Holley Sniper EFI conversion on a 1995 Kachina Icon 25' mcob 454/bravo 1

[Thomas K]

You can change the min learn temp or disable it.

I will look into that!

 

[Thomas K]

There's a Air Conditioning feature in the Sniper software that proactively ups the idle to compensate for the extra load of the AC compressor. It's a one wire trigger that can potentially be tied into the safety switch in your shifter to come one when you put the boat in gear (might need to be used in conjunction with a "normally on" relay). Hope that helps!

Are you talking about the no start in gear safety?

 

[Blackmagic94]

Are you talking about the no start in gear safety?

He just needs to adjust his tune mo better.

 

[DaveH]

Update. I did some other things to my boat as well. New ignition switch, new solenoids on my trim pump motor because my outdrive would not come up, even with the trailer switch. New engine control throttle shifter because my old quicksilver 3000 I really didn't like, and lubed my cables. Now I'm lake ready?
My wife and I did a shake down cruise last weekend to Lake Pleasant. She fired right up with no long crank times which was nice. When I tested the engine idle with the hose, it was very nice. Not so good on the water. My exhaust tips are below the water line when at idle. I think the added back pressure of the exhaust and actual load on the prop when in gear made for a rough idle and stalling when put into gear. My target rpm at idle was 750. I'm going to up it to 800-850 rpm. Hopefully that will fix it. Accelerating and on plane, she ran very smooth. Very responsive and she did not stumbling at any rpm. We cruised around for about 5 min. The engine temp was around 150 according to the handheld dash and so it was not into learn mode yet. I went to do a wot run to see if I could get the temp up a bit and the throttle handle went limp at 4400rpm. I thought the cable broke. After poking around a bit I found the problem.
View attachment 1115832

The plastic retainer nut broke off the cable. The left cable in the photo is the throttle with the broken nut, the right is the shift cable. The shift cable nut has stress fractures in it as well. Not good.
So I disconnected the throttle cable at the motor and operated the throttle by hand while holding the engine hatch open a bit to get my arm in there while my wife drove. Haha kinda funny.
We tried to make the most of the day but it was getting really windy so we called it. My wife did great job getting back on the trailer considering the wind ,no throttle, and stalling. I pulled the plug and a ton of water came out of the bilge. Usually it is bone dry. Turns out the shift cable bellows has a big tear in it. Pretty disappointing because I replaced the bellows last year.
I was pleased with how the sniper operated. On the motor, I'm going to swap the location of the temp sensor for the efi with the dashboard temp sensor. The dash was reading around 180 while the efi 150. I hope that will make a difference to get the sniper into learn mode. Also up my target idle speed a bit.
I ordered all new cables and a bellows kit. Today I'm pulling the outdrive to do the lower shift cable and bellows.

there is only so much "authority" the idle valve has....it can only bypass so much air. you need to find the sweet spot, with the engine warm and in neutral then open the butterfly to where it idles at target WITHOUT the idle valve. then reset the TPS to zero in the ECU. you should plug the idle valve port when doing this. once it idles at target mechanically, then reintroduce your IAC.

 

[mattyc]

there is only so much "authority" the idle valve has....it can only bypass so much air. you need to find the sweet spot, with the engine warm and in neutral then open the butterfly to where it idles at target WITHOUT the idle valve. then reset the TPS to zero in the ECU. you should plug the idle valve port when doing this. once it idles at target mechanically, then reintroduce your IAC.

2nd this

 

[Thomas K]

@DaveH Thanks. That is how I was adjusting the iac. We went for another shake down cruise yesterday. She stalled almost every time we put her into gear. Once she was in gear, she idled nice and ran wot at 4400rpm. I did mess with the cam setting. I have no idea what the cam is so I changed the settings in the handheld and what a difference. Ran like crap when I put it on mild/street cam. Stumbled and only could get a sluggish 3000rpm. Went back to the stock cam setting and that is where she likes it. I contacted Holley to see if I needed to do something different like the ac kick which @Streetmoto suggested. The Holley tech said I should not need that. Also asked about the min learn temp per @Blackmagic94. The tech did not give any info on how change it. But it would be nice to have it around 150. The tech asked me to give him some handheld info about the tps and the iac reading. The tech seems to think it is a faulty iac valve, so they are sending me a new one. Hopefully it will take care of the problem.

