TBI systems vs DIY vs each other

[SNO*MAN]

I voted on this thread a while back and cannot even remember what I voted for....LOL
The one thing I am convinced of is that the AMC 360 being fuel injected does not pay back the time and money put into it in regards to gas mileage. I think one is way better off doing two things: an overdrive conversion and ignition upgrade to TFI or HEI.

My wagon had fuel injection on it from the prior builder. It ran great but would not pass the "visual "from the smog inspectors. He eventually got way to frustrated and ripped it off and sold it. He put a basic edlebrock set-up back on it. That is the way it currently sits. He said it only got at most 2mpg better ever. I upped that by 5mpg with the OD and TFI conversion combination and when I turn the key it goes VROOM every time.

I will wait until it dies and then install and LS or L9 motor that was designed from the ground up for Fuel Injection. Besides, with the cost of FI, you can pick up a pulled L9 around here for 3k with the 460L or 480L transmission, harness and ECM. One would spend over 7k on an AMC motor to get it to the performance level. WHY?

[Mr2sday]

Ok so I know everyone is dealing with a budget but if you do the research the Edelbrock version really is the best option. The ProFlow 2 system is awesome...have never heard anyone say they have a better throttle response and it starts and runs flawlessly in all weather conditions. Best part is even if your not a tech head and don't fully understand tuning your engine the support team at Edelbrock makes it very easy to get thru.

I would never use a non Multipoint FI sequential system...I jumped to 13-15 MPG on a built 401 that was barely squeezing 10 naturally aspirated.

Worth every penny its sold for...don't think you could ever get the performance, reliability, and fuel economy out of a home made system.

[WasBlue]

I'm getting 8-12 mpg (down from 14 average) from a stock 360 with unknown mileage and no real issues. The truck has 170,000 miles but the engine has been replaced, as I found out when I replaced the transmission. I don't care for the 727 in this truck. My original plan was to adapt a 700R4, but a TBI 350 in front of it seems to be the way to go for what I have planned.

[rockosocko]

MORE resurrecting.
What about 'adapting' the V8 5.2 Grand Wagoneer harness to a 360?

Anyone done it?

Tanks E

[243]

I voted on this thread a while back and cannot even remember what I voted for....LOL
The one thing I am convinced of is that the AMC 360 being fuel injected does not pay back the time and money put into it in regards to gas mileage. I think one is way better off doing two things: an overdrive conversion and ignition upgrade to TFI or HEI.

My wagon had fuel injection on it from the prior builder. It ran great but would not pass the "visual "from the smog inspectors. He eventually got way to frustrated and ripped it off and sold it. He put a basic edlebrock set-up back on it. That is the way it currently sits. He said it only got at most 2mpg better ever. I upped that by 5mpg with the OD and TFI conversion combination and when I turn the key it goes VROOM every time.

I will wait until it dies and then install and LS or L9 motor that was designed from the ground up for Fuel Injection. Besides, with the cost of FI, you can pick up a pulled L9 around here for 3k with the 460L or 480L transmission, harness and ECM. One would spend over 7k on an AMC motor to get it to the performance level. WHY?

I agree with this 100%, I have all the parts ready to go for TBI on my 360 sitting right in front of me in the living room. I am hoping to be in a new house within the next year and will make the LS/4L60 swap and never look back.

The only reason I will will mid-step with the TBI is if I have to drive it more than a year, I hate carburetors.

[firedog]

I've done a TBI system that I pulled off a 91 suburban....re-wired, soldered, cut, heat shrunk, wrapped, loomed. Turned out very very clean looking, been flawless in its performance. With good research and spending some good time making good connections custom to where you want them to lay -- I'd say doing it yourself turns out quite nicely.

On the other hand...I also used Howell TBI system...labeled nicely, works well. I would say it doesn't "fit" as nice as mine, is more expensive, but is slightly more "plug and play" if you don't mind spending a few more $$$.

I've had good success with both of those...

