Holley Sniper EFI with in tank pump

[GCC]

I just finished installing a Holley Sniper EFI on my 65. I have been considering doing this since rebuilding my original carb two years ago and still not being able to get things dialed in the way I wanted. I think a lot of the problems I was seeing were due to the previous owner running without the steel plate under the carb for too long, causing corrosion on the base of the carb. Anyway, another big thanks to RockinRiviDad for the post last year, which was invaluable in solving a few issues, particularly the throttle linkage. Here is a bit of a write up with some lessons learned.

 

It appeared the the tank had never been out of my car, as the original undercoating spray was all over the tank strap mounting bolts, making it impossible to back them off very far since the top is just a lag bolt in a slot. I had to carefully cut through the bolts with a die grinder using a mirror.

 

I decided to also install an in-tank pump, and as part of doing so also started with a new fuel tank from BestOfferCounts. I chose the returnless Holley Sniper module Part# 19-360.  This requires cutting a 3.25" hole in the top  of the tank, which I tried to locate in the area near the existing fuel sender hole with the least amount of indentations. 

 

I didn't realize that a vent tube runs all the way and of course the hole saw cut right through that as well.

 

I looked like I had just shortened the tube by a few inches, and the fuel pump has its own vent, so I just bent the ends out of the way and kept going. The tank depth at this point is 7.25", which is the minimum listed for this pump, but I didn't have any issues with depth. It could probably get another .25" to 0.5" shorter without problems. The instructions for cutting the hanger and pickup tube were terrible. I recommend directly measuring the pickup tube plus pump plus filter sock depth directly, then cutting the metal hanger to match. I test fit this a couple of times, starting longer than necessary, and shortening slowly until the pickup was positioned just above the bottom of the tank. 

I re-used the original fuel sender, but only for the guage. I cut off the pickup tube, and the reason I chose to cut the hole on the left side was to avoid the float position. Here is everything ready to go in.

 

Here is the finished assembly under the car and ready to strap in. I ended up having to drop it back down again to fix a couple of issues after once I got everything else together. The 1/4 NPT fitting on the pump outlet requires thread sealant or it will leak. I used RectorSeal #5 since it was available locally, although Permatex Aviation #3 was also recommended to me. You'll see some foam spacers in the photo that are needed to allow the pump to clear the underbody. These broke the grounding of the tank and the fuel guage. I had to run a direct ground from one of the fuel sender bolts to the chassis to get the fuel guage to work.

 

 

The fuel pump wire is run through the trunk and down the channel behind the rear seats and along the door channel through the firewall to the engine bay.

 

And here it is secured in place with new bolts.

 

Plumbing the fuel up to the engine bay was the next challenge. Used hard line to -6 AN adapter, and the appropriate barb to -6AN on the short length of hose from the pump to the hard line. I found the hard line to be clean and in good shape, so did not replace it.

 

I tried the same thing at the front hard line connection, but could not get the adapter to seal due to the short length of line beyond the bead. Instead I simplified and just pushed more hose down past the bead so that it could be clamped on directly. I replaced the old fuel line with the new EFI hose along the stock routing from behind the front wheel and through the frame rail and spring mount. I scraped a few knuckles on that operation because the EFI hose outer diameter is larger than original, but it can be done. I placed the new fuel filter in the stock clamp on the thermostat housing, although it is a little bigger and requires some bending of the clamp. I used the front fuel inlet on the Sniper to keep closer to stock routing, but didn't make the last connection until after flushing the fuel line into a container. If you use the inline fuel pressure guage as I did, make sure to use some thread sealant on the NPT threads there as well. I had a tiny drip that needed to be sealed up.

 

The plumbing of the vacuum lines was pretty straight forward. Note that there is a plugged port on the front of the Sniper throttle body that can be used to connect the EGR, rather than trying to tee it at the back. 

 

Next was the wiring, which honestly was simpler and smoother than I was expecting. No issues encountered there, although I still have not figured out what to do with the touchscreen inside the car. Just pulled through to the glove box for now.

 

On to the throttle linkage. Have a look at RockinRiviDad's excellent instructions for modifying the available Holley extension for the throttle rod and kickdown. Here is mine ready to go.