 

[Blackmagic94]

Go to tuning
Go to basic
Go open loop 1
Adjust temp

 

[DaveH]

@DaveH Thanks. That is how I was adjusting the iac. We went for another shake down cruise yesterday. She stalled almost every time we put her into gear. Once she was in gear, she idled nice and ran wot at 4400rpm. I did mess with the cam setting. I have no idea what the cam is so I changed the settings in the handheld and what a difference. Ran like crap when I put it on mild/street cam. Stumbled and only could get a sluggish 3000rpm. Went back to the stock cam setting and that is where she likes it. I contacted Holley to see if I needed to do something different like the ac kick which @Streetmoto suggested. The Holley tech said I should not need that. Also asked about the min learn temp per @Blackmagic94. The tech did not give any info on how change it. But it would be nice to have it around 150. The tech asked me to give him some handheld info about the tps and the iac reading. The tech seems to think it is a faulty iac valve, so they are sending me a new one. Hopefully it will take care of the problem.

before just assuming the IAC is faulty...its super easy to verify. pull it off the throttle body. find a rubber plug or equivalent to block the passage so air can not bypass the throttle.

fire it up and you can watch the IAC pintle physically move. by allowing air to leak past your plug, idle RPM will increase and you should see the pintle extend trying to choke off the air. if you can completely seal the passage, idle will be low and the pintle will retract trying to allow more air to increase RPM.

if its not moving, then either the IAC is bad or there is a problem with the wiring to it.

 

[Thomas K]

Installed the new IAC valve. No improvement. Moved the fuel pump to a lower location per @Blackmagic94 suggestion. No improvement. It seemed that she was starving for fuel. I called Holley again to trouble shoot and the tech said I probably toasted my fuel pump. I can't recommend them enough, super helpful, and after all that they comped me a replacement pump. Installed the new pump in the lower location. Immediately it started acting just like the old one. Starving for fuel. I Checked my tank pickups. One had a leaf in it. Checked the pre fuel filter. It looked good, but cleaned it out anyway. I thought maybe it was the fuel pressure regulator at the sniper unit or the post fuel filter. Pulled the fuel hose at the unit to check the flow and it was just a dribble. Pulled the post pump filter and it looked a little dirty, but not super bad. I had new one on hand so I just replaced it. Fuel flows like a garden hose now! My guess is that the post pump filter was restricting the flow so much that the unit was not operating properly and the restricted flow was causing the fuel pump to overheat, creating a vapor lock at the pump. I got it running good on the hose and then took it to a local "lake" to test with exhaust in the water and a load on the prop. I just left the boat strapped to the trailer and tested shifting. Still was stalling at every shift. I adjusted the IAC to 0%, 20%, 50%. No improvement. Hmmm. Watching the handheld when shifting, the air/fuel ratio would jump to 15-20ish and stall. The sniper came preprogrammed with a target idle air/fuel ratio of 13.4. I changed it to 12.5. She shifted without stalling! I dropped it a little more to 12.0. Even better. Now she is maintaining an idle of 750rpm and shifting with no sputter or drop in rpm. I still need to do a real lake test, but it seems that she is good to go now.

 

[Blackmagic94]

That’s why to rich for idle




Non boosted engine


Full throttle 12.5:1 afr

Cruise 14.0, ideal is Stoichiometric at 14.7:1 but you can adjust richer to get a smoother drive but the leaner you go the more fuel effficent

Idle

Depends on camshaft profile
13-14ish


Going to rich can wash the piston rings and wear them out.

