Holley Sniper EFI for BBD Carbs

tower210

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
Olathe
State
KS
#61
How large is the surge tank? This seems kinda like adding another point to have issues....
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#63
How large is the surge tank? This seems kinda like adding another point to have issues....
It is roughly 4” dia x 8.5“ tall. Holds just under 1/2 gallon. +/-

I don’t view it as adding another failure point so much as not eliminating one. For fuel injection you must have a high pressure electric pump. So, adding a surge tank with an electric pump is the same as adding an in-tank pump. Only difference is with the in-tank pump the stock mechanical pump is eliminated.

Changing out the mechanical pump is simple and they are cheap, so I‘m not too worried.

Next difference is external pump vs internal. I could have used an external pump, I did buy the Holley master install kit and it uses an external pump. But I decided to use a submerged pump since I personally think they are more reliable. I did not want to drop the tank and modify it, so the surge tank was a good alternative. As a side benefit, all the wiring I need to do is under hood, and I don’t need to run 15’ of power to a rear pump.

If I do have an electric pump issue, it is under the hood and can be swapped rather quickly without dealing with 20 gallons of gas.

Plus, I have not seen this method used on a Jeep and I want to see if this is a good alternative to the in-tank pump.

Being in Houston heat, I don’t want to deal with potential vapor lock issues with the external pump.
 
Last edited:

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#64
Working on my vacuum hose routing. This late ‘83 model has the emissions system you would find on an ‘82 with an air pump etc...

08262418-FF22-4A77-BBB5-BDD4049ABEE8.jpeg

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8839FF2F-282E-43D8-8A73-0E749196DA91.jpeg

I am NOT sticking with this system, as the O2 sensor would be very inaccurate with the air injection.
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#65
Here is a similar vacuum diagram from the ‘82 service manual. (Note that this is normal cooling and the under hood decal is for heavy duty cooling. I am routing more like the normal cooling as I used the Heavy Duty Cooling temperature switch for the EFI temperature sensor. Also, I want less vacuum hoses.)

2B83A7FE-9030-4AFD-AA48-668D913E8F97.jpeg

And, this is how I plan to route the vacuum lines.

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Some of the major changes are:

Full manifold vacuum to the distributor advance

Cold manifold vacuum to the heat stove trap door (this might be a mistake, but not a huge one in Texas)

Interesting that the heavy duty cooling shown on the Jeep is actually simpler than the version in the factory service manual.

AFCB0ECD-EAD5-48DF-93F9-188D47E068E3.jpeg
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#66
Getting closer, done with what feels like a mile of vacuum hoses. Still need the fresh air intake hose to the PCV system. I thought it was 3/8”, but it is much larger. Looks like 5/8” almost. I need hose in that size and a 3/8 to 5/8 reducer to finish it off. Then on to wiring.

1C002B02-281C-4C5B-8C15-BB92592B0F77.jpeg

I also need to find a plug for the sol-vac switch hole in the air cleaner. This Jeep was missing that switch when I got it. I might have one from my scrap engine though.
 

retiredFF42

New member
CJ-8.com Member
City
Springhill
State
FL
#67
I have the Holley Sniper BBD efi set up in my CJ8. I am very happy with it and have done a little trail running with it and have had zero issues. In fact my only complaint was the inline fuel pump set up that came with my kit. It was VERY loud, I tried several fixes with no resolution and finally installed an in tank pump which solved the problem. your install looks very nice!
 

Belizeit

CJ-8 Member
CJ-8.com Member
City
River Ridge
State
La
#68
I have the Holley Sniper BBD efi set up in my CJ8. I am very happy with it and have done a little trail running with it and have had zero issues. In fact my only complaint was the inline fuel pump set up that came with my kit. It was VERY loud, I tried several fixes with no resolution and finally installed an in tank pump which solved the problem. your install looks very nice!
What intank pump did you use ?
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#70
One good thing about using a surge tank under the hood is the very short power feed to the pump. Most of this will be cut off.

6C75CCB0-65F3-446C-B917-CAEF0890191D.jpeg
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#71
Ran the positive (blue wire) to the fuel pump. Ran the negative to a common body ground hooked directly to battery negative (Yellow 10 ga wire).

D9B5E9B6-4EA9-43E4-AB52-04EB520AB541.jpeg
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#72
Clipped the pink wire short to connect to the carb idle solenoid power feed.

CF6AB9F2-67BB-4069-AC34-F522CB278F9D.jpeg

The bullet connector was not fat enough so I had to pry it open. Not thrilled with this, but it will work just fine. After looking over the Holley wiring, the pink wire is only used as a relay trigger. The Holley ECM and Fuel Pump feed are both run off this relay, so very little current is carried by the pink wire.
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#73
Next up, positive battery connection. Small red wire is direct feed to Holley relay.

EFD20FD7-D8BB-4672-82D8-D06F17AB98FC.jpeg

Then to the negative. This Jeep has a home made negative cable made from a welding lead. Runs from the battery to a bolt on the starter. I am not thrilled with the bolt on battery terminal, so I bought a crimp on terminal.

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But the crimp on terminal is too small. I have a 1/0 crimp terminal on order.
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#76
Ran through the initial setup, and hit finish:

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No SD card in the display. OK, I got an SD card and inserted it, nope, it does not have the required calibrations. Grrrrrrr.

Apparently this should have been shipped from the factory with a Holley supplied SD card with the files already loaded on it. I did not have this card. Fortunately Holley has these files on their support page and after loading them on the SD card, I was able to finish the setup.
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#77
Next step is verify all signals and throttle range. Signals look good, but throttle range, nope. Getting 0 - 50% (occasionally 60%).

So I borrow Bigwalton’s solution. I grabbed a piece of phenolic toilet portion left over from a job and build a gas pedal shim.

5F704C15-E836-4557-9E0A-13A79E9CD6A2.jpeg
This gets me to 85% range. To get more I will need to replace an egr bolt with a button head or similar as the throttle rod is fouling the bolt.
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#78
Now time for initial startup, (after dry starting to let the mechanical pump fill the surge tank) crank the engine and STALL! No coil signal.

Time to diagnose. I have ground at the green coil wire, but when cranking the ground is not being interrupted while cranking. This means I have an ignition module or distributor or wiring between issue. So, I will now be troubleshooting the ignition before I can get it to run.

I am also hearing what sound like an electrical short from the throttle body when it is triggering the injectors for the prime start function. Very odd sound.
 

Belizeit

CJ-8 Member
CJ-8.com Member
City
River Ridge
State
La
#79
I've been wondering where I would mount my display also. Not sure I want it just above the defrost though. Good luck on the start up. Looking forward to hearing all about that.
 

ag4ever

Average Nut
LIFETIME
CJ-8.com Member
City
Richmond
State
TX
#80
I figured glass is the best place for now. I’ll probably move it to the top of the windshield as it is tilted back pretty good as it is.
 
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