Build Holley Sniper/Desmog Install - Tilda Bogue Service Station
- Thread starter wngrog
- Start date
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@wngrog Terrific work and superior instruction detail. Holley should provide a link on their website for 2300 installs ….
I had installed my Sniper a year earlier and so happy it came out as if you did the job. Almost every detail. My biggest F’up was adjusting the IDLE SCREW ( ha-ha ) you’ve done a perfect job of highlighting this. I’ve tried to pass this along to anyone else I know installing EFI.
I’ve been guided by your recommendations on many other upgrades to my 40 as well as some many guys here using Sniper setups. Thank-you! Whenever the time comes for the next owner, they are going to be thrilled
Did you run an additional return spring for the throttle?
Did you ever need to trim the material on the insulator where it contacts either the head or headers?
Have all of your installs followed a textbook plan on setting the IAC%? Took me several weeks to eliminate the floating % always going back to zero…slowly but always going back to zero
I had installed my Sniper a year earlier and so happy it came out as if you did the job. Almost every detail. My biggest F’up was adjusting the IDLE SCREW ( ha-ha ) you’ve done a perfect job of highlighting this. I’ve tried to pass this along to anyone else I know installing EFI.
I’ve been guided by your recommendations on many other upgrades to my 40 as well as some many guys here using Sniper setups. Thank-you! Whenever the time comes for the next owner, they are going to be thrilled
Did you run an additional return spring for the throttle?
Did you ever need to trim the material on the insulator where it contacts either the head or headers?
Have all of your installs followed a textbook plan on setting the IAC%? Took me several weeks to eliminate the floating % always going back to zero…slowly but always going back to zero
- Thread starter
- #83
Some cars need an additonal spring. It's weird some do. Most don't.
Good question on the insulator. Definitely check to make sure it's not hitting. I use different headers. Some hit. I either grind the header or trim the insulator.
I've had a few that have wandering IACs. Most don't. Not sure why some do.
Thanks for this thread. I bought a rig with an existing Sniper kit and this was helpful to understand the base install. Mine had some idle issues, turns out the IAC was bad and I needed an additional throttle return spring. My base timing was also at 16 degrees so I backed it down to 12 per the range in this thread and it had a better time idling at the target speed.
@open country if I might ask…how did you determine the IAC was bad? Bad meaning poorly adjusted or Bad meaning defective? My sniper is the best fuel system I have used since 1974, running great but did take a few weeks of screwing with it to get a stable IAC setup plus 4-5 Holley tech phone calls… LONG wait times and the music on hold is designed to drive you crazy and want to hang up after 30-40 minutes
After adjusting the throttle screw per the install manual I could never get the IAC to drop below 20% cycle over 160 degrees coolant temp, which led to hanging/high idle. Changing it out solved that at idle, and from what I've read it's fairly common for these to go bad. I got this one on Amazon but kept the old one just in case. Then while driving had some lingering rev hang (unrelated to IAC) that was solved by an additional throttle return spring.
My IAC is within range but have noticed when letting off the throttle pedal the TPS registers a non-zero value between 1% and up to 5%. Seems like a small issue but more of an annoyance as I would expect TPS to return to zero. Is there something I’ve overlooked or should I look into a throttle return spring to assist in achieving 0% TPS at idle?
- Thread starter
- #88
I'd try an additional return spring first.
Can you hook your foot under the pedal and get zero?
Yes using my foot to force pedal up will return TPS back to 0%. Will follow your advice and try a return spring - thanks for the recommendation. I’ve not noticed how you’ve placed throttle return springs on your builds other than the Gulf40 running the RL throttle linkage setup. Curious how you would run a throttle return springs on your more typical setup with throttle cable running in from the front? I briefly tried a return spring in a couple of positions but it didn’t seem to work as intended for me, but I’ve little experience with these so I’ll claim ignorance with a willingness to learn.
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