Ok, this is probably a stupid question, but: What is the advantage of fuel injection over carburetion that people are willing to spend the couple grand to swap?

I have a '79 Chevy truck with a 454 that has major idling issues when it's cold. It's pretty much undriveable without first letting it warm for 5-10 minutes, otherwise the carb ices, etc. I've been told that's a problem with carbureted BB: they take so long to warm up. I can see where EFI on the old truck would be a huge advantage, but what about on a SB?

 

better drivability, gas mileage, throttle responce, and engine longevity... or so i have heard.

 

Like said above,quicker starts ,mileage,driveability,low end torque.

 

All the problems you mentioned go away with EFI. We have 6 cars in the family now excluding the Vette, and I can get into any one of them at any temperature and just turn the key. The EFI adjusts the idle for temperature conditions - important here in New England. Throttle response is much improved also - no bogging because the accelerator pump isn't adjusted correctly or the wrong jets are installed. EFI can also get feedback from the 02 sensors to dynamically adjust the mixture as you drive. It is also tuneable via reprogramming the ECU.

The downside to EFI is that if something goes wrong it can be much harder to diagnose, since everything is inter-related. A stumble at a certain RPM could be caused by one of several sensors not working correctly, dirty fuel injector, faltering fuel pump, etc.

All things considered, I'd say the advantages of EFI outweigh the disadvantages.

DISCLAIMER - I'm a computer engineering type so I have a pretty good understanding of the computer/engine interface. Carbs confuse the hell out of me.

Rick B.

 

hehe. I'm computer science and have no idea what goes on in efi. Gimmie a carb to work on any day!

 

I put a Holley ProJection system in a motor home about 10 years ago. It improved the performance dramatically but the reliability really sucked. Maybe the new ones are better.

 

Yea seen lotsa probs with Holley stuff. When buying Holley, buy carbs! For EFI, use either GM stuff, or if the cash is there, buy ACCEL.

 

That's not true. The old Holley analog EFI had some problems. The new commander 950 is a whole new animal and has been very reliable.

 

Don't forget tuning... I plgg a laptop in uder the dash, read all the sensors, change fuel maps based on feedback, upload new program, and retest. No "black magic" like carbs.

 

The EFI is worth the money if you want the advantages listed above. The carbs are not that complex realy but it does take a little study and experience to fully understand them.

Keep in mind that for the track, a carb is still very good. That is why you see them there all the time.

-Mark.

 

Mark(stingr) thats not true anymore,look at what scooter said,they program there cars right at the track ,make any changes they want without getting dirty.

 

My '79 L82: 225 horsepower, 14mpg highway
A '99 LS1: 350 horsepower, 26+ mpg highway

 

I once had a Renault 30 (a rust bucket with a 2664cc V6 engine that was shared with Volvo & some other company). It had a carb which was set up correctly and had no problems. I then got hold of another Ren 30 (another bag of shyte) & took the entire injection system (Bosch K-Jetronic?) off & fitted it to mine. The difference in running was night & day. Cold starts were no different (the carb handled them OK), but economy improved noticeably, throttle response was immediate & the overal performance increase was hard to believe. Forget the theory, changing a small V6 from carb to FI made such a big real world difference that FI is a longterm aim for the Vette Just got to work out the best (most reliable/tunable/user friendly) system out there & then get the cash to pay for it.....

 

Not to hijack this thread buuuut how much HP can you get out of a TPI?
I have a complete 87 350 TPI out of a Camaro, with mods what can I expect to get?

Steve

 

In the range of 300 stock with good exhaust. With SLP runners and ported intake I think you can get to 400 or so. Scoggin-Dickey got 350 with their intake and Vortec heads.

 

I'm guessing that you would need a larger throttle body also to get to the 400 hp range? I have a TPI from a Camaro also in my basement that I will certainly use if I go with a standard 350 engine for my 79.

Rick B.

 

A LITTLE DIFFERENT, BUT I INSTALLED A CLIFFORD EFI ON A JEEP, AND IT WAS LIKE TRADING THE WIFEY FOR PAMELA ANDERSON IT WAS NIGHT AND DAY DIFFERENCE. IF I HAD THE BUCKS I WOULD CHANGE FROM CARB ON MY VETTE ALSO! BUT I GOT NO BEEFS WITH EM'

 

Just my opinion here, and I am not opposed to modernizing to some degree (OD trannies, throwing out points for elec ign..not an NCRS purist by any means), but I don't get spending big bucks to get fuel injection on a vintage car...If you want fuel injection and all the efficiency/benefits as well as complexity/wires everywhere, go buy a c4,c5,c6...Part of the fun of a classic car is a simple and vintage looking engine compartment. When my 69 or 72 C3 had a fuel related issue, I popped the hood in the garage and tweaked the carb. With my 89 IROC-Z with TPI, I'd pop the hood and scratch my head. Only mod I felt comfortable was to change the air filters to K&Ns.

When people come over my house and I show them my 72, I pop the hood and they see a big chrome air filter, and they say wow, cool..I couldn't imagine popping the hood and the engine compartment looking like my 16 yr old neighbors' 01 camaro. Just my opinion...

 

But that's the cool thing about aftermarket EFI. You can have it vintage looking on steroids. And with the aftermarket systems there are not wires everywhere.

I adapted the L-88 aircleaner and cold air system onto my MPFI system:

 

To each his own... After being into Corvettes for over 20 years, I'm tired of seeing the same old thing. I was -> <- thiiiiiiis close to building a 383 for my car about a year ago. Instead, I wanted to do something different. You can only look at so many smallblock Corvettes before they start to get veeeerrry boring. No, I don't plan to have EFI pay for itself in fuel savings. That's not why I did it. That's just a side benefit. The factor is why I did it.