A bit late to start this thread but what the hell.
So I bought the Holley Sniper back in August but decided I'd make it a winter project so I'm just getting around to starting the install.
The thing cost about $1200. But of course, as with everything else, that is only the starting point. So in talking with some other guys on EFI forums I was told I would need to update my charging system from the old 37amp alternator and remote voltage regulator. If you've read my other post, you know that I've now installed a 94 amp unit with internal regulator and upgraded my wiring a bit. Yesterday I got under and pulled my old Holley elect fuel pump and the system I had installed awhile back to counteract the fuel starvation issues I've had at the racetrack. Dropped the gas tank and swapped the sending unit with the one I modified to connect to the new external fuel pump. Fabbed the mount for the pump. Now I'm ready to stuff it back up in the car. Maybe I'll get it back in tomorrow and get the hoses put on. Once I get it back in I'll wire it up to a relay as well. I'll update this as I go along.

I’m sure you’ve seen the EFI gas tanks they sell now with internal fuel pumps. That looks like the way to go as long as you’re shelling out the bucks

I wanted to buy a complete kit so I went with the external pump. Everybody says the Tanks with the Walbro pump installed is the way to go but it meant ordering that separately and more expense so this the way I went and now I'm stuck with it( at least until the pump gives up). Should be fine. I've heard from guys that have been running this way for years without issue.

More of a concern for me is if the system will be able to adjust to my driving conditions. Different parameters can be tuned in but with the cheaper systems there is only so much that can be done.

I'm doing an efi swap too.. watching this thread like a hawk.. lol

Ok, had a fairly frustrating day in the garage yesterday. I put the gas tank back in the car with the sending unit that I modified for the new pump setup. The EFI is setup to use 3/8" lines for the feed and the return lines. I had just installed a stock 5/16" return line with the last motor install so I figured that should be adequate. The return only carries 3psi, not sure what kind of volume, but it's free flowing so I'm hoping it doesn't cause a restriction. Just have to adapt the 3/8" hose to 5/16" hard line. So you try to explain to the girl at twilight zone that you need fuel injection hose, not just regular old fuel hose ( what kind of car is it for? Is it a 2 or 4 door?...UGH!). Anyways get the tank in and start to hook up the hoses and that's when I realize the replacement sending unit I used has a 1/4" return line installed on it. WTF?? Tank comes back out. Now I have to modify my original sending unit that I added the 5/16 hard line into. Of course it's all stainless so I can't get solder to stick. Meanwhile some other [censored] gets broke while I'm dicking around with it. CRAP! Two trips to the hardware store. I finally get it back together install it in the tank, back in the car. Get my hose run and everything clamped. Whew! Onward ho. Next up, pull the intake to notch the divider and reinstall. Then I think it will be time to drop the throttle body on and run the fuel lines to it. Stay tuned. (Pic is the 5/16 to 3/8 barbed hose adapter)

my efi went pretty smooth.. I'm waiting on some hall effect tach chip.. they say the tach signal is unreliable from the HEI... I also went with a edebrock sump kit.. be interesting to see how that works...

So got my fuel pump reinstalled after the day of carnage. Decided to install a relay to run it off because the same power feed covers all the injectors on the same circuit and I didn't want to overtax it.
Pulled the RPM intake today to notch the divider. Was way easier than port matching a whole new single plane. Got the EFI mounted. Have to fab an extension for the throttle linkage so I can use my original cable.
Next up wiring and plumbing...

Looks like you're getting things done despite the snags. What was the idea behind notching the intake divider? Something specific to the EFI or same reason as cutting it for carb use? Man that RPM sure looks tall when you look at it upside down.
Just be thankful you didn't have to catch a ferry boat at 7:30, go see the girl in the twilight zone, try to explain to her what you want is not manufacturer, model, or year specific, get home at 4pm just to find what's in the box is not what's written on the outside of the box. Used to be parts guys where car guys. Can't find a gear head behind the counter at most stores now.

Holley, in their infinite wisdom, says a single plane works best with the EFI. Some say a dual plane works fine. Apparently there is a sensor that reads pressure inside the plenum. With the divider in the dual plane you're only reading pressure on one side so if you open a window in between it allows the pressure to be read on both sides( so goes the theory). Makes sense I guess. This was much easier than going to all the trouble of getting a new intake and doing all the port matching again. Besides I like the hp/rpm range it has with this intake. A single plane would probably change that.

