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Thread: Sniper EFI tuning questions & suggestions.

  1. #1

    Default Sniper EFI tuning questions & suggestions.

    I got drive the car today and maybe have 50 miles total drive time. But only about 15 miles since I did the idle screw reset. Here are a few things I'm seeing and hopefully can get some tips on how to address them.

    First off, it looks like my CTS is about 20° cooler than my aftermarket temp gauge. My temp gauge will show between 185° -190°, but the CTS in my Sniper touchscreen will show between 165°-167°. So it's getting hot enough to go through the learning process, but I don't know what other issues the cooler temp might cause.

    1. When I do an initial start, my IAC will be about 5%. However, as soon as I start driving and come to a stop light/sign with the car in neutral or clutch in, then the IAC stays at 0%. It will stay that way until I turn off the car and restart it, then it goes back to between 5%-7%. I'll then start driving, it show 30% will driving, but then back to 0% & stops.

    2. I have the idle set to 800 RPM in the touchscreen. When I initially start the car and let it get warm, it will idle around that RPM. But once I start to drive it and come to a stop, the RPM will stay around 1,100. It never goes back down to the set RPM unless I turn off the car, and restart it. The RPM even stays around the 1,100 range when switching gears.

    3. On initial start, especially when it was cold, is seems as though the EFI isn't getting enough fuel and kind of struggles to start. It does start though. I'm not sure which setting to change that and/or should I wait to get more drive time and maybe this will correct itself?

    Here are other details I wrote down while drive:
    -AFR is in the 13.5-14 range. I'm assuming that's acceptable.
    -Timing is around 12° at idle, and then goes to 36° during driving.

  2. #2
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    Quote Originally Posted by caverman View Post
    First off, it looks like my CTS is about 20° cooler than my aftermarket temp gauge. My temp gauge will show between 185° -190°, but the CTS in my Sniper touchscreen will show between 165°-167°. So it's getting hot enough to go through the learning process, but I don't know what other issues the cooler temp might cause.
    This is not a problem, and it's a typical differentiation of EFI sensors & aftermarket gauges.

    1. When I do an initial start, my IAC will be about 5%.
    Above 5% IAC Position is about what it should be fully warmed up. The IAC Position should be much higher at cold startup.

    However, as soon as I start driving and come to a stop light/sign with the car in neutral or clutch in, then the IAC stays at 0%. It will stay that way until I turn off the car and restart it, then it goes back to between 5%-7%.
    Again, this indicates the primary throttle blades are open too far (idle speed screw in too far).

    I'll then start driving, it show 30% will driving, but then back to 0% & stops.
    If 30% is your IAC Hold Position, then this is normal.

    2. I have the idle set to 800 RPM in the touchscreen. When I initially start the car and let it get warm, it will idle around that RPM. But once I start to drive it and come to a stop, the RPM will stay around 1,100. It never goes back down to the set RPM unless I turn off the car, and restart it. The RPM even stays around the 1,100 range when switching gears.
    Again, this indicates the primary throttle blades are open too far (idle speed screw in too far).
    Does the TPS Position return to 0% at idle/neutral? If not, read the 3rd paragraph of this LINK.

    3. On initial start, especially when it was cold, is seems as though the EFI isn't getting enough fuel and kind of struggles to start. It does start though. I'm not sure which setting to change that and/or should I wait to get more drive time and maybe this will correct itself?
    Learning may self-tune this. If not, I'll have to see what startup tuning parameters are available.

    Here are other details I wrote down while drive:
    -AFR is in the 13.5-14 range. I'm assuming that's acceptable.
    -Timing is around 12° at idle, and then goes to 36° during driving.
    Your specified AFR requires more detail (idle, cruise & WOT).
    http://documents.holley.com/199r10485rev1.pdf (Holley 534-201 Stand-Alone Wideband O2 Sensor Kit - Suggested Air/Fuel Ratios, Page 6)
    Your specified timing requires camshaft duration at 0.50" lift.
    https://forums.holley.com/showthread...8640#post88640 (Target A/F Ratio Table & Base Timing Table Reference)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS T/W 11R 205 heads, 232°-244° duration/.623" lift/114° LSA camshaft, 12:1 C/R, TFS R-Series FTI ported intake, BBK 80mm T/B, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, -6AN fuel system plumbing, Walbro 255 LPH pump, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 M/T Street Comp tires.

