Sniper Cold Tuning

For everything related to using Fuel Injection in an FSJ.
Post Reply

Topic author
1979bettywhite
Posts: 547
Joined: Tue Jul 25, 2017 8:14 am

Sniper Cold Tuning

Post by 1979bettywhite » Fri May 08, 2020 8:03 am

First off, once up to temp, my system runs flawlessly.

On cold start, no real issues other than the initial first drop (2-3 seconds) after turning over will cause the system to go lean just for a second, but it will catch itself and go back to a richer state as it warms up, eventually reaching target AFR.

If I go out for a drive with the engine cold, releasing throttle will usually cause things to go back to a momentary lean state as it returns to idle, then the system will catch itself and go back to normal AFRs. As it continues to warm, this gets to be less and less of an occurrence. Once up to moderate temp (+140 or so) no real issues. Over 160 all issues are gone.

Have any of you fine tuned the Sniper system to run better when cold? From reading things out there, it seems most of this can be tuned via the Coolant Enrichment Table. I have never tuned an EFI system via software. Just some basic tuning on the 3.5" LCD screen.

I guess maybe the easiest answer is to go out and grab a couple data logs and send them over to Holley? But I would like to learn what is happening and how to correct it at the same time.

Any thoughts?

User avatar

ghcoe
Posts: 1074
Joined: Sun Nov 03, 2013 6:39 am
Location: SW Idaho

Re: Sniper Cold Tuning

Post by ghcoe » Mon May 11, 2020 5:29 pm

I wonder if it is normal. Lean running will make the engine warm faster. Of course in general you don't want a lean mixture under load, but maybe under no load situations it is beneficial to warm engine up faster.
SW Idaho Overlanding Facebook: https://www.facebook.com/SWIdahoOverlan ... page_panel
SW Idaho Overlanding Youtube: https://www.youtube.com/channel/UCYuRx2 ... wVwZJ5oztg
1977 Jeep Cherokee WT
All-Terrain T/A® KO2
Safari Kit
Factory Brush Guard
Factory Tire Carrier
Custom Roof Rack


Topic author
1979bettywhite
Posts: 547
Joined: Tue Jul 25, 2017 8:14 am

Re: Sniper Cold Tuning

Post by 1979bettywhite » Tue May 12, 2020 8:02 am

Not sure. I am getting a usb sd card reader today and will grab a couple of data logs and send them to Holley. Also need them to possibly tune it for the progressive linkage. I assume it is getting too much fuel at less than 40% throttle, since the tune is based on both butterflies opening at the same time.


KJ Ryu
Posts: 991
Joined: Sun Jun 10, 2012 8:03 am
Location: Casper

Re: Sniper Cold Tuning

Post by KJ Ryu » Wed May 20, 2020 4:15 pm

You have to reset the tune when you install the progressive linkage. Should have been instructions with the linkage.
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


KJ Ryu
Posts: 991
Joined: Sun Jun 10, 2012 8:03 am
Location: Casper

Re: Sniper Cold Tuning

Post by KJ Ryu » Wed May 20, 2020 4:19 pm

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


Topic author
1979bettywhite
Posts: 547
Joined: Tue Jul 25, 2017 8:14 am

Re: Sniper Cold Tuning

Post by 1979bettywhite » Wed May 20, 2020 4:30 pm

Thanks. That is what I used as well when I installed mine. I have also gone in and edited my AE Correction vs. TPS to match this graph:

https://forums.holley.com/showthread.ph ... tter/page9

Post #88

Also, this was helpful in explaining a bit for me:

https://www.youtube.com/watch?v=ap2tdGnrmxw

I moved my graph up a bit closer to 40 before the fuel starts coming in heavier. My secondaries come in around 48. Have had a couple drives so far and it seems to run a bit better. Although I am still looking for someone to help me fine tune my particular system and fuel map and then limit the learning after that.


KJ Ryu
Posts: 991
Joined: Sun Jun 10, 2012 8:03 am
Location: Casper

Re: Sniper Cold Tuning

Post by KJ Ryu » Wed May 20, 2020 4:59 pm

I haven't gone beyond the basic tuning on mine. Too many exhaust leaks, and now the torque converter is rattling something fierce, so it isn't even being driven.
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

User avatar

Moosehead
Posts: 31
Joined: Wed Jun 20, 2018 9:13 pm
Location: Mountain West

Re: Sniper Cold Tuning

Post by Moosehead » Wed Nov 24, 2021 2:08 pm

Betty, did you ever get the cold tuning figured out? I’m having a similar outcome with a new Sniper in a 401. She otherwise is running great. Have adjusted idle, and FAR across the spectrum, but have yet to do the progressive link.
‘78 Wagoneer
401 with street cam, heads, headers, Holley Sniper EFI, rear discs, Alcan springs, Trucklite LED headlights

User avatar

Moosehead
Posts: 31
Joined: Wed Jun 20, 2018 9:13 pm
Location: Mountain West

Re: Sniper Cold Tuning

Post by Moosehead » Tue Dec 07, 2021 7:02 am

Chris from EFI System Pro had the best start up tune explanations in below attachment, which also break it down from both handheld adjustments and software. Chris also reduces the pucker factor quite a bit. The handheld was sufficient for this noob but still allowed small tweaks in IAC Park, IAC Hold, and IAC Decay times to help with Cold Start challenges.

https://www.efisystempro.com/efi-pro-ha ... -x-stealth
‘78 Wagoneer
401 with street cam, heads, headers, Holley Sniper EFI, rear discs, Alcan springs, Trucklite LED headlights

Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests