Help me out on TBI to EFI

[AaronW]

Hi all:

So I've got an 89 454 crew cab, TBI. I'm doing the body work, and a machinist I know, has the engine. We've been discussing either going back to a quadrajet, or going to an EFI system. As I see it, the advantages of the 4 bbl carb are that the truck won't have any computer in it at all, anymore, and the way parts, supply chains, etc... are these days, that sounds kinda appealing. Don't want to get too political here, but the idea of being free of computer dependency soudns pretty good these days. It's pretty rural out here, and I kind of like the idea of being able to fix my carb if I get stuck 100 miles from anywhere, while I'm ice fishing. If my efi craps out on me in that scenario, I could be in real trouble.

On the other hand...

It looks like I could get some improved mileage with an EFI system, and maybe easier starting, too, and since gas just broke 5 bucks around here, for the no-ethanol stuff, improve mileage sounds pretty good, too.

I'm in Montana, over 5000 feet elevation, and it does tend to get cold. My machinist friend has talked to a few people who have messed with the aftermarket efi's, and hasn't gotten good reports as to reliability, and has heard reports of trouble with adjusting them for our altitude.

So, what I'm wondering is:....

those of you who have had these installed for several years, how has the reliability factor been, after quite a few miles? Cold starting? Say, down around between 20 and 30 below zero? I'm likely to be towing pretty heavy loads, too, if that matters in this whol;e equation. Overall, which way do you think you'd go, if you were me?

Aaron

 

[gmbellew]

Why not just keep the factory TBI if you are going EFI?

 

[AuroraGirl]

Why not just keep the factory TBI if you are going EFI?

Factory TBI is janky and the components are old/tired and the wiring may be getting a little yikes

But this is preferable to a cheap EFI, but a quality EFI system would be worlds more reliable, interfaceable, modular etc

 

[gmbellew]

Factory TBI is janky and the components are old/tired and the wiring may be getting a little yikes

But this is preferable to a cheap EFI, but a quality EFI system would be worlds more reliable, interfaceable, modular etc

TBI sensors are cheap. The OP didn't specify the condition of his current TBI setup. But I wouldn't recommend trashing a good TBI set up for an after market EFI setup.

 

[AuroraGirl]

TBI sensors are cheap. The OP didn't specify the condition of his current TBI setup. But I wouldn't recommend trashing a good TBI set up for an after market EFI setup.

I would agree, I would only do the EFI if it was a insane desire for MPG and money to burn, the total system was just ass from wear/age/neglect and fixing it or swapping would not feel worth its own cost

Super custom application since if you like to tune and stuff you dont need to make a prom chip just need to upload new calibrations /settings

 

[AaronW]

I'm pretty sure the computer is shot in my old TBI system. My thought was, if I'm going to keep an electronic fuel system, then maybe I should upgrade, and if not, then maybe I should just get the benefit of going completely computer free. I guess while I'm at it, here was one of the fuel problems I was having: I'd get up to about 50-55 mph, and suddenly I'd lose all my power, my service engine light would come on, and I could only do 30 mph or so. I was also having trouble blowing fuses on every time I switched to one of my fuel tanks too, all of which added up to some more reasons I thought it might be a good idea to revamp my fuel system.

Aaron

 

[gmbellew]

sounds like a wiring issue with the fuel tanks. or maybe a bad switch.

if the check engine light was thrown, you can pull codes to diagnose. anything is just a guess without that info.

the "computer" will likely never wear out. sensors wear out and are readily replaced. wiring can get modified by POs hacking, eaten by mice, and can rub and wear through the coating causing shorts. that is harder to track down usually...

 

[WP29P4A]

Save yourself a ton of frustration, fix the electrical issues first. If the power and ground to your TBI system are not reliable, your TBI will never be dependable. We are at 5000' elevation here and my son's TBI works great here. Easy starts and warm ups in the mornings, gets great mileage. LOL (just kidding about the mileage)

I would keep the stock TBI and keep a couple spare parts that have been pre verified to work. (pre tested) in the truck so if you are miles from nowhere you can plug in a new module and be back on the road in minutes.