  3. #3

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    Quote Originally Posted by Danny Cabral View Post
    Above 5% IAC Position is about what it should be fully warmed up. The IAC Position should be much higher at cold startup.
    Again, this indicates the primary throttle blades are open too far (idle speed screw in too far).
    I'll go back and check all this again in a couple days. We have bad weather coming in right now, and I can't really drive it.

    What I remember is that it was at 5%-7% when warm, it would bounce around between the numbers and I would even occasionally see a 10%-12% for a few seconds, but it would usually settle back down. However, if I then drove it even down the street it would go back to 0%. It would always stay at 0% until I would turn off and restart the car. Then it was back to the ~5%, until I drove it again and it would go back to 0%. It consistently repeated that process at least 4 different times while I drove it this morning.

    I guess what I'll do is let it warm up to the point that the CTS is reading at least 160°. I'll then turn off and restart the car. I'll then back out the Idle screw about 1/4 turn and then restart the car (assuming that's how to do the TPS reset). I'll probably have to go drive it at that point, because on a fresh restart the IAC would be in the correct range.

    Quote Originally Posted by Danny Cabral View Post
    If 30% is your IAC Hold Position, then this is normal.
    I'm assuming that's what the factory set it to. I'm going to leave that one alone unless you think there is a need to change it.

    Quote Originally Posted by Danny Cabral View Post
    Again, this indicates the primary throttle blades are open too far (idle speed screw in too far).
    Does the TPS Position return to 0% at idle/neutral? If not, read the 3rd paragraph of this LINK.
    I took off the return spring I had on the car. That got me to a TPS of 0%, but sitting at Idle I would occasionally see it it flicker over to 1% and the back to 0%. It would only sit at 1% for maybe a second. Sounds like it's right on the border of thinking it's at 1%.

  4. #4
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    Quote Originally Posted by caverman View Post
    I'll go back and check all this again in a couple days. We have bad weather coming in right now, and I can't really drive it.
    Setting the idle speed screw/IAC Position relationship has nothing to do with driving the vehicle. It's a HOT idle adjustment thing.

    What I remember is that it was at 5%-7% when warm, it would bounce around between the numbers and I would even occasionally see a 10%-12% for a few seconds, but it would usually settle back down. However, if I then drove it even down the street it would go back to 0%. It would always stay at 0% until I would turn off and restart the car. Then it was back to the ~5%, until I drove it again and it would go back to 0%. It consistently repeated that process at least 4 different times while I drove it this morning.
    I already addressed this in post #2. Try backing off the idle speed screw a little bit, until the IAC Position is 10% at HOT idle.

    I guess what I'll do is let it warm up to the point that the CTS is reading at least 160°. I'll then turn off and restart the car. I'll then back out the Idle screw about 1/4 turn and then restart the car (assuming that's how to do the TPS reset).
    Perform the idle speed screw adjustment with the engine HOT. Wait until the engine's oil pressure stabilizes to its hot idle pressure.
    http://documents.holley.com/199r11193.pdf (Holley Sniper EFI Quick Start Manual - Idle Setting/Throttle Plate Setting, Page 12)

    I'm assuming that's what the factory set it to. I'm going to leave that one alone unless you think there is a need to change it.
    I'm not asking for assumptions. What is your actual IAC Hold Position?
    http://documents.holley.com/199r11031r.pdf (Holley Sniper EFI Instruction Manual - IAC Hold Position, Page 30)

    I took off the return spring I had on the car. That got me to a TPS of 0%, but sitting at Idle I would occasionally see it it flicker over to 1% and the back to 0%. It would only sit at 1% for maybe a second. Sounds like it's right on the border of thinking it's at 1%.
    I already addressed this in the aforementioned LINK.
    http://forums.holley.com/showthread....3135#post83135 (Related Forum Post)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS T/W 11R 205 heads, 232°-244° duration/.623" lift/114° LSA camshaft, 12:1 C/R, TFS R-Series FTI ported intake, BBK 80mm T/B, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, -6AN fuel system plumbing, Walbro 255 LPH pump, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 M/T Street Comp tires.

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