401 Sniper EFI AF/R

For everything related to using Fuel Injection in an FSJ.
FSBOB
Posts: 23
Joined: Fri Jun 23, 2017 6:30 pm
Location: Minnesota

401 Sniper EFI AF/R

Postby FSBOB » Fri Nov 30, 2018 1:01 pm

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
Posts: 1389
Joined: Tue Jul 14, 2015 8:59 pm
Location: Mesa, AZ

Re: 401 Sniper EFI AF/R

Postby az chip » Wed Dec 05, 2018 4:29 pm

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/ Rusty 4" Spring lift/ Bulltear oil adapter/K&P Engineering Oil Filter/ NP 208/ Serehill Light Harness/ H4 Headlights/ Evil Twin Fab Roof Rack and sliders/ Ross mirror mounts.

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KJ Ryu
Posts: 838
Joined: Sun Jun 10, 2012 8:03 am
Location: Casper

Re: 401 Sniper EFI AF/R

Postby KJ Ryu » Sat Dec 08, 2018 2:16 pm

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
Posts: 1389
Joined: Tue Jul 14, 2015 8:59 pm
Location: Mesa, AZ

Re: 401 Sniper EFI AF/R

Postby az chip » Sun Dec 09, 2018 12:47 am

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/ Rusty 4" Spring lift/ Bulltear oil adapter/K&P Engineering Oil Filter/ NP 208/ Serehill Light Harness/ H4 Headlights/ Evil Twin Fab Roof Rack and sliders/ Ross mirror mounts.

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babywag
Posts: 1055
Joined: Fri Jun 08, 2012 7:29 pm
Location: Land of Fruit Loops & Coconuts

Re: 401 Sniper EFI AF/R

Postby babywag » Sun Dec 09, 2018 1:42 pm

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) '90 GW (aka JunkBucket) both fuel injected.
email me I never receive PM notifications and frequently do NOT see them.

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Renodemona
Posts: 767
Joined: Wed Jan 01, 2014 9:55 pm
Location: Sparks, NV

Re: 401 Sniper EFI AF/R

Postby Renodemona » Tue Dec 11, 2018 11:16 pm

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!?"
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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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1972 Wagoneer 'Meredith' 360/TH400/D20
FiTech Go EFI
4" Alcan Springs, HEI Dizzy
-------------------------------------------------------------
2018 Cherokee Trailhawk V6 'Sedna'


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