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Thread: Sniper never worked right out of box.

  1. #1

    Post Sniper never worked right out of box.

    Good afternoon everyone. I could use some help. I got the Sniper unit almost a year ago. Installed on my '69 Chevelle with a 350 engine with a Edelbrock Air-Gap intake a HEI distributor and the Holley 12-303 fuel pump. It fired right up, so I tried to take a ride and as soon as I pulled out of the driveway and pressed on the gas, it just backfired and ran terrible. So I've been reading the forums and trying to figure the problem myself. Installed new plugs new plug wires new distributor cap and coil. No help still running bad. all the injectors are working. Installed a fuel pressure gauge and the pressure is right below 60 psi. I'm about at my wits end. I've attached a datalog and my Global File all the sensors are reading correctly and I went down the troubleshooting guide and followed the steps. Even did compression test on engine to make sure that no problems with internals of the engine. The car ran great with a QuadraJet and wanted to make the car a little more civil that's why I added the fuel injection. So thank you in advance to anyone who could help.
    new datalog.zip
    new datalog.zip
    4150_4_ZAA.sniper.info.txt

  2. #2
    Join Date
    Oct 2017
    Location
    Los Angeles
    Posts
    347

    Default

    You did not upload your GCF correctly. You uploaded a .txt document which is a easy mistake. Looking at your datalog, one of the first things I would do is make sure your IAC is set correctly. The IAC never gets below 16% and you're doing a lot of idling in this datalog and your engine is up to temperature. I'd get the engine above 160°F and set your IAC correctly first & foremost. The IAC needs to be set between 2% & 10%. I personally like it between 2% & 5%, but adjust the IAC to suit what your engine likes and let us know how it goes.

  3. #3

    Default

    Thank you for the help. OK, I reset the IAC and took this datalog. Does any thing else look off to you?
    sniper_0009.zip

  4. #4
    Join Date
    Oct 2017
    Location
    Los Angeles
    Posts
    347

    Default

    Did the car drive any differently now that you reset the IAC? Also, what percentage did you set the IAC too?

  5. #5

    Default

    You're super lean and it looks like your Closed Loop Compensation is capped at 50%. So your fuel map was built super lean and with the adjustment capped off the system can't solve the problem. If you don't know how to fix the tune, then you should probably just start over and use the Wizard to build a new tune.

  6. #6

    Default

    OK. Thanks very much for the help. I reset the IAC to 8% didn't seem to help much. I'll take your suggestion and disconnect the battery for a time and start over with the Wizard as you mentioned.

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