So here's the plan ....

[Bamfster]

I've been wanting to add EFI to the Chevelle for quite a while now, and I'm getting ready to do a junk yard run. I'm planning on hitting the GM truck section and robbing them for the sensors etc, and get all of the connectors as well.

Question #1, what should I be looking for as far as injectors go? I'm at roughly 400 hp at my altitude based off ET and MPH.

Question #2, what fuel pump should I be looking at? Not J/Y .... this I feel needs to be a new component, or known, quality used pump.

My "learning" intake setup will be a Holley Contender intake manifold with a Holley 750 main body as the TB. The plan is to add my own injector bungs and fuel rails. I know a single plane will be better, but I want to keep the Victor JR and Proform 750 that is on it currently intact, until the efi is up and running. Plus it will have a pretty good resale value down the road....and ultimately, I will add a sheet metal intake when all is said and done (they look really cool!), or am I out of my mind with this idea?

I will probably approach this a little differently and take control of the ignition/timing first, and then fuel. Controller will be MSI or II, still undecided on this one. I'm pretty sure I'll go w/the relay board .... but what else do I need?

I've been thru the mega manual a few times, and I'm seeing that a project like this isn't as complicated as I first thought, but some things are still a bit greek .... and that will be the underlying reason for this, to learn.

So I'm looking for valid input with solid reasoning and experience, if you see a flaw with my plan, explain why. Is there better components/sensors/connectors I should be scrounging for? I picked what I did based on my knowledge and history of those trucks. Tell me your favorite sites, etc for finding efi parts ...

[TheSilverBuick]

Not ignoring you Dan, just waiting until I have enough time to leave a good answer! Hopefully this weekend!

[Bamfster]

No worries Randal ... I know you will have some good info and ideas .... .. as well as Scott. My target is to actually start putting parts together after the snow starts falling here.

[JeffMcKC]

http://www.ebay.com/itm/Aluminum-Fuel-Rails-and-Injector-Bungs-SET-V8-/230513659996?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item35abaf505c

This is the place I get my rails from

You can drill you own holes in the rails

The YB has efi regs on sale all the time Thats where mine cam from I have a power products on I would sell for 1/2 if you like its been on my car till this year and works fine.

[Bamfster]

Thanks Jeff .... which reg is it? I was actually looking at those but if you have one for 1/2, it'll be mine soon ...

[JeffMcKC]

It came with the EFI SBC Hurricane I know it was good to 750 HP at the flywheel

[TheSilverBuick]

Question #1, what should I be looking for as far as injectors go? I'm at roughly 400 hp at my altitude based off ET and MPH.

New injectors are probably better from a cleanliness stand point, but otherwise you'd probably want at least 32lb/hr injectors. I've ran 32lb/hr injectors in my 455 (Accel $300 for a set from Summit) for two years at 43psi fuel pressure. But I don't know what HP I was making while running them. At drag week I bumped it up to 44lb/hr injectors, still don't know what HP I'm making but I was worried I was going to start running out of injector capacity, though I think I could of bumped the pressure up to 60psi and been okay. From the junkyard, I know most the supercharged 3.8 engines had 32lb/hr injectors (or 36?). I'm sure you could find a list off the internet showing various cars/trucks and the stock injector size. I've seen one a few years ago before I bought a new set.

Question #2, what fuel pump should I be looking at? Not J/Y .... this I feel needs to be a new component, or known, quality used pump.

I'm running a stock Ford pump from a late 80's Econoline or F-250(?). They are about $100 and available at about any parts store on the shelf (even the NAPA in Ely has one on the shelf). Word of warning though, it's only a 5/16th feed, but designed for 90psi (spec's). I haven't watched what my fuel pressure does at WOT, but watching AFR's I've tuned around any defficiencies in the pump if the pressure is falling off, but I'm thinking it's been fine so far. I have a 3/8th line feeding my surge can, 5/16th feeding the pump and the injector rails, the injector rails are 3/8ths and the return line is 5/16ths. Not an ideal situation, but at my level it seems to work just fine. An A1000 and big fuel lines solves any fueling issues though

I've been wanting to add EFI to the Chevelle for quite a while now, and I'm getting ready to do a junk yard run. I'm planning on hitting the GM truck section and robbing them for the sensors etc, and get all of the connectors as well.

I picked up an intake air temp sensor (IAT) and pig tail, a coolant temp sensor (CLT) and pig tail, then 8 injector pig tails (some GM's are numbered 1-8, if you looked closely at mine the injector plugs are numbered). I'd look for/at some TBI's, and if any of the OEM ones are like the holley 2bbl TBI on my T-bird (look at 4.3 engines?) then the TPS has an arm that with a little fabbing of a bracket to bolt it to you could probably use the string method with one of those TPS sensors (and grab the pig tail!). I'm going to eventually investigate that for my Centurion.

You could probably pick up a fuel rail or two off a Chevy for either mock up purposes or a pattern to follow if you are making your own rails. I think they have 5/16th internal passage, but I'm not positive on that.

I will probably approach this a little differently and take control of the ignition/timing first, and then fuel. Controller will be MSI or II, still undecided on this one. I'm pretty sure I'll go w/the relay board .... but what else do I need?

Ignition then fuel is simple enough. What kind of distributor are you using now? If an HEI I'd ditch the module and plug the pickup coil right into the MegaSquirt, that's how I did it up until this week, when I switched to a crank trigger. I personally used an MSD 6AL box to actually run the coil and had the megasquirt send the timing signal to it (MS signal to the points pickup on the MSD box, one wire, simple), but the MS can control the coil directly if you wanted. I have an MSII preference because the idle air control valve controls, but it's just a preference, the fuel and ignition sides either or works, and both have a high/low idle control for warm up and such, the MSII can control a stepper motor for gradual rpm change. D/G may have more input on that. Because where you live, I'd recommend the MapDaddy second map sensor for real time baro correction. You can quickly drive from 85kPa atmospheric pressure to 65kPa (25% drop) which will make your car run way rich climbing the hill. Going down hill can do the same and you can go lean until you turn the car off and then back on for a new pressure reference. Now O2 sensor feedback can correct to off set those changes though, so a MapDaddy sensor is not mandatory if you are using O2 feedback to actively correct your AFR's.