 

[Thomas K]

I still have not had a successful day on the water yet. We had a huge rain storm 2 weeks ago. 1/2in of rain in 30 mins. Our boat was uncovered and it got soaked. We were supposed to go to the lake a few days later. I tried starting it before we left just to check everything and it would not run.
Water in my fuel.
I think what happened is the vent holes in my gas caps started sucking the pooled water around them into the tanks as they cooled off from the rain. Uhhhhg.
I hand pumped each tank until I saw clear gas. Installed a water/fuel separator, used Heet in both tanks, flushed my fuel lines.
She fired right up.
There was over 1 gal of water out of both tanks.
Planning on taking her out Wednesday. Will update.

 

[bonesfab]

The area in the map above the idle spot needs to have some fuel added to it. That's why it is stalling out. Get the usb cable and plug a lap top into it. Much easier than the hand helds. Snipers are very hit and miss.

 

[guest hs]

Let me know when your ready to take that crap off and put a carburetor back on it

 

[Thomas K]

My trips last week went great. I had some adjustments to make to the idle screw but after that she is running great.


Here is a question for you guys. I was watching the rpm's on the sniper handheld vs my dash gauge. At WOT the dash gauge reads 4400rpm but the handheld was around 3500-3600. AT cruise the dash was 3000 rpm and the handheld was around 2300-2500.
Which one do you think is more accurate?

 

[mash on it]

I'm just taking a wild ass guess, is the hand-held able to measure rpm for a V6? Your numbers coincide with a 6 cyl tach numbers.
4400 x .75= 3300.
3000 x .75=. 2250.

Something is off. Possibly your dash tach is set to V6?

Dan'l

 

[mattyc]

It would seem the dash tach is more accurate, BUT, if so, 4400 at wot isnt right, which would indicate a lack of power or wrong prop selection. What rpm did you achieve prior to the sniper install?

Where does the sniper obtain rpm signal? From the distributor?

Maybe obtain a timing light with an rpm display to verify?

 

[DaveH]

the handheld is correct.

your tach output or tach itself is where the issue is with the RPM mismatch.

quit looking at the wide band. It is HIGHLY inaccurate at idle. sorry but you have to use your brain, turn off all the stupid target and self learn BS and actually tune it.

 

[Thomas K]

It would seem the dash tach is more accurate, BUT, if so, 4400 at wot isnt right, which would indicate a lack of power or wrong prop selection. What rpm did you achieve prior to the sniper install?

Where does the sniper obtain rpm signal? From the distributor?

Maybe obtain a timing light with an rpm display to verify?

It is wired to the distributor. Before I was only getting 4000 at wot, that was with a 25p four blade. I have a 23p four blade on it now.
I thought the wot throttle for a 1995 454 is 4400-4600rpm

 

[Blackmagic94]

The Holley is accurate on rpm. You tach is not.

 

[renodaytona]

Any updates? I'm considering installing the dual system on my blower motor in the Daytona. I installed the Terminator max on my Tatum with the LS1, it's so much better than the old Delphi system.

 

[Thomas K]

Update. After a couple seasons of running the Holley sniper EFi... we love it. Especially the wife! She loves how it fires right up every time. We have had some great trips on Mohave, Powell, and Pleasant. The throttle response is great. Fuel economy is good. Cold start after winterization is almost instant. Overall I really like the system. The only issue I have with it is sometimes the throttle body does not fully close on one side and it will idle kinda high. I need to get a heavier return spring for the throttle body so it will close all the way. That is something that will wait for a couple months. We plan on selling the Kachina in the spring. We bought a 86 Formula 311 SR-1 with twin 498 ci bbc with bravo drives. My wife and I have ripped out the cabin interior and are doing a little remodel inside. I'm also putting on the new Holley Sniper 2's on the motors. I will start a new thread for that one.