Holley Sniper EFI Planning and Installation

[Cooter_76]

Looks like other Sniper owners have experienced high PSI, and the solution from Holley is to ship them a new regulator: https://forums.holley.com/showthread.php?20392-High-Fuel-PSI
I'm going to give them a call in the morning.

 

[Cooter_76]

Called Holley tech support 1st thing this morning. When I mentioned the high fuel pressure the tech immediately said "let me get your mailing address." They're going to send me a new regulator and regulator cover. Apparently some of the regulator covers weren't machined properly and they put too much pressure on the regulator.
The new parts should arrive by Wednesday, which will give me time to get it installed right before the LEBC Round Up this weekend! Hoping this cures what ails me.
Thanks for all the advice and suggestions!

 

[Cooter_76]

In case anyone is interested, here is a (mostly) complete list of all the things I purchased for the Sniper Install. This list doesn't include shipping or taxes, and I'm sure there are a few odds & ends I missed.

 

[tirewater]

In case anyone is interested, here is a (mostly) complete list of all the things I purchased for the Sniper Install. This list doesn't include shipping or taxes, and I'm sure there are a few odds & ends I missed.

Interesting, it makes the Holley Sniper Master Kit price competitive @$1249.95

https://holley.com/products/fuel_sy...i_master_kits_with_fuel_system/parts/550-511K

Of course the kit doesn't include the brake line or kickdown cable that you purchased.

 

[Cooter_76]

Interesting, it makes the Holley Sniper Master Kit price competitive @$1249.95

https://holley.com/products/fuel_sy...i_master_kits_with_fuel_system/parts/550-511K

Of course the kit doesn't include the brake line or kickdown cable that you purchased.

Absolutely. If the master kit had been available, I probably would have ordered it. The pricing is a good value, ESPECIALLY when you take into consideration the time and effort involved in figuring out what pieces are needed, running to various parts stores and/or making multiple purchases online.

One thing I'd forgotten to include on my list was a fuel pressure gauge, which I've since updated. If I'd installed a pressure gauge in the beginning it probably would have saved a lot of time and headache in the troubleshooting dept.

 

[Cooter_76]

After pacing back & forth by the front door this afternoon, the UPS guy finally came after I left for Costco.
Here's a pic showing the old (left) vs new (right) regulator covers:

I didn't see any difference in the thickness of the mounting surface, but the little rubber bumper that pushes against the regulator is noticeably shorter.

And here's a pic showing the old (left) and new (right) regulators.

The old one appears to have been depressed by that rubber bumper.

Fuel pressure is steady at 60-61 PSI now!

 

[73azbronco]

And it drives great, right????

 

[crutch]

Congrats and thanks for sharing the info. I'm going to be doing this in next few weeks and will be on lookout for this issue.


Sent from my iPhone using Tapatalk

 

[Cooter_76]

And it drives great, right????

Well...

It runs really well, but I went to a nearby gas station to throw a few gallons in it. When I got back in I had to bury the throttle while cranking to get it it to start. Same story after I got it back in the garage. When starting the engine, I turn the key to "Run" and the fuel pump comes on for a few seconds to prime the system before turning the key to "Start." The fuel pump doesn't sound right when doing this after the engine is warm. ?:? The engine is also still idling high (850 RPM, when the computer is set at 750.)

Now that I have the fuel pressure where it's supposed to be, I'm going to start from scratch with the initial startup wizard and try to get the idle down where I want it.

Stay tuned.

 

[73azbronco]

My guess is resetting it to new, untouched on the computer and let the system learn all over. It was trying to learn with 100psi

 

[Ol'Blue]

Cooter, I would do what 73AZ says and restart the wizard and see if that helps.

If you still have starting issues and you think its flooding try adjusting the cranking fuel in the advanced fuel settings. Subtract fuel from the cranking fuel on the part of the graph at the temperatures it is hard to start. Use small increments. I reduced mine by 2 at operating temp and it helped.

If your idle is still too high try:

navigate to the “Idle speed curve” on the handheld:

Tuning > Advanced > Adv. Idle > Idle Speed > Idle Speed Curve

Once there, make sure that the first dot on the left hand side of the curve (at -40°F isn’t way lower than the rest of the dots) if it is raise it up in line with the rest.

Both of these were suggestions from Holley tech when I was having similar issue.

Good luck!

 

[Cooter_76]

Cooter, I would do what 73AZ says and restart the wizard and see if that helps.

If you still have starting issues and you think its flooding try adjusting the cranking fuel in the advanced fuel settings. Subtract fuel from the cranking fuel on the part of the graph at the temperatures it is hard to start. Use small increments. I reduced mine by 2 at operating temp and it helped.