 

Note the temperature sensor mounted on the back of the driver side head in the above photo. This requires removing the plug with a breaker bar, and using a 1/2 NPT to 3/8 NPT adapter to mount the Sniper sensor. I left the stock temp sensor in the front of the passenger head. The surface temp read a little lower (10F) at the back location with an IR thermometer, but the actual coolant reading on the Sniper was the same as the surface temp at the thermostat.

 

Next job was mounting the O2 sensor in the exhaust. The Sniper comes with a clamp on O2 bung, but I preferred welding it in, so bought a weld in steel bung, and mounted it on the passenger side. I thought there was enough room in the location I chose, but it proved to be tough to see what I was doing in there. It might be better to mount it a little lower. Anyway, a little work with the welder and a mirror, and it's sealed up, but not pretty.

 

After that, some wiring clean up and it was ready to go. I could not re-use the stock air cleaner unfortunately, so I bought a cheap open element cleaner. Since I used the front fuel inlet, I also needed to use the Sniper drop base Part# 120-511. I may try to later modify the bottom of the stock air cleaner with that drop base so that I can use it. I will follow up with that if I go ahead with it.

 

 

I needed to update the Sniper firmware to be able to run through the startup sequence, but after that it fired right up and idled well. I made all of the recommended idle adjustments, but I'll wait for some nicer weather before I get it out for a drive. If I discover anything else through the tuning process, I'll be sure to update.

Edited January 22, 2020 by GCC
Fixed photos (see edit history)

[Craig Balzer]

GCC -- none of you photos survived your posting.

Thanx for the link to RockinRivDad's efforts

Craig

[telriv]

IF & WHEN you buy this kit DO NOT use the metal stud for the hold-down wing nut.  IF you screw it in too far it will penetrate the "Brain" of the unit.

My friend had so many problems it darn near cost him an engine all for the lack of a plastic hold-down rod that SHOULD be included in the kit.

IF you use the metal rod/stud screw it in 4 or 5 threads then use a nut to hold it in place.

Someone I know just went through this sending his unit back 3-4 times.  It was getting so frustrated he was ready to slit his throat.

[RockinRiviDad]

GCC

like Craig said, your photos are not showing up. I’d LOVE to see your photos. Sounds like u did a great job…but u know the rules…IF THERES NO PHOTOS, IT DIDNT HAPPEN 🤣

 

I am glad u were able to use some of my info. 🙏🏼

 

I will be adding a few new pix to that EFI thread in the next few days. I have to make alterations to my throttle linkage adapter chingaso. I just realized days ago that my fab’d adapter is hitting throttle body linkage & I never saw it. Live & learn

[RockinRiviDad]

11 hours ago, telriv said:

IF & WHEN you buy this kit DO NOT use the metal stud for the hold-down wing nut.  IF you screw it in too far it will penetrate the "Brain" of the unit.

Sorry to hear about your friends issue. But the “Brain” (ECU) is on the front of the throttle body behind the nameplate on these Snipers. No doubt your buddy may have penetrated “something” by screwing in the stud too far. But I don’t think it was the “brain”

 

I used a similar stud to hold my air cleaner. I couldn’t use a wing nut between the fins on my Mooneyes aluminum air cleaner. I cut my stud to fit. I must’ve gotten lucky not to penetrate whatever your buddy did when I was test fitting mine

[telriv]

What I posted is a problem that my friend encountered & was told by Holley hat the stud penetrated "Something". This was a heads up so that others don't have a future problem to head off problems & frustrations.

[GCC]

Hmm, strange that it looks fine for me. I didn't notice there was a max size on attachments. I'll try downsizing and posting in a couple of batches. Here is the first set. I tried to keep them in the same order described in the original post.

*Edit: Fixed photos in original post. Removed from here

Edited January 22, 2020 by GCC
Fixed photos (see edit history)

[GCC]

Thanks for the heads up about the air cleaner hold down. There is no rod included with the kit. I used the one that came with the new air cleaner. Cut to size and threaded in by hand until I felt resistance. Haven't experienced any issues.

[RockinRiviDad]

Not sure how to explain it. But I just found out that I need to alter my throttle linkage adapter thingy design. Mine hits the throttle body linkage not allowing full throttle. I will post pix in my EFI thread when I cross that bridge. 
 

Edit: Check yours to see that u get 100% WOT

Edited January 15, 2020 by RockinRiviDad (see edit history)

[telriv]

GCC,

   Un-thread the stud about 1-2 turns & then install a lock nut to hold it in place.  This will prevent the stud from touching whatever it is it's hitting to prevent a future problem.