[j2sax]

"Built" for EFI

The below has probably been posted in this thread somewhere by someone else and I believe it may even have been me at some point! Regardless, I don't think we should beat up engine designs from 30 years ago too harshly or to expect too much from just bolting an EFI on a 30-40 year old engine and being disappointed the results do not bring us on par with modern trucks.

That's like the guys that used to bolt on a 4Bbl, intake and headers and be chapped they weren't doing 12's in the quarter miile!

I hear guys all the time saying things like "{} or [] was built and designed for EFI so it will <>". IN reality most of the difference in an engine being "built" for TBI or even Port EFI is in the cam design... overlap and lobe design are the huge influences as to how an engine utilizes the incoming charge and expels it. Remember all piston internal combustion engines are essentially air pumps driven by combustion.

Even between the different types of EFI, whether metered through air volume, density or more electronically (still measuring inputs from these other sources) can be optimized using different cam profiles. The old systems utilizing mostly intake manifold measurements have to have a smooth consistent vacuum signal, whereas more modern electronically driven systems can handle a lot more "lope".

EFI still has plenty of benefits, even if you not getting the 25 MPG you might have expected! Better cold starts is a great benefit. Cleaner oil from less wasted raw fuel is a huge benefit for engine longevity, which is one of the main reasons modern engines easily break 2-300,000 miles. Less fuel in the oil means a greater oil protection on the cylinder walls and bearings which is the main determining factor in engine wear.

I talk to a lot of guys with gasoline powered trucks all the way into the 2000's that are getting 14-15 MPG tops, especially when loaded. Most of my FSJ's are 12-13 range without EFI and overdrive, and I did not spend $50K on mine... or $30K, or $20K.

I think FSJ's do better than these rigs with the same drivetrain (EFI, OD, LS motors swaps) because ours are lighter... it is shocking how much modern trucks weigh, even with their aluminum, high strength (but lighter) steel!

Regardless, it has not been until recent years that gas-powered trucks are getting real world 19-20 MPG thanks to, Variable Valve timing (like doing a cam swap when you hit the gas!), Variable Intake (varies the passage of air through different size/shaped plenums ... like changing intake manifolds when you hit the gas), 7-8-9 speed transmissions, Direct Injection (fuel sprayed directly into the cylinder at over 2000 PSI), multiple camshafts, turbocharging, etc...

What I hear from a lot of guys with these modern trucks are complaints about how expensive their rigs are to fix when they break! Maintenance is so important on these engines that the least bit of abuse can costs thousands. One of the most common failures are the VVT solenoids or other components that are driven by oil pressure. It can run $1500-2000 for the parts and several hundred for the labor if you let too many miles lapse between oil changes. A lot of these guys long for the day when they could pop open their hood, see their engine and understand how to maintain/repair it!

All this to say, don't expect too much from or be too disappointed in the incremental improvements you make with your old FSJ. IF you really want to see bigger improvements, save and spend the equivalent of a few months of truck payments and optimize your engine build with matched components, gears, transmission, etc... and you should be happy with the results. Or do the LS Swap and have the classic look of old iron with more modern everything else.

Just don't be too envious of the guy driving the dual turbo'd, 8 speed, $50K truck... he may be envying you after his first $2000+ repair bill! Happy New Year!

[firedog]

I think (for me especially anyways) that the primary reason for putting a TBI system on a 360 is:

1.) angles and elevation. if you wheel your rig at all, or take it to vastly different elevations, TBI works much better. I've ran off road carbs for years with wheeling trips in Washington and our annual trek to Moab -- and I can definitively tell you that TBI systems work much better on angles and helping to compensate for altitude.

2.) Simplicity of system and ease of repair. Much less complicated and accessible for programming and changes vs. newer more computerized systems, and parts are much much more affordable and available from other existing rigs or from the parts store.

I didn't do TBI to get 50,000 miles to the gallon...but just for reliability and constant performance. Been great, won't look back. The "nostalgia" of running a carb and constantly monkeying with metering rods and jets and bowl floats, and blah blah when I do trips wore off in a hurry. Now I just wheel, enjoy my friends and family, and enjoy cold beverages back at camp!