If your idle is still too high try:

navigate to the “Idle speed curve” on the handheld:

Tuning > Advanced > Adv. Idle > Idle Speed > Idle Speed Curve

Once there, make sure that the first dot on the left hand side of the curve (at -40°F isn’t way lower than the rest of the dots) if it is raise it up in line with the rest.

Both of these were suggestions from Holley tech when I was having similar issue.

Good luck!

Thanks for the advice. I just went through the wizard again and took it for an extended test drive. It still won't idle below about 820 RPM while sitting in Park. Could be a vacuum leak, but I've replaced everything I can think of except the intake manifold seals. It didn't have the hot start issue today. I suspect it is flooding when that happens. Next time I experience it I may make changes to the cranking fuel, as you suggested. There are also some fuel prime settings I might mess with. I did have to re-adjust the Idle Speed Curve after running the wizard again.
For now, I'm calling it good enough to throw on a trailer and take to the LEBC Round Up tomorrow. That will be the real test!

Any update on your stalling issue? That's a real head-scratcher!

 

[Ol'Blue]

Holley thinks its RF noise coming form the dizzy, so Im trying air cleaner spacers and a smaller air cleaner to get it away from the dizzy. I need to update my post today. Good luck!!

 

[73azbronco]

RF noise coming from dizzy, which every car out there has.

What did Holley say to that? If this was a "thing", then Fitecs and everybody else would be acting the same way. So I bet a defective holley unit. Particularly if it idles wrong.

Whats your vacuum at idle? Did it idle at lower RPM before the holley, all things being equal?

Might try the vacuum leak check spraying around intake with wd40 or carb cleaner.

 

[Cooter_76]

Whats your vacuum at idle? Did it idle at lower RPM before the holley, all things being equal?

Vacuum at idle is 15-16. I've never been able to get much more than that, even when playing with timing. No clue what cam it has or whether it's ever been bored. It idled at about 750 with the carb. If there is a vacuum leak, I may have been able to "tune around it", whereas the EFI is trying to fight it?

Might try the vacuum leak check spraying around intake with wd40 or carb cleaner.

According to this site, that method may not work with EFI.
Back in the days of carburetors, old-timers would carefully spray a little carb cleaner around the base of the carburetor flange and vacuum lines to look for a leak. This worked because it changed enriched the air/fuel ratio and change the idle slightly when the leak sucked in the flammable spray. Because the Sniper ECU can detect and correct a change in air/fuel ratio before it can impact the RPM of the engine, it is unlikely this will work for you.

 

[73azbronco]

I'm skeptical it can correct idle faster than the fluid finds any leaks, but I'm not the expert. I mean come on it has to make idle change a little or it wouldn't have anything to correct right? Plus, it mentions base of carb, and while that is one spot to check, I'm talking the runners along the heads, front back, any other vacuum lines you have. To check for leaks in the intake gasket. Your vacuum sounds OK. If you could idle it lower then it points once again to a holley issue. Give them a call again and ask why their unit cant get below 850 but your cheapo carb could.

BTW, this check is what I used on BMW's using fuel injection to find intake leaks, sooooo.

 

[RangerRob]

I think you would possibly notice a difference if the leak is around the carb base. Easy to test I would think by spraying some cleaner (or whatever you are using) above the throttle plates and seeing what happens.

On the subject of chasing possible vacuum leaks, I'm not sure spraying anything around the front and rear intake to block gaskets (or however it was sealed) will do anything to alter the combustion process. Pretty sure those just seal the bottom of the intake to the block and would therefore only be under crankcase conditions, right? Anything sprayed around there seems like it would have a hard time getting into the combustion chambers. If that is the case, how would you go about testing those areas for leaks?

 

[Cooter_76]

Had a great time at the LEBC Spring Round Up this past weekend! The Sniper performed very well. It never stumbled or died while rock crawling like the Edelbrock did (granted, I stick to the Level 2 stuff.) Even when the engine got a little hot (227 deg) it still idled and ran smoothly.
There were probably two instances where the engine did not fire on the very first crank. Both times I don't think I had let the fuel pump prime enough. The pump is very quiet outside. The idle is still a bit high, so I need to work on that.
Overall, I'm a happy camper!

 

[73azbronco]

Might you try adjusting the fuel pressure down 10PSI and see how it idles? Drives? I'm still surprised they sent you parts to take their brand new unit apart and fix yourself.

 

[Cooter_76]

Might you try adjusting the fuel pressure down 10PSI and see how it idles? Drives? I'm still surprised they sent you parts to take their brand new unit apart and fix yourself.

The system calls for 60 PSI. With the new regulator and cover, that's right where it sits. The regulator is not adjustable.