   Also to try & neaten things up get 2 plastic PCV 90* fittings to install on th PCV valve & the PCV port from the front of the EFI unit.  They usually come with Chevy PCV valves. Your parts store SHOULD have them separate.  I can see by the picture that the PCV hose is appearing to collapse right in the curve where it enters the PCV valve.   The 2 90* fitings will eliminate the bends.

 

Tom T.

[RockinRiviDad]

New pix & info on new throttle bracket on my EFI thread. I hope this helps others 

[RockinRiviDad]

GCC:

Nice work 👍🏼 Your throttle bracket looks like the one I made. Mine was actually not allowing full throttle. Check my EFI for more info.

 

Don’t forget to check your throttle position sensor setting on your handheld. It’ll tell u if u got your bracket made right. 

[GCC]

On 1/21/2020 at 11:29 PM, RockinRiviDad said:

GCC:

Nice work 👍🏼 Your throttle bracket looks like the one I made. Mine was actually not allowing full throttle. Check my EFI for more info.

 

Don’t forget to check your throttle position sensor setting on your handheld. It’ll tell u if u got your bracket made right. 

Thanks for the pointer. I did have to adjust a little to allow full travel. The handheld only shows 88% at full throttle, and maxes out there even without any bracket attached. According to the documentation, anything between 85 and 100 is fine though.

I did find that the throttle rod was a little preloaded at rest since I couldn't adjust it any shorter. I ended up cutting off the top tab of the bracket and welding it back on flipped 180 and angled towards the front (I think this was what you were suggesting in your thread). The re-configuration takes care of the preload issue, and the rod travel stays a little lower and out of the way of the plug wires.

 

[J3Studio]

11 hours ago, GCC said:

The handheld only shows 88% at full throttle, and maxes out there even without any bracket attached. According to the documentation, anything between 85 and 100 is fine though.

 

Interesting.

[J3Studio]

This technologist's belief is that moving to the Holley Sniper system should improve both mileage and performance for the Riviera. However, that's just a belief. Does anybody have Riviera-specific real-world experience?

[telriv]

Not entirely true. IF ALL the components are functioning as they should there should be little or no improvement.  ONLY when the experience of the tuner/time nec. comes into play does it make a difference which makes the system attractive to most/many who don't have the experience. 

Just MHO

[J3Studio]

On 1/26/2020 at 2:53 PM, telriv said:

Not entirely true. IF ALL the components are functioning as they should there should be little or no improvement.  ONLY when the experience of the tuner/time nec. comes into play does it make a difference which makes the system attractive to most/many who don't have the experience.

 

No improvement in fuel mileage with the massively improved precision of electronic fuel injection? Is this a Buick 430/455 thing? Or is the Sniper that un-optimized, even with their claim of self-tuning?

Edited January 27, 2020 by J3Studio (see edit history)

[telriv]

That's the attraction. Instead of you doing the tuning the computer does it automatically so the average person doesn't need to know much about tuning it properly.

[RockinRiviDad]

21 hours ago, GCC said:

only shows 88% at full throttle, and maxes out there even without any bracket attached. According to the documentation, anything between 85 and 100 is fine though.

cutting off the top tab of the bracket and welding it back on flipped 180 and angled towards the front (I think this was what you were suggesting in your thread)

It’s weird that u only get 88%. Without the bracket on mine I was getting 97%. Double check all your linkage. Something might be hitting. 
 

Before I got the idea of flipping the top of the mounting tab that I described I made adjustments enough to get 86%. My kid was helping me & asked “why not try for better?” So I redid my bracket & got a 97% throttle reading. But once again, when I put the kickdown switch back on it restricts the throttle travel & I only get 92%. That’s better than the 76% I mentioned I was getting in an earlier post. I have considered an aftermarket KD switch. 

[RockinRiviDad]

10 hours ago, J3Studio said:

Does anybody have Riviera-specific real-world experience?

I definitely got more performance from my Sniper. The main reason for that is that my carb was 600cfm’s & the Sniper is 800. 
 

Better mileage? My lowridering low & slow days are long gone. If I had the discipline to drive for “better mileage” than I might be able to comment. But now I think I have a Hot Rod & can’t seem to stop doing burnouts…how’s that for “real-world experience”

[telriv]

Hows about some real world DATA???