78 NYB Holley Sniper install.. the end of my lean burn fun

[73 T&C]

Last December 30th marked the fifth year of my NYB adventure.

Looking back on my original thread, I’m humbled by all the help received from fellow members. I also realized, how much we’ve done and learned in that time.

So… I’ve been mentioning, on my other main thread, that I would replace the original working Lean Burn ignition with its logical “next step” of development had Chrysler taken it to fuel injection….Namely: the Holley Sniper. There are other systems out there and I did look at them but settled on the Holley system having seen it on this site (and others) being installed to excellent effect.

Specifically, I chose the Holley Sniper 550-511D kit which included an in-tank pump to provide the pressurized fuel needed.

Having restored a 76 and then a 77 Cadillac Seville, I knew a thing or two about antique and simple fuel injection systems. Both these cars had external pumps which then fed pressurized fuel (similar to Mercedes). Both systems exposed the pumps to problems with weathering exposure, (and damage) which I did not want to do. I figured we could set up the in-tank pump so I could access it through the trunk if I worked it carefully.

So that’s where we will start. Let the fun begin!

Partial kit contents

El pumpo

Great instructions that even a moron like me can understand with a few re-readings

Tank out…. No big deal. Hardest part was dumping 20 plus gallons of premium. I put most of it in my wagon and gave the guys in the shop the rest with a “Who wants it “ offer…. It didn’t last.

Where we decided to put the pump. Commando’s suggestion. Thanks.

The kit…. Black because the Thermoquad was mostly black…. Not that anyone will see it under the air cleaner.

Well,at least, I found out why the sender was getting wonky… gloat was filled with gas. New sender with float on the way. No need to have to go through this again any time soon…. I hope!

Will need to fabricate a cover over the pump as it will protrude into the trunk. Fuel line will be routed to the front (I think, still working that out in my head) to then intercept the original hard fuel line to the engine bay

First test fit on the engine… linkage will need some McGivering to get it to work but nothing too difficult to solve. At least it’s on the correct side!

 

[commando1]

Is that fuel pump intruding into the trunk going to interfere with the spare tire?

 

[73 T&C]

Is that fuel pump intruding into the trunk going to interfere with the spare tire?

It shouldn’t. Tire should span over it. It will get its own sheet metal cover.

 

[Trace 300 Hurst]

Just a thought, and I'm sure you already know this: When you "intercept" the original hard line, you still have original rubber line here and there that's not intended for 58.5 psi. I figger you'll be replacing any OEM rubber with fuel injection hose, etc.

 

[Trace 300 Hurst]

Cool project, looking forward to following your progress.

 

[Justin Plant]

Been wanting to do this with my car, please keep it coming.....

 

[twostick]

Make sure you keep any of the harness going to the Throttle Body away from the ignition wires, the distributor, coil, alterator and their associated wiring. These components are terribly noisy electronically speaking and will transmit all manner of crap to the ECM which will act on it, badly I might add.

A buddy of mine did a super sanitary install on a 68 Roadrunner. He hid all the wiring inside the factory harness. Beautiful job. Unless you took the air filter off, you would never know it had EFI except it would barely run.

It was picking up noise from the alternator cable and the ECM was reading it as a 2500 RPM wide tach signal. He moved all the EFI stuff away from the factory components and it runs like a new Hemi now.

Kevin

 

[fury fan]

Hopefully you chose a model that has ignition timing control - that is where most of your drivability and spunk will come from.
I have an MSD timing controller that allows me to add a bunch of timing when the engine is cold and it makes a huge difference in drivability before it's warmed up.
And what I have is setup as an on/off thing - so variable timing changes, based on a variety of ECU inputs, is truly a benefit.

Another big mistake folks make is NOT connecting the ECU power leads directly to the battery. Connecting them other places can cause issues, I've seen that in so many tech/Q&A questions over the years.

 

[fury fan]

Also, Holley makes in-tank 'musclecar' pump items, maybe one could retrofit to your tank?
Mioght be easier to modify one of those than to cut on your tank and trunk floor?

Holley Sniper EFI 12-314 Holley EFI Fuel Tank Modules - 255 LPH - Mopar B-Body

 

[CBODY67]

Another big mistake folks make is NOT connecting the ECU power leads directly to the battery. Connecting them other places can cause issues, I've seen that in so many tech/Q&A questions over the years.

Might that be remedied by using a dual-terminal battery, with the normal wiring going to the "top posts" and the EFI wiring going to the "side posts"?

Just curious,
CBODY67

 

[twostick]

Hopefully you chose a model that has ignition timing control - that is where most of your drivability and spunk will come from.
I have an MSD timing controller that allows me to add a bunch of timing when the engine is cold and it makes a huge difference in drivability before it's warmed up.
And what I have is setup as an on/off thing - so variable timing changes, based on a variety of ECU inputs, is truly a benefit.

Another big mistake folks make is NOT connecting the ECU power leads directly to the battery. Connecting them other places can cause issues, I've seen that in so many tech/Q&A questions over the years.

The dreaded ground differential.