I feel for you Al. It's bad enough when it happens to me and it only takes me a few minutes to go get something. Sometimes I just buy two of whatever because I figure one is probably broken( or going to break)/bad/wrong. At least then you have a 50/50 shot. You can always return it next time.

Ok, so I've spent the last couple of days running wires and soldering connections( I'm really slow). Think I've got just about everything hooked up how it's supposed to be. You know those YouTube videos that say, "oh it only take a day to install one of these", yeah, I'd like to see that. Maybe if you had a full electrical supply store on one side and an auto parts store on the other...still. Anyway still have to drill one hole and grommet to run the main power from the battery. Then I have to make sure the cable for the 02 sensor is long enough to reach( iffy ). I may have to buy an extension cable if it doesn't. Once that's done the elect portion of the install will be done. Then I still have to replace the rubber connector hoses between the hard lines at the cross member under the motor, then from the fuel stock fuel pump location up to the unit. Getting there. This would be so much easier with a lift!

Wouldn't a lift be great? Every time I go to Princess Auto and pass by one my credit card starts to vibrate. My garage ceiling is not high enough, thank God, the credit card would somehow win and I'd buy a lift I can't afford.

When you put the SI alternator in, did you have to put a diode in the alternator power on wire circuit? I seem to remember reading one would be needed with an MSD ignition box to prevent run-on. I put one in mine as the worn out old ignition switch bled voltage out the ignition wire even when in the off position. Not enough to keep the ignition on before I installed the relays but enough to hold the relay on and of course that supplied enough to cause the run on. I don't have an ignition box.

I have a 4 post lift.. my walls are only 8 foot.. I made that section of the garage cathedral and I can walk under without ducking!!!

I agree about the 1 day install... I ran into other issues too and ended up replacing the heater box and dash speaker. Did u have to replace the chip in the distributor for the tach signal??

Al, I didn't install a diode. After the upgrade of the alt I fired the car up to make sure i didn't screw anything up and all seemed to be good. No alt light on in the dash and it shut off like normal. There's already some sort of diode or some little doohickey in one of the wires leading to the old voltage reg. Maybe the instructions say you need one if ones not already there.

Jman, I always used the signal for my tach from that one plug on the end of the MSD box run straight to the tach. With the Holley wiring they utilize that connection for a signal to the ECU and a dark brown wire from the ECU to signal the tach( supposed to be a square wave signal). I'm hoping it works like it used to. I'm still running my HEI with no timing control till I get this thing up and running. Once I get everything sorted out I'll attempt to switch over to the other Dist.

That's a good idea, removing the flat ceiling and making parallel cord trusses for more height and still have two feet of insulation. Alas, my garage is low slope and the wall dividing it and the back room is non-load bearing.

Uh oh! We got trouble. I knew this thing wouldn't go smoothly. Got everything buttoned up last night and ran through all the setup BS. Everything looked good till I tried to fire it up. No spark. Fuel system is working the way it should but I'm not getting any spark. The MSD controls the spark so something is not connected right but for the life of me I can't see it. RRRRRRR! I hate electronic things.

I'm not looking forward to the programming part.. just incase anyone finds this post .. the edelbrock universal sump kit for use with EFI DOES require a vent to the tank no matter what it says in the description.... lol,,, I wish I knew that up front.. I would have just replaced the tank.

Hey Robert, is there a light on the box to tell you if it's getting power? You most likely have it wired to a + and - for overall power and the wire from the ignition switch to turn it off and on. Did you end up putting a relay in to switch the box off and on? If so is that wired so it's actually giving you 12 volts switched? Seems you had this box before the efi install so the coil trigger and tach connections would all be the same? Too bad your 1300 miles away, sometimes a second set of eyes help.

I think I need a couple other sets of eyes. I'm beginning to think the coil went bad or the box or the Dist quit on me. Doesn't seem likely but I'm about to start swapping out parts till something works. It may be as simple as the EFI being configured for timing control but I don't know how to get in there and check. Very frustrating.

The tach signal was the most confusing on my set up. I had a modern dizzy and still had to replace the chip inside.

