Fuel Injection idle question
 

I had the fuel injection system updated from sniper 1.0 to 2.0. When the 1.0 was used the idle was down to 850 RPM and had a great lope sound and the engine was happy set that way. Now with the 2.0, the idle is at 1100 to 1200 RPM. The idle sounds like crap since the RPM's are up. However, the engine idle is fine (Smooth). I asked my mechanic about this and he says this is where the engine is happy. I'm questioning his answer and know nothing was changed on the engine except for the updated Sniper. Doesn't make any sense to me.

Why dont you just go in and set the idle back down to 850 and see how it sounds. Its a simple button click to bring it back up if its unhappy.

Aside from that I would look for a vacuum leak.

Are we talking about hot idle or cold idle?

What is the IAC % when the idle is that high? Are you running timing control through the Sniper?

When you say you updated to 2.0 are you talking about just a software update or did you replace the entire unit?

If the entire unit was replaced then as mentioned you may have to go through the whole IAC adjustment deal, but first I'd go in to the touch screen, as mentioned, and command the idle rpm you want. It's just a few simple clicks of the touch screen.

I run Terminator X so I'm not really familiar with the Sniper system but my suggestion would be to do a TPS AUTOSET and then restart and see if it helps. If nothing was changed mechanically on the throttle body (as in adjusting the idle screw) I'd look for a vacuum leak.

If they raised the idle through the software, just go in and change it back. Also consider that they may have changed the idle timing parameters which could also affect the idle speed.

TPS Autoset
https://youtu.be/3VFPCzpDkaU?si=IeERCxthFn4UmcX-

Sniper Idle adjustments
https://youtu.be/j5Wz_RoXVSI?si=9FY2tAPbVS9Nmbls

Edit: Apparently the Sniper does the TPS autoset automatically every time you cycle the key on/off for 4 seconds or more, so ignore that part of my first suggestion.

I switched from a sniper 1.0 to also running the Holley terminator X and I would bet that your idle issues are coming from that manually IAC adjustment screw on the new linkage….They are very very touchy and it probably got moved just a tiny bit when swapping over …I had to play with mine on my throttle body forever to get it just right

Check the cable adjustment too. Make sure there's slack in it and then reset the throttle stop screw to get it to idle at 850 (commanded in the sniper). You might need to reset it a few times to zero out the throttle position sensor. Set the IAC to about 10% when the motor is hot at commanded idle speed and you're done. If you have idle issues when the motor is cold, you can use the advanced IO to create an IAC offset table to kick the IAC open more when it's cold. I do this on terminator X LS installs, Sniper installs etc... I find it's very much needed on manual transmission cars. Automatics can catch the idle and not stall but it takes a bit of work.

Replaced the entire unit.

If I understand your question, IAC was at 30% when I drove it back from the shop.

I don't trust myself to see if the RPM is 850. I usually screw things up.

We are talking both hot and cold idle.

I watched the video. Looks like even I can't screw it up. I'll try it, but I can tell the system in the video is Sniper 1.0 and Sniper 2.0 on the first screen is different.

Thanks for the replies.

Ah ok, you'll have to start from the beginning then. Where you had the idle screw on your throttle body to set the IAC before is now gone.

I would set the commanded idle rpm where you want with the touch screen, then worry about the IAC number. The number holley tells everyone to shoot for is at hot idle. I like to drive it up and down the street a few miles and get it decently heat soaked, then without shutting off the car, sitting out of gear and idling, I'll set the idle screw until I see 2-5% IAC on the touch screen.