductive has potential to be a longer duration spark than CD. This can be an advantage when the flame kernal has difficulty growing as can happen with some of the reformulated gasoline we get. All depends on compression and heads etc etc.
Not really. Did you read or watch the master tech stuff on carburetor fundementals?
There's a big disadvantage of wiring in an electric fuel pump to the original wiring system. It's really not designed for that. Based on what you have expressed as your skill, and knowledge at this point I would not add one until you are ready for the EFI.
That's cool. As long as you know the whole thing will be a journey, including the troubleshooting and tuning, then you won't have the regrets that those that think it (EFI) is a plug and chug. Enjoy the journey.
I do suggest sketching out some goals and plans that will get you to each goal. Right now I see you have threads on suspension, carbs, and other things.
Decide on which targets you want to shoot and knock down first, second, third.
Also if you are willing and have the organization and determination to tie up the car until all the goals are hit.
This is a cause of many project cars not getting complete.
My suggestion is to break up the goals and projects needed to accomplish goal. Then see how it each works in priority and into the calendar. This way you can shake out any issues individually after each project.
Difficult starting is pretty easy to fix then isn't it? LOL
As George Jets pointed out the choke is wired open. Without the choke you will have to finess each start.
First start of the day, will need a richer mix which you are creating by using your foot to physically shoot fuel into the intake.
You will then have to use your foot and judgement to hold the throttle at the correct opening for starting, and keeping it running immediately after starting.
Later starts in the day will need less pump shot to start, and may need more initial throttle opening. Even with no choke sometimes its neccessary to hold the throttle slightly open for hot starts.
First start after sitting for more than a day will vary with climate, where the car is, and whether there is a vapor capture system.
That said, in general, the most volatile components of the fuel will have evaporated out of the intake and to a lesser extent, the bowl. This is like trying to start a campfire without tinder. So it takes a little more effort. Even with a working choke a few pump shots are often needed. Really no big deal once you're used to it.
Hope its wired to the fuse box.
You're tackling a BIG Project. Get a notebook, file system, clipboard and wrtie stuff down. Coming up with a note system that works for you can take some time. I use all the above plus spreasheets on the computer. Again, whatever works for you so you can find the info again. Also every time you write stuff down it will help you remember. If you watch videos, take notes.
Seems like this is a good starting point! Review what George wrote. Then look in the shop manual and the master tech to get familiar with any terms that don't make sense. Still questions after that; then post them in one of your carb threads.
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Kipprc
Well-Known Member
A lot to unpack there. I appreciate the info that you took the time to post. The concurrent running threads is by design. I know from previous experience that sometimes very knowledgeable people only check certain parts of forums. Instead of running one project thread, I have found the shotgun method is the best approach. I will figure out the carb on the way to EFI. I have a white board going and a couple hundred pages of install instructions that have digging into since I purchased the car. Goals were set before the car got delivered. The radio was done properly. No worries there. The suspension is almost done. Thats more about time at this point, but it should be done this week. I'll get to my end goal, it just takes time.
I had the edelbrock 1406 on it was pretty solid. I knew nothing about carbs and was able to rebuild it and tune it and it was rock solid.
I switched to the sniper set up and it has worked great. I run it with a gm hei ignition without timing control and most problems I’ve had were due to myself not following the directions. Maybe I’m lucky, mine starts hot or cold, doesn’t stall or have problems. I drive it everywhere. I didn’t shield my wire harnesses or join a bunch of groups to figure out how to make it work. I don’t tune it and have never plugged it in to a computer to check the data logs. I sure I’m leaving a bunch on the table by not dialing it in 100% but for what I use it for it works great.
All that said, I think a carb would be easier for someone with limited knowledge or skills. With a good ignition system all you have to worry about is fuel. Fuel pump feed the carb, carb feeds the engine. Not much to it and fairly easy to figure out. Not saying you don’t have skills to figure it out but I think carbs are easier. Either way, both are going to require educating yourself to run either system.
I switched to the sniper set up and it has worked great. I run it with a gm hei ignition without timing control and most problems I’ve had were due to myself not following the directions. Maybe I’m lucky, mine starts hot or cold, doesn’t stall or have problems. I drive it everywhere. I didn’t shield my wire harnesses or join a bunch of groups to figure out how to make it work. I don’t tune it and have never plugged it in to a computer to check the data logs. I sure I’m leaving a bunch on the table by not dialing it in 100% but for what I use it for it works great.
All that said, I think a carb would be easier for someone with limited knowledge or skills. With a good ignition system all you have to worry about is fuel. Fuel pump feed the carb, carb feeds the engine. Not much to it and fairly easy to figure out. Not saying you don’t have skills to figure it out but I think carbs are easier. Either way, both are going to require educating yourself to run either system.
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