If you have a fat wallet and no budget I would go for a high quality FI system. I think between the 3 systems, carb, FI and TBI. If you were to break down somewhere I think your best chances of fixing one of them in the middle of nowhere would be with the TBI.

 

[AuroraGirl]

Save yourself a ton of frustration, fix the electrical issues first. If the power and ground to your TBI system are not reliable, your TBI will never be dependable. We are at 5000' elevation here and my son's TBI works great here. Easy starts and warm ups in the mornings, gets great mileage. LOL (just kidding about the mileage)

I would keep the stock TBI and keep a couple spare parts that have been pre verified to work. (pre tested) in the truck so if you are miles from nowhere you can plug in a new module and be back on the road in minutes.

If you have a fat wallet and no budget I would go for a high quality FI system. I think between the 3 systems, carb, FI and TBI. If you were to break down somewhere I think your best chances of fixing one of them in the middle of nowhere would be with the TBI.

this is true. the ground to the intake/thermostat is a terrible factory decision for the ECM ground and the grounds to the cab frame battery etc all need to be good. esp the side posts, peel the rubber back and you often find a lot of corrosion

The threads on a battery can be cleared with a tap and that can help if its become nasty

 

[Ricko1966]

Okay reliability being able to fix it 100 miles from home ice fishing. Your fuel pump wipes the lobe off the cam on your carbed application or even just the fuel pump dies.Unless you have a pump with you ,you are just as stuck.Okay you go aftermarket EFI instead of TBI,now you are really stuck because your local parts store won't have any of the pieces you need. I like qjets but TBI is way better abd seriously TBI is just about as reliable as anything you could buy ir put on that truck.

 

[Frankenchevy]

Okay reliability being able to fix it 100 miles from home ice fishing. Your fuel pump wipes the lobe off the cam on your carbed application or even just the fuel pump dies.Unless you have a pump with you ,you are just as stuck.Okay you go aftermarket EFI instead of TBI,now you are really stuck because your local parts store won't have any of the pieces you need. I like qjets but TBI is way better abd seriously TBI is just about as reliable as anything you could buy ir put on that truck.

I haven’t had any issues with my Eddy ProFlo4, but did quite a lot of research on the Holley Sniper when I had it. Fortunately the Holley guys thought of your scenario and used all off the shelf injectors and sensors; meaning, from regular GM vehicles from recent times. You’d probably be more likely to find parts for a sniper at your local Napa or O’rielly’s than for a q-jet.

Not arguing the reliability aspect, just that the parts are pretty dang easy to come by in a pinch.

 

[AuroraGirl]

I haven’t had any issues with my Eddy ProFlo4, but did quite a lot of research on the Holley Sniper when I had it. Fortunately the Holley guys thought of your scenario and used all off the shelf injectors and sensors; meaning, from regular GM vehicles from recent times. You’d probably be more likely to find parts for a sniper at your local Napa or O’rielly’s than for a q-jet.

Not arguing the reliability aspect, just that the parts are pretty dang easy to come by in a pinch.

At least if you are asking for the right applications for the new parts. I suspect a 9.50 an hour high schooler may not know much about a Qjet let alone the stores computer system lol!

 

[Frankenchevy]

At least if you are asking for the right applications for the new parts. I suspect a 9.50 an hour high schooler may not know much about a Qjet let alone the stores computer system lol!

Yep. There’s a post in the Holley forum with every part number that I printed out and put in the glovebox back then.

 

[AuroraGirl]

Yep. There’s a post in the Holley forum with every part number that I printed out and put in the glovebox back then.

Thats the way to do it.
Yet, there will be some workers at those autozones and oreillies who "need to know whats its for"
bless their souls

Fortunately I know for a fact that those places let you search a part number they just have to be willing to take your word on it (as if trying would break something?)

 

[75gmck25]

One slightly different method if you know the exact parts number. I have found it useful to google search for the parts number and see if you get a hit from a local parts store (Autozone, NAPA, etc.). Then print out the page and bring it in to have them find the part. In many cases the web site even has a search option to see which store actually has it in stock.