I love the relay board and may get a new one soon because I've beaten mine up a bit with all the engine pulling and it being mounted on the firewall, the transmission has caught the big connector a few times bending it...but it's still working! I'd get the wiring harness from DIYautotune.com too. It comes with color coded wires that have the function written on the wiring, though it seems to be the writing has rubbed off the places I touch the wires most when hooking and unhooking the wiring up, but the color remains so it's easy to look at the sensor, see blue at the TPS so plug the blue wire into the TPS port. I may go to a quick plug if I change my relay board. Also getting a WBO2 is recommenend. The LC-1 has two outputs, one can go to the MS and the other to a gauge. It wouldn't be a bad idea to run the ignition with the MS and datalog the AFR's with the carb so you know what to shoot for when converting over to the fuel side. For disclosure, I have had one LC-1 fail on me, not the sensor, the actual unit. Luckily I had my tune pretty close and the car didn't notice and I drove it 3 months with a dead O2 reading. I haven't really ran the O2 feedback and my tune is based on baro, temperatures, load and rpm. I find it's better that way incase the O2 up and quits, but it's a preference.

I've been thru the mega manual a few times, and I'm seeing that a project like this isn't as complicated as I first thought, but some things are still a bit greek .... and that will be the underlying reason for this, to learn.

It is greek =P The best way to understand it is literally by doing, one step at a time. The MegaSquirt has so much flexibility it really is difficult to go down the wrong path. The software portion works with so many things that buying the wrong hardware is difficult. For me the hardest part was setting up the ignition portion, because the directions say "If you want a Hall/opto/points input signal do step 50 or 50a, or if you want a VR input go straight to step 51" or something like that (PLEASE DO NOT USE THAT QUOTE AS A REFERENCE! Read the manual!). Near as I can tell, just set it up the VR way and it'll work. Really you install both types then use the jumpers (as recently shown in my Buick thread) to pick the method to install. The D1 and D2 stuff is confusing too, I have both mine installed then on the backside bypassed with a piece of jumper wire (the disaster in the middle/bottom of my picture) and it seems to work fine for what I do (and likely you?). That's the most confusing part for me, and I don't think there were any other options putting it together. Just follow the directions like assembling a LEGO project If you get one pre-assembled then just use the VR input jumpers. Oh, if using the MS1, there will be additional modifications to make to control ignition and such. I'm not familar with them, but D/G is and I'm sure there is a ton of documentation out there on it as it's a very popular and easy(?) mod to use the MS1/extra software and control timing. The MS2 does it with a stock build and software (part of my reasoning to go with MSII, it was my comfort level at the time to stick with a stock build).

My "learning" intake setup will be a Holley Contender intake manifold with a Holley 750 main body as the TB. The plan is to add my own injector bungs and fuel rails. I know a single plane will be better, but I want to keep the Victor JR and Proform 750 that is on it currently intact, until the efi is up and running. Plus it will have a pretty good resale value down the road....and ultimately, I will add a sheet metal intake when all is said and done (they look really cool!), or am I out of my mind with this idea?

Seems like a good plan to me! The dual plane should be fine

[Bamfster]

Thanks for all of that Randal!

The distributor will be the Mallory Unilite that's in it now. Matt Cramer explained a way that it can and will work with what I'm doing.

After trying a lot of different injector calculators, they all point to 32 lb/hr for the 420 hp goal .... I can always upgrade later if need be. In looking at ebay, there are a ton of used/rebuilt injectors, I need a good source for researching injector sizes by application if one exists. Kinda wondering about the ford cvpi's etc .... a local yard gets a ton of those in.

As usual .... THANKS for the help!

[TheSilverBuick]

I haven't researched it in a couple years, but I found a ton of vehicles only went up to 24lb/hr injectors except for the super/turbo charged cars. Also I "think" some of the newer cars/trucks are using a smaller diameter injector than common ones used for 20+ years. Basically just be double checking the o-ring diameter's on any injectors you're looking to get to ensure it'll work and be able to swap it out easily for upgrades or repairs.

[Bamfster]

Well the dual plane intake is out .... no way to use common fuel rails with the "stepped" runners. Found a nice used Victor Jr to use at a nice price so .....

[milner351]

Bamfster - does the Vic jr already have cast in area to drill the injector bungs or will you be tig welding in some "pucks" for the injectors.

The cheap airgap knock off I have in the ranger has blank bosses for injectors and fuel rail bolts... hopefully your vic jr score has the same.

[Bamfster]

No it's just the standard Vic Jr ... no cast in bungs. I have a friend that is pretty good with a tig so I'll add my own. I toyed w/ the idea of getting one of those, but for $100, i'm getting the Edelbrock.

[milner351]

$100! Nice

[Bamfster]

So here's what I picked up at the 'yard today:

3 throttle position sensors





2 idle air control valves and a coolant temp sensor





and several different style intake air temp sensors




Now to adapt one of the tps to the throttle shaft of a holley .... thoughts and ideas are welcome.

[dieselgeek]

If you plan on running one of the Gm IACs, then it's a good idea to upgrade to the MS2 processor, as the MS1 will only drive the PWM-type Idle Controllers. Given your altitude, and Randal's groundwork on the subject of "cars that have to run good at all different altitudes" - methinks it's a good idea to go MS2 and GM-IAC.