Future vintage car: EFI or carbs better?

Joined
Jun 14, 2011
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Denmark, Europe
Hi,

Imagine the following:

You have the possibility to own an already 30 year old mass produced completely rust free car. The car is going to be your daily driver for the next 30 years and until then the car will be 60 years old.

But you have to make a choice: The car comes with either electronic fuel injection OR carburetors. Which one do you choose and why?

My point of view - although I am just guessing: The EFI is very very reliable as a daily driver in all conditions, summer and winter. The carbs will have more trouble and need more adjustments, tweeks etc. However, there is a chance that the EFI module will start to malfunction since 60 years is a looooong time for electronic components and buying a new module is almost impossible. A carb might need more attention but can always be fixed and repaired.

What is your point of view?

L
 
Vintage carburetor parts in the used salvage yard market are getting harder to source. Most whole unit cores get snapped up by rebuilders and restorers that rebuild, replate, and resell them in the open market. Used EFI ECMs are still plentiful and aftermarket replacement units are still readily available. Other chassis computers like BCMs, ACMs are getting a little hard to source since the pandemic made new replacements hard to source. Carburetor equipped cars are also going to run into increased challenges with today's evolving fuels. Most metro markets will soon have to start selling E15 blended fuels vs those of E10 today and at those blends ethanol can be particularly hard on carb float bowls and components thus potentially increasing maintenance for carb equipped cars.
 
Something that old, probably carb. If a carb has some problems, it still runs, maybe not that great, but at least it runs. If a fuel injection module or critical sensor dies, the car is dead in the water. I'm trying to figure out a running problem in my 86 Volvo. Engine runs fine for 10 minutes, then dies and won't restart until the next day when it starts and runs fine. Fuel injection has a dozen components and sensors and with no OBD, makes things much harder to diagnose and test.
 
EFI can be stupid simple, much simpler than a carb with all its mechanical gadgets, and typically does not require frequent upkeep.. I'd go the EFI route any day of the week.

Are we talking factory configuration? I'd spec a car (or retrofit one with a new system) that needed only the minimum of EFI components-- specifically a speed density system that does not require a MAF. Something like a 1992 Saturn (if we're sticking with 30 year old cars) comes to mind.

Manifold absolute pressure (MAP) sensor, throttle position, coolant temp sensor, air intake temp sensor, and O2 sensor for closed loop feedback, IIRC is all it would really need.

There were a few manufacturers that were steadfastly against MAFs, preferring speed density configurations. Chrysler was one of them and I believe Honda and Hyundai/Kia as well, possibly others. Sadly, more modern emissions requirements ruined all that and forced most engines to transition to MAF based air metering. Not saying MAF setups are inherently unreliable, but you're adding one more sensor to the mix that is not essential to EFI operation.
 
Depends on the car I suppose. While my 94 Z28 EFI is pretty robust and rarely has had any issues even with all the mods I've done to her over the years, my 89 IROCZ wasn't quiet the same. GM used a fairly poor quality MAF in the 86-89 TPI motors and I kept having surging and idling issues despite numerous MAF swaps as well as multiple tuning attempts to remove the problem. In the end I removed the MAF ECM and swapped in a 90-92 ECM that uses speed density, as well as moving the intake air temp sensor to the front of the intake rather than in the intake manifold itself to remove the heat soak issue. I made my own custom wiring harness and put together my own custom tune to run it before I got it all dialed in with proper data logging.

I've also been doing tuning and modding on EFI GM vehicles since the late 90s, so I know a lot more than your average person when it comes to these vehicles. If you already have that type of knowledge about a make (for example, I can't tell you much about Ford or MOPAR EFI of that timeframe since I've never really worked with them) you can certainly keep them running well if you are willing to spend the time and effort to do so. My 89 IROCZ runs perfectly every time I fire her up now and I haven't had to touch the tune in over 2 years. I'm also not running some crazy mod heavy setup for that car either so as long as I keep the parts in good condition there shouldn't be any issues.

Some parts like the 86-89 MAF for the GM TPI motors are only available as rebuilds now and the quality is poor at best. Carb vehicles may be easier to source and are definitely easier to rebuild and work with for your average garage mechanic. I'm also an IT professional so computers and electronics are something I know a lot about, be it for regular systems or for cars. I'd always pick a GM EFI system over anything else since that is what I'm familiar with and know how to work on them.
 
EFI can be stupid simple, much simpler than a carb with all its mechanical gadgets, and typically does not require frequent upkeep.. I'd go the EFI route any day of the week.

Are we talking factory configuration? I'd spec a car (or retrofit one with a new system) that needed only the minimum of EFI components-- specifically a speed density system that does not require a MAF. Something like a 1992 Saturn (if we're sticking with 30 year old cars) comes to mind.

Manifold absolute pressure (MAP) sensor, throttle position, coolant temp sensor, air intake temp sensor, and O2 sensor for closed loop feedback, IIRC is all it would really need.

There were a few manufacturers that were steadfastly against MAFs, preferring speed density configurations. Chrysler was one of them and I believe Honda and Hyundai/Kia as well, possibly others. Sadly, more modern emissions requirements ruined all that and forced most engines to transition to MAF based air metering. Not saying MAF setups are inherently unreliable, but you're adding one more sensor to the mix that is not essential to EFI operation.
Pretty much everything from 96+ requires a MAF due to OBD2 and emissions standards. But at least the MAFs from about 93-94 area are far more reliable than the units that were produced in the 80s. I've never had an issue with the MAF in my 94 Z28 since I've had her yet the 86-89 MAF that the GM TPI vehicles used was barely functional when they were brand new, let alone 30+ years later with rebuilds. After going through probably 5 different MAFs I finally had enough and did a full ECM conversion to get rid of the surging and idle problems on my 89 IROCZ.
 
Carbs aren't good. They only existed at a point in time because EFI didn't.

Might as well ask if we would prefer points/condenser or coilpacks.
 
Pretty much everything from 96+ requires a MAF due to OBD2 and emissions standards. But at least the MAFs from about 93-94 area are far more reliable than the units that were produced in the 80s. I've never had an issue with the MAF in my 94 Z28 since I've had her yet the 86-89 MAF that the GM TPI vehicles used was barely functional when they were brand new, let alone 30+ years later with rebuilds. After going through probably 5 different MAFs I finally had enough and did a full ECM conversion to get rid of the surging and idle problems on my 89 IROCZ.
Not true. Tons of examples of vehicles past 1996 that don't have a MAF sensor. My '07 Chrysler and '15 Kia, as well as an '09 Caliber SRT4 I previously owned were all speed density. I've seen Ford 3.7L V6's that don't have a MAF. Tons of Hondas through the 00's also. With that said, it's becoming more rare as the years go by because of emissions.
 
The injected 460 in my motorhome cranks right up after a winter's rest. I also credit its now-rudimentary EVAP system for keeping the good volatile parts of gas contained for later use.

I would worry about capacitors drifting out of spec and that low-lead solder cracking. Then you get jerks like Chrysler putting potting compound in ECUs making them harder to service, and don't get me started on VIN-tying everything together.
 
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