I didn't realize that I hadn't updated this thread.
So I stared at that wiring for 2days and waited for something to jump out at me and say here I am. No such luck so on the third day I decided I'm just going to start swapping things out until something good happens. I started with a spare MSD box I had on the shelf...nothing. Then I pulled an old crusty coil out of my swap meet box. I couldn't for the life of me find a coil wire so I pulled the end off an old plug wire and stuffed it in the top of the coil. Jumped in and turned the key. VIOLA!!! We got fire. I just don't understand how a coil could go bad just sitting there. Friggin weird. Ordered a new one from Summit and it seems to be all good. Still haven't had a chance to get it out of the garage yet but it seems to run good. We shall see.

Got a clear day today with not much planned so I was able to get the car out for awhile. Started it and let it idle in the garage for half an hour or so till it finally got to 160 degrees and the ECU started its " learn" mode. Went down and got some gas and drove around for about another half hour or so. Did some neighborhood driving mostly under 30mph. Then pulled a few hills and pushed it a bit. Then made a couple hard first and second gear pulls. I've heard it takes a few trips for the EFI to get adjusted but I'm very happy with the way it's running. No cold start issues, which nice. It seems to have a bit more juice than it had with my quadrajet too so that is unexpected. Hard to imagine what it would be like if it ever did hook up. Friggin crazy! I'll give it some time to settle in before I swap distributors out and wire it up for timing control. So far I'm happy.

No real new news to report about the system. Just wanted to keep this thread current. I did get the car out last weekend for some running errands. Still seems to be running good. It has a slight hiccup I find when I first let out the clutch. If I'm not real careful there seems to be a slight flat spot. There are some fuel enrichment adjustments that can be made in different areas of the fuel curve. I may try to tune that out. I also need to dial in a lower idle setting. I think I had entered 850rpm originally. They say when the learn mode slows down its near the end of its self adjusting and to go into the ECU and manually reduce the " learn" percentage so it will stop adjusting the fuel. At that point I can install my new distributor and set up timing control but first I have to get the lead for the handheld display run through the firewall and hooked back up so I can see what it's doing on the fly. It's got a big plug on the end of the cable so I may have to make a new hole to do that. I'm not thrilled about that. More coming...

Bought another intake to replace the RPM I've been running. The throttle body of the Sniper is a bit taller than my jet and I was at the very limit on height before. Swapped out the old RPM for a Hurricane today. Now I have tons of clearance. I may go to a base without as much drop. I have about an inch and a half to play with now. It raining like hell here so I'm not sure when I'll get it out for a spin. It'll be interesting to see what kind of difference there is going from a dual plane to a single.

Do you have an inline filter between the tank and pump? How about between the pump and the EFI? Any pics of where you installed it/them?

I put mine on top of the water pump.

Great to see some EFI installs here. I did mine a little over 10 years ago and haven't had an issue.

I have one pre-filter installed between the sending unit and the fuel pump. The second is inline right after the stock hard line ends near the original mechanical fuel pump location. Can't really see it because it's in between the motor and crossmember.

Do you have the Pump some where around the tank?
I've changed my sender/pick up to a 1/2", and am running 1/2" AN-8 line up to the engine bay. I have a pre filter but can't really see a good place to mount it.
Was thinking of mounting it on the inner fender but that would put a lot of heat into the fuel.

At the bottom of this page: http://1967firebird.atwebpages.com/efi1.php you can see that I mounted mine where the mechanical fuel pump was located.

I should have started a new thread for this but it is somewhat related.
When installing an EFI system it is common practice to install a 100 or 40 Micron filter between the tank and the electric fuel pump, depending on style of pump, and a 10 micron filter between the pump and the injectors. Don't know what type of filter they use on in-tank pumps.
I still use an engine driven pump. I have a large 100 micron filter to go between the tank and fuel pump and I use a 40 micron filter between the pump and the carburetor.
Already have the pre carb filter placed but am looking for a spot to mount the tank to pump filter. After I get the thing all back together I will crawl around under there and see where a good spot would be. Just thought if one of you guys has already done that while installing the EFI, it would save me some crawling.

When I mounted the pump I dropped the tank and removed the sending unit. I cut and bubble flared the line right at the rear edge of the top of the tank and then ran rubber FI line to the pre-filter and the another short piece of rubber into the pump. I have the pump mounted to the pass side tank strap. It was tight but it was the only way without running a bunch of rubber.

So now that the unit is up and running fairly well and the self-tune aspect has done its thing its time for the next step...timing control. I bought an HEI distributor for an 81 ( the only year that they installed FI on a true Pont motor) Pontiac FI application. It comes with no mechanical adv and no vac adv. it's a big g body HEI so I can't buy the MSD adjustable rotor for phasing so I will have to dick with things a bit to get it set up correctly. The first issue I came across last night is the magnetic trigger plug that plugs into the 5 pin module is different than the earlier years module. I didn't really want to make wire splices inside the dist but it might be the easiest way to go.

