Sniper EFI AFR Spike (1 Viewer)

[74GreenFJ]

Guru's (@FJ60Cam @wngrog @GA Architect and others!),

I'm trying to resolve a couple slight annoyances that I'm having with my Sniper.

1) When the 40 is cold or warm and I decelerate to a stop, the AFR jumps up to 18-20 while the idle goes to about 75 less than target. IAC is zero during that time. It doesn't stall but sure feels close before it catches itself
-I have adjusted the idle ramp down delay to hang slightly longer with no change. I also changed the cam setting to mild. Shots in the dark if nothing else per Cameron's guidance to another post.

2) During the initial start I have to crank it for about 8 seconds before it fully fires off. The engine will give one good attempt, but seems like it may not be getting enough gas then continues to turn over before starting.
-I have adjusted the prime to 150% with no change


I wanted to consult the wealth of knowledge before I play with settings and make the issues worse. Happy to provide whatever extra data that would help with the troubleshooting. Thanks in advance for the help gents!

 

[wngrog]

That AFR spike is so common. I have one that does it and 2 that don’t. Exact same settings. Mine actually dies most of the time on the first stop sign on my road so the fact that yours does not die is actually ...... ok?

Keep bumping that prime. I had one that did that and I think I have the prime at about 200 now and it worked.

I’ve found on one that will fire but not start that if I complety recycle the key for a fresh prime it will start on try two every time.

it’s crazy I have 3 trucks with Snipers with mostly the same setup and all 3 have their own quirks.

 

[74GreenFJ]

That AFR spike is so common. I have one that does it and 2 that don’t. Exact same settings. Mine actually dies most of the time on the first stop sign on my road so the fact that yours does not die is actually ...... ok?

Keep bumping that prime. I had one that did that and I think I have the prime at about 200 now and it worked.

I’ve found on one that will fire but not start that if I complety recycle the key for a fresh prime it will start on try two every time.

it’s crazy I have 3 trucks with Snipers with mostly the same setup and all 3 have their own quirks.

Thanks for the info Nolen!

 

[JDNs78FJ40]

@74GreenFJ curious if you were able to solve your issues? I have some of the same issues. I have to give mine a little throttle on every start up, cold or hot Did you bump up the prime on yours? If so, did that solve your start-up issues.

 

[74GreenFJ]

@74GreenFJ curious if you were able to solve your issues? I have some of the same issues. I have to give mine a little throttle on every start up, cold or hot Did you bump up the prime on yours? If so, did that solve your start-up issues.

Sure did. I might be around 180% now. No issues and it seemed to sort out the AFR spike somehow as well. More learning maybe?

 

[JDNs78FJ40]

Awesome! I’m going to bump mine up and see what happens. What kind of IAC percentage range are you seeing once at operating temp? I’m in the 6-10% range.

 

[wngrog]

Awesome! I’m going to bump mine up and see what happens. What kind of IAC percentage range are you seeing once at operating temp? I’m in the 6-10% range.

That’s correct

 

[74GreenFJ]

That’s correct

I’m at 20 while cruising around at highway speeds and then sitting at idle it’s at 0 by the time it ramps down.

 

[wngrog]

I’m at 20 while cruising around at highway speeds and then sitting at idle it’s at 0 by the time it ramps down.

20 is good there. If you see spikes above 20 you may have fuel filter or O2 issues.

On the zero. You should play with that to get it in the recommended zone. If it gets there real slow you will find a very small adjustment of the screw will get you there

 

[74GreenFJ]

20 is good there. If you see spikes above 20 you may have fuel filter or O2 issues.

On the zero. You should play with that to get it in the recommended zone. If it gets there real slow you will find a very small adjustment of the screw will get you there

I may shoot you a message to describe/send a pic of said screw.

 

[wngrog]

I may shoot you a message to describe/send a pic of said screw.

Go to your Sniper manual and do the AFR procedure. It’s a perfect description.
Many people think it’s a RPM screw like a carburetor but it’s allows the proper AFR so the computer can go to the RpM you set in the Wizard.

 

[JDNs78FJ40]

Bumped mine up to 200 and fires right up. Now I just need to call Holley and ask them why the ECU glitches and sometimes freezes. Other than that this thing purrs like a kitten!

 

[74GreenFJ]

Bumped mine up to 200 and fires right up. Now I just need to call Holley and ask them why the ECU glitches and sometimes freezes. Other than that this thing purrs like a kitten!

Great! Also thanks for the heads up from you and @wngrog for the IAC setting. Got it dialed in to about 6-7% now and it’s so much better. Didn’t know what I didn’t know!

 

[mrboatman]

Bumped mine up to 200 and fires right up. Now I just need to call Holley and ask them why the ECU glitches and sometimes freezes. Other than that this thing purrs like a kitten!

If you are talking about the 3.5" display screen mine was doing some wacko things and Holley sent me a new one and it works great

 

[JDNs78FJ40]

If you are talking about the 3.5" display screen mine was doing some wacko things and Holley sent me a new one and it works great

Yes, the screen. I’ll give Holley a call. Thanks.