[78 Elk]

I restarted and got the temperature up to 190. The IAC was at 28. I tried pumping the throttle and it stayed the same. So I made an adjustment and got the IAC down to 4. I stepped on the throttle and it didn't change. I shut it off and restarted right away it went back to 28. I tried stomping on the throttle and it made no difference. If I hold the accelerator down then the number drops to 0. The situation is that the screw ends up in the same place.

 

[inverse121]

Of course the IAC drops to zero if you hold the throttle down, you have opened the butterfly more and the IAC isn't needed.

Maybe try driving it some if you haven't and let it learn rather than just starting it, adjusitng it and shutting it down repeatedly. Might not hurt to do relearn on the IAC and TPS or even a full reset on the ECM and sensors after all this fiddling and restarting over the past few days.

There are other advanced settings with the IAC such as startup hold and decay and maybe yours are out of whack, but I doubt it and I don't have the knowledge to advise you on those settings.

 

[78 Elk]

Thank you very much for your help. I hope to get it on the road tomorrow. I was confused about the IAC setting and can’t get it to stay where I set it at idle. At least it starts up without pushing on the accelerator.

 

[78 Elk]

I took it out on the road again today. It ran well, but the IAC was at 10 or more at stop signs. The gas gauge appears to be working, in 2 trips it dropped a quarter tank. I shut it off when I got home, went in and opened the garage door. I restarted it and drove it in the garage. I put the transmission in park, then the engine ran rough as heck, so I shut it off. I'll have to figure out what is going on.

 

[squag27]

I'm wondering if you might be having some RFI interference issues on yours. Before I wrapped all my Sniper wires in reflective sleeves, I had a ton of idle issues with mine.

 

[78 Elk]

Thank you. How do I figure this out?

 

[squag27]

Thank you. How do I figure this out?

Take a datalog. Call Holley and send it to them or you can just send it to me too.

 

[78 Elk]

Thank you. How do I get a catalog? I don't have any experience at this but I'm willing to learn.

 

[78 Elk]

A little update. I just started up the 78 El Camino again and the idle was better than when I got home. The IAC was over 20. I tried adjusting the screw again and got the IAC down to 8-15 and it ran better. So I shut it off and restarted it again and the IAC was over 20. So I tried to adjust it again and it ran better. I shut it off again and restarted it but the IAC was over 20 again. So while it was running I got back in the El Camino I pushed the accelerator down quickly and made no difference. So while it was running I stepped on the accelerator and held it down raising the rpms by a hundred then the IAC dropped to the setting that I set it for. The idle improved with this setting.

 

[78 Elk]

I started up the 78 El Camino in the garage today and the IAC was back being at 100 and as the engine warmed up, it dropped to 20.

 

[78 Elk]

I called Holley Performance today and I asked questions about the IAC. He suggested to try lowering the rpms a little. So I changed the rpm setting to 750. Then I started up the 78 El Camino again today and the IAC dropped to 69 after it got warm the IAC dropped to 20. Then I held the throttle down for a bit then let up and the IAC was between 4 and 6. I checked for interference from the spark plug wire by the sensor and there wasn't any spark plug wires close to it. I have a couple other things I need to check, I'll have to get someone around here to help me check it. I appreciate all of your help, it's been awesome. Thank all of you.

 

[78 Elk]

How do I check the fuel pressure at the Sniper EFI system?

 

[78 Elk]

I lowered the RPM setting on the Sniper EFI system again today. I lowered it to 700 RPMs. It started right up without touching the accelerator. The IAC got down to 20 until I held the accelerator down, then it dropped to 4-6. The person I spoke with at Holley Performance told me that the reason the IAC number is high is the system is responding putting more air in ,cause it detects more fuel. What tool is available to check the fuel pressure at the Sniper, from the fuel pump in the gas tank? The surprise to me is that starts without using the accelerator, even at the lower RPMs.

 

[78 Elk]

Where should the Rostra cruise control connect on the Sniper EFI?

 

[78 Elk]

If your plates line up on the Sniper EFI how do you control the IAC?

 

[Caballero Joe]

I'd like to help, but I don't understand what you're asking.
What plates? IAC is Idle Air Controller

The YouTube sent to you a couple of weeks ago gave a step-by-step explanation on how to set your IAC. Did you follow the instructions in the video?

If you carefully followed the procedure and are still having idle or IAC issues, you may consider contacting Holley. It's possible, you could have a bad IAC. Holley technical assistance is very helpful

 

[78 Elk]

Thank you. Holley told me that the screw adjuested the plates in the Sniper EFI. He told me that it sounded like it was adjusted properly. He then told me I need to check the fuel pressure cause if it’s too high it will make it add more air to accommodate it. I’m going to have to see if I can find my pressure gauge to see what pressure the fuel pump is putting out to see if it’s over supplying fuel to the Sniper.

 

[78 Elk]

This question maybe already answered, but is the IAC number supposed to be under 10 at after warmed up at idle or while on the road?

 

[78 Elk]

I started up the 78 El Camino again today. I looked down on the butterfly's and fuel looks the same in each barrel. I played with the screw again and nothing changed on the IAC. I've tried adjusting the RPMs and nothing changed with the IAC. I tried putting my finger in the IAC hole on top of the Sniper and nothing happened. After it's warmed up the IAC holds at 20 until I push the accelerator down for a bit then let up then it drops 5-10.

 

[fauxrs]

This question maybe already answered, but is the IAC number supposed to be under 10 at after warmed up at idle or while on the road?

While cruising it will be in its rest position. Usually 30. You can’t set IAC accurately until it’s warmed up. So yes the IAC should be at its setting when warm and idling