The latest...
So it seems like I've been going back and forth and watching countless hours of YouTube for months now but I guess it's only been a couple weeks. I ended up filing down the spade connectors on the wire ends to slip them into the plug on the new dist. After all is said and done I would've been better off sticking with my original dist, locking out the mech adv and buying an adjustable piece for the vac adv. I had a few issues with the instructions because my configuration didn't exactly match what everyone else had so I had to kind of guess on some of it as I went along. Sometimes wrong and I had to back up and start again. Finally got everything installed locked down and wired up right and the Sniper is now controlling my timing. I still have to download the software to my computer so I can make some fine tuning adjustments to the timing curve and the fuel delivery but it seems to be running well( in the garage anyway). I'll get her out this weekend and run around the neighborhood for awhile and let things settle in again and we'll see if it's a happy thing or not.

I did spend quite a few hours trying to use this big body HEI mostly because they said it couldn't be done and partially because I didn't want to spend the $400-$500 on the easy setup. Depending on how much you value your time at would depend on which way to go if you were to do this same sort of thing.

hows the car running??? I finally had a chance to take mine out.. there is a slight dead spot if I hit the gas hard.. if I go slow its ok... other than that seems to be running good... it did stall out a few time when I stopped on my first trip down the road.. I only went about a 1/4 mile and came back.... did yours have any issues like that that needed to be worked out?

not to hijack but just in case anyones reading this for additional info about efi installs... .. I installed the edelbrock e street 2... so far it did NOT solve the cold start issue.. its about 25 deg. this morning.. the car did not want to start without helping with the gas petal... first time turning it over it cranked several times before it even tried to fire.. I'm hoping that goes away after some driving and adjusting... the install went pretty smooth.. other than having to swap the module in the dizzy.. and I wish I had bought a new tank with efi pump and not gone with the universal sump....

Car seems to be running fine but I haven't been out of the garage since the changeover to timing control. A buddy was having cold start issues with his FITech. There are adjustments that can be made to the fuel prime that should help. My biggest complaint so far is the rpms coming down too far if I leave the clutch engaged too long when coming to a stop. I have read about some adjustments that can be done with the software that should take care of it though. My CANBUS cable comes today so I can link my laptop to the ECU. Should make it much easier to screw everything up.

I guess I don't know what I was expecting... I'm still hoping to be happy with this upgrade... it doesn't start or run like an efi car that's for sure... its hard to drive it though. we still have snow here.. lol

It probably just needs to be tuned in the right area. These things are infinitely tunable if you know how. The Sniper is the low end EFI unit and with the software and a computer you can custom tune just about every little thing you would want to. The trick is knowing what and where you want or need to make those adjustments. There is so much you can do I'm sure I'll never completely figure it out. Once I get the major kinks gone I'll probably stop messing with it. There's only one or two small issues that I'm even looking at and I think I know where to go for it so I'm not worried. I justify this whole process as I could have spent half the money on a good carburetor and the other half on a Dyno-tune session. I'm still hoping I'll get both out of this goodie. There's also the issue of RF interference that seems to effect how well things work. I'm not altogether sure how one goes about diagnosing that condition.

I do know one thing...I feel totally ripped off. I got my cable link for the laptop hook up today. 6ft of two puny wires and a usb connection on the other end for $50. Are you serious?? Just because it's from Holley. I think I'm going to start knocking off these things and make a killing. Probably $3 worth of materials in this thing.
Kind of sweet and sour though because I also got my new trunk pan for the 67 delivered today too. One year and 5 months till retirement before I'm supposed to be able to start working on it. I don't think I'll be able to hold out that long.

There are some great videos on Youtube related EFI v. Carbs and tuning. I'm kind of a Youtube junkie.

Here are a couple videos that compare EFI and Carbs.

This one shows a challenge between one guy tuning a carb and the other using EFI. My take away was that it might be worth consulting a pro when you start out with either one.
https://www.youtube.com/watch?v=ZGlRiapBEeY

This one is interesting because of the trouble they had getting the EFI to work. But in the end the EFI does shine.
https://www.youtube.com/watch?v=2sQJPZYSoUI

Enjoy.