401 Sniper EFI AF/R

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FSBOB
Posts: 23
Joined: Fri Jun 23, 2017 6:30 pm
Location: Minnesota

401 Sniper EFI AF/R

Post by FSBOB »

Hi all,
I've recently rebuilt my 401 and have been trying to get my fuel injection dialed in better. I've been running the stock settings that came with the Holley system since I installed it. I know it's been running rich and want to get it set where it's running better without endangering the engine. What have you guys been running as far as air fuel ratio in your rigs? I'm currently set at 13.7 at idle, 14.2 at cruise, and 12.7 at WOT. Thanks for your contributions.
1976 Jeep J20 401, T15, Dana 20, Holley Sniper EFI, Hedman Headers, MSD Ready-to-Run Ignition, 33" Cooper MTP's :fsj:
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az chip
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Location: Mesa, AZ

Re: 401 Sniper EFI AF/R

Post by az chip »

I would answer but have not got down to that point in tuning yet. Although idle seems fine and cruise looks like mine on my 360.
'81 Cherokee Chief 81 WT Chief/MSD 6/Holley Sniper/ Rusty 4" Spring lift/ Bulltear oil adapter/K&P Engineering Oil Filter/ NP 208/ Serehill Light Harness/KC LED Headlights/ Evil Twin Fab Roof Rack and sliders/ Ross mirror mounts.

KJ Ryu
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Re: 401 Sniper EFI AF/R

Post by KJ Ryu »

It shouldn't be running rich with those settings. My guess is that, like me, you got a defective O2 sensor. My original died a couple of months after installing EFI.
Ron

2005 KJ, Hit-n-Run, 2am 6-17-2012, Totaled. :mad:
1977 SJ J10, 4v360, T18, D20, 37x14s, SOA & SF on tons, still ugly.
1978 SJ Wagoneer, 4v360, QT, 33x12.5s, lift by Sawzall :-bd NOT Running :(
1977 SJ J10, SniperEFI 401, QT, D44s, 31X10.5s :fsj:
2006 KJ
Mars wrote:One man's trans leak is another's penetrating oil :D
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az chip
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Location: Mesa, AZ

Re: 401 Sniper EFI AF/R

Post by az chip »

KJ Ryu wrote:It shouldn't be running rich with those settings. My guess is that, like me, you got a defective O2 sensor. My original died a couple of months after installing EFI.
I think they all die from excessive fuel washing over them on initial set up.
'81 Cherokee Chief 81 WT Chief/MSD 6/Holley Sniper/ Rusty 4" Spring lift/ Bulltear oil adapter/K&P Engineering Oil Filter/ NP 208/ Serehill Light Harness/KC LED Headlights/ Evil Twin Fab Roof Rack and sliders/ Ross mirror mounts.
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babywag
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Location: Land of Fruit Loops & Coconuts

Re: 401 Sniper EFI AF/R

Post by babywag »

FSBOB wrote:Hi all,
I've recently rebuilt my 401 and have been trying to get my fuel injection dialed in better. I've been running the stock settings that came with the Holley system since I installed it. I know it's been running rich and want to get it set where it's running better without endangering the engine. What have you guys been running as far as air fuel ratio in your rigs? I'm currently set at 13.7 at idle, 14.2 at cruise, and 12.7 at WOT. Thanks for your contributions.
13.7 @ idle is way too rich IMHO
14.2 @ cruise is ok-ish but still little rich
12.7 @ WOT is fine

I'd bump both idle & cruise up like 14.3 and 14.5
Only way you'll "hurt" the engine is if you go way lean for an extended time period.
-Tony
'88 GW (aka Babywag)
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Renodemona
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Location: Sparks, NV

Re: 401 Sniper EFI AF/R

Post by Renodemona »

I have the GoEFI, but my numbers are similar though usually around 14.5 cruising around, 14 or so idle.
"Wait, what's on fire!?" KJ7TCT
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1976 Cherokee w/t 'Susan' 401/TH400/QT(PT)
FiTech Go EFI, Edelbrock Performer intake
3" Rough Country Springs, HEI Dizzy
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2018 Cherokee Trailhawk V6 'Sedna'

Jeepin87
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Joined: Mon Jan 28, 2013 12:31 am

Re: 401 Sniper EFI AF/R

Post by Jeepin87 »

401, stock low comp engine, performer intake, .480/224* @.050 cam
Idle 13.8
Cruise 14.7
WOT 12.6

I haven't fine tuned yet but it runs really well. I can't go leaner at idle or it stalls out when I put it in gear.
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babywag
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Re: 401 Sniper EFI AF/R

Post by babywag »

iac needs adjustment or isn't working properly if it stalls from park to drive
-Tony
'88 GW (aka Babywag)

Jeepin87
Posts: 14
Joined: Mon Jan 28, 2013 12:31 am

Re: 401 Sniper EFI AF/R

Post by Jeepin87 »

babywag wrote:iac needs adjustment or isn't working properly if it stalls from park to drive

Nope, IAC is perfect (at least the numbers I'm seeing). I don't carry as much vacuum as most flat landers and my cam is a little hotter than most run in their FSJs (although it is NOT considered a hot cam).

With that being said all of my 401 rigs have liked to run a little rich at idle. The 360s and 6cyls have been happy with a leaner mix though.


Edit:
You have a SNIPER system on a rig in Cali? How did you pass the visual?
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Moosehead
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Joined: Wed Jun 20, 2018 9:13 pm
Location: Mountain West

Re: 401 Sniper EFI AF/R

Post by Moosehead »

Just upgraded EFI from a buggy FAST unit to the Holley Sniper on a 401. Very pleased with the Sniper thus far and its built-in fuel pressure regulator, and cleaner setup. Unit looks and feels way more robust, and Waggy is running really nicely.

I also adjusted AFR stock settings mentioned in OP closer to BabyWags suggestions, and took down idle RPM to 750. The old girl purrs until giving her throttle and MPG’s are closer to 10 rather than 8.5.

Have considered going to the progressive link to sequence the primary and secondary throttle butterflies, but she is so fun to wheel around as is. Other drivers genuinely seem surprised when being passed by the Wag.

Much appreciate the knowledge shared above and on other Holley Sniper threads.


Sent from my iPhone using Tapatalk Pro
‘78 Wagoneer
401 with street cam, heads, headers, Holley Sniper EFI, rear discs, Alcan springs, Trucklite LED headlights
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