Kevin

 

[3175375]

Make sure you keep any of the harness going to the Throttle Body away from the ignition wires, the distributor, coil, alterator and their associated wiring. These components are terribly noisy electronically speaking and will transmit all manner of crap to the ECM which will act on it, badly I might add.

A buddy of mine did a super sanitary install on a 68 Roadrunner. He hid all the wiring inside the factory harness. Beautiful job. Unless you took the air filter off, you would never know it had EFI except it would barely run.

It was picking up noise from the alternator cable and the ECM was reading it as a 2500 RPM wide tach signal. He moved all the EFI stuff away from the factory components and it runs like a new Hemi now.

Kevin

In situations where being near a noisy electrical bundle, crossing the bundles (ego and noisy) at right angles helps tremendously.

 

[CBODY67]

That recommendation sounds just like looming spark plug wires which can fire near each other. Cross them at right angles to prevent induction firing and maintain a certain distance between where they might be parallel to each other. But in the case of the EFI ECU, might be best to use electrical shielding fabric and ensure the grounds are really good?

 

[70NEWYORKER]

Make sure you keep any of the harness going to the Throttle Body away from the ignition wires, the distributor, coil, alterator and their associated wiring. These components are terribly noisy electronically speaking and will transmit all manner of crap to the ECM which will act on it, badly I might add.

A buddy of mine did a super sanitary install on a 68 Roadrunner. He hid all the wiring inside the factory harness. Beautiful job. Unless you took the air filter off, you would never know it had EFI except it would barely run.

It was picking up noise from the alternator cable and the ECM was reading it as a 2500 RPM wide tach signal. He moved all the EFI stuff away from the factory components and it runs like a new Hemi now.

Kevin

Local guy is fighting the same issues on a Firebird. I made a bit of a smartass suggestion that he should keep some tin foil handy. He reached in the back seat and pulled out a roll of Reynolds Wrap. He's been wrapping everything he can think of to get it to run better.

 

[twostick]

Local guy is fighting the same issues on a Firebird. I made a bit of a smartass suggestion that he should keep some tin foil handy. He reached in the back seat and pulled out a roll of Reynolds Wrap. He's been wrapping everything he can think of to get it to run better.

If he's using the magnetic pickup in the distributor for a tach signal, I would recommend running a shielded coaxial cable from as close to the pickup as you can make the splice. There isn't an electronically noisier place on the planet short of a bolt of lightning than inside a distributor cap.

I had a Holley Commander 950 that would not behave until I did that.

Kevin

 

[73 T&C]

Hopefully you chose a model that has ignition timing control - that is where most of your drivability and spunk will come from.
I have an MSD timing controller that allows me to add a bunch of timing when the engine is cold and it makes a huge difference in drivability before it's warmed up.
And what I have is setup as an on/off thing - so variable timing changes, based on a variety of ECU inputs, is truly a benefit.

Another big mistake folks make is NOT connecting the ECU power leads directly to the battery. Connecting them other places can cause issues, I've seen that in so many tech/Q&A questions over the years.

I was considering connecting to the starter relay batt connection and at the block where the ground cable is mounted. I figured these are both connected directly to the
Battery with heavy enough wire to be almost the same as a direct connection to the battery. Are you telling me it isn’t and that it will be a problem?

 

[73 T&C]

Might that be remedied by using a dual-terminal battery, with the normal wiring going to the "top posts" and the EFI wiring going to the "side posts"?

Just curious,
CBODY67

That’s what they did in the video. I may just do that. Hey…. What’s another $150 bucks?

 

[73 T&C]

Test fit of pump through trunk floor.

You can see how the spare should span over it.

Going to fab a simple cover plate to go over the pump and lines going out of the pump. Will either cut the hole larger to allow for the lines or run the lines separately through the trunk floor (toward the axle hump). I figure I can put a foam seal on the access cover for the pump to seal the opening with the lines.

The goal is to have it function and look like it was OEM.

Here’s a sketch of what I’m thinking for the cover.

 

[73 T&C]

Also, Holley makes in-tank 'musclecar' pump items, maybe one could retrofit to your tank?
Mioght be easier to modify one of those than to cut on your tank and trunk floor?

Holley Sniper EFI 12-314 Holley EFI Fuel Tank Modules - 255 LPH - Mopar B-Body

Too late…. Trunk floor cut.

It seems Holley agrees with my locating the pump in the tank….

 

[Knebel]

The Holley is similar to the fitech I have. Let me give you some tips to save some grief:

-Keep ANY signal wires far far far away from the ign coil, its wires and any high current noisy stuff.
- Ferrite magnets will be your friend on most positive electrical wires surrounding the TB, you can even put a bigone on the alternator output. Look into that.
-strip a seperate ground from a carb stud to the battery.
- buy braided shielding, put your tach signal and distributor wires in. Solder a small wire on one end with an round terminal and attach to ground!

If you need tuning tips or you have issues you dont know how to continue, I can help. I've been playing with my efi for 5+ years and tuned out a lot of issues! Lucky for you the holley is easier to tune because terminology is rather similar to a carb! But you will love this just changing numbers on the fly instead of Jets!!