Just checking in - new project started - EFI on '82

Ray Cecil wrote

I think the argument for carb vs efi is pretty well argued online. I think there are a lot of dyno tests that prove that self learning EFI does create an engine that produces less harmful emissions at any rpm, and better fuel economy. If carbs were better than EFI at emissions and mpg, they would be standard on modern vehicles. They aren't, so there is good reason to trust carbs are less efficient with emissions and mpg.

I agree with you about emissions being better with EFI, which is the main reason why all modern vehicles today have EFI. But there shouldn't be a big difference in fuel economy.  I also agree that EFI is more flexible for altitude changes, but I think most people get too hung up on that.  It's not like a carburetor cannot handle it at all.  Like grumpin said, vehicles with carburetors have been going up and down mountains for years, and no one was on the side of the road changing jets or re-tuning their carburetors.

The only real reasons to replace a carburetor with EFI is for better emissions and the ability to self-tune.  In exchange, you get a lot of wires, sensors and a computer to make that happen.  That being said, no one ever says they want a fuel injection system for "better emissions." Instead, I often hear things like "better cold starts" and "better performance" as reasons why.  Those are simply not valid reasons to replace a carburetor with a fuel injection system.  The truth is, if you replace your carburetor with an EFI system and you get "better cold starts" and "better performance" or a big increase in fuel economy, then something was not right with your carburetor.  

I would not replace an EFI system with a carburetor, either.  BOTH systems work great when they are dialed in and functioning correctly.

Good luck with your project, CountryBumpkin.

Hey guys, Mike may not want his thread taken up by a discussion on the merits of carbs and EFI.  But we've done a good job of that, and I'm as guilty as any.  

We have another thread called Computerized Fuel System Documentation Musings where we could take the conversation.  Or, we could start another thread with any title we want.

Mike - Do you want us to take our musings elsewhere?  I can move the various posts if you'd like.

Ray Cecil wrote

grumpin wrote

I don’t think you need to re jet for 8-9000 ft elevation unless you’re going to stay there.

I re jetted my Holley for 4100 ft because I live at that altitude.

We were going up to the summit of Mt. St. Helens salvaging timber after the eruption with carbureted trucks.

Reminds me, I had a newer bullnose 4x4 company truck, with a lift in the bed so we could get up and work on the Skycrane.

I think the argument for carb vs efi is pretty well argued online. I think there are a lot of dyno tests that prove that self learning EFI does create an engine that produces less harmful emissions at any rpm, and better fuel economy. If carbs were better than EFI at emissions and mpg, they would be standard on modern vehicles. They aren't, so there is good reason to trust carbs are less efficient with emissions and mpg.

EFI is more flexible for altitude changes. EFI does have a performance edge, but only slightly vs a properly tuned carb. The performance edge is basically marginal. The biggest CON for EFI is the price point, and some think the complexity. However, companies like Fitech are producing EFI kits that are very competitively priced, and easy to install. Fitech has forced Holley and MSD to have more competitive pricing on their EFI systems. Price will come down as more people switch.

It all boils down to what the individual prefers, and the purpose of the vehicle. I COMPLETELY understand the simplicity of a carb. But I also like the idea of the modern technology inside of EFI.

Yes indeed, just commenting on jetting.

Doesn't matter - where the discussion takes place.

My decision has been made. Money spent.

That looks nice! Anxious to hear how it works. As said, it’s the cost that stops me!

Just to report back - I have the Atomic installed now and can tell you that I am very impressed.

I have not done any "tuning" other than to set my initial timing at 12 BTDC, the full Advance at 34 degrees (all in by 2400 rpm), and the idle speed at 750. Everything else is basically at the default settings. There's a bunch more tuning that can be done (Pump squirt, Power Valve Enrich, A/F targets).

On my first road test, I was very impressed. The truck starts immediately and idles nice. There is no tip-in hesitation (I always had a little tip-in hesitation with the carb), strong acceleration, feels better than ever and sounds better than ever. The air-fuel ratio is 14.0 to 14.7 throughout the range. I have some loose cargo in the bed so I didn't try any full throttle standing starts, but doing rolling WOT feels strong.

I do have one issue to investigate.
The fuel pressure is too high. i have the pressure regulator set to 48 psi. At startup the pressure on the display screen (and the mechanical gauge) show 48 then after a little bit it creeps up to 80 or 90 psi. The higher pressure is not causing any run problems and the A/F ratio is staying right at 14.0 - 14.7 (I would even know about it without the display/gauge telling me). But it's not supposed to do that.

I called MSD and their Tech said either I have a restriction in the return line or the pressure regulator is acting up. I'm going to run a temporary return fuel line from the regulator outlet port to a gas can, to see if the problem is in the return line to my tank or not. If it still builds up too much pressure, the Tech said I can easily disassemble the Regulator and see if there's some trash inside. Googling this issue and looking on YouTube I don't see anyone else mentioning this problem, so I guess i'm the first (lucky me). But I expect it should be easy enough to fix.
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BTW - on cost; I have about $1,500 in it with the Atomic kit, additional fittings/hardware, having bung fittings weld to fuel tank, the MSD distributor "adjustable rotor" kit, new plugs and wires. There's always a little more $ needed than just the cost of the EFI kit. But I've been through several carbs too over the years trying to get the right one (Holley 750, Holley Street Avenger, Quickfuel HR, multiple rebuild and tuning kits, etc.) so if I started with the EFI I probably would have spent the same amount of money in the end. :D

Well done!  That's good news.