Results 1 to 4 of 4

Thread: Won't enter closed loop.

  1. #1
    Devin Guest

    Default Won't enter closed loop.

    I am stumped on this one. I am running a Commander 950 MPFI system on a Ford 400. I fired it for the first time a few weeks ago. I verified that it was entering closed loop last week. Then, all of the sudden, it won't go into closed loop any longer. The close loop compensation box stays stuck at 100. All of the conditions for going into closed loop have been met, but it won't do it. I am getting voltage from my O2 sensor (narrow-band), IAC is working, RPM signal is coming through. I am running Ford TFI and am using a Mallory HiFire ignition. Any thoughts?

    Thanks,

    Devin
    Last edited by Devin; 10-30-2010 at 10:58 AM.

  2. #2
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    23,085

    Default

    In the Engine Parameters screen, is "Closed Loop" still selected? (Non-numerical values require a restart.)
    Also, is the "Maximum TPS for Closed Loop Operation" set correctly?

    In the Oxygen Sensor/Closed Loop Parameters screen, is the "Minimum Engine Temp for Closed Loop Operation" met?
    Also, is the "RPM to Enter Closed Loop" set correctly and are any of the O2 Compensation Limits set to zero?
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 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, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 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 tires.

  3. #3
    Devin Guest

    Default

    Thanks. I feel pretty silly. I tried a different map that a friend had for a similar engine. For some reason, it had zeros for all of the negative O2 compensation. This map was on the rich side, so it just wasn't allowing it to take any fuel away.

    One more quick question. What is the best way to get the motor to fire quicker? Mine has to crank for a while (1-2 seconds) before it fires. I have played with the cranking pulsewidth a bit, but it didn't seem to do much. Wanted to see what the experienced users have to say.

  4. #4
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    23,085

    Default

    Quote Originally Posted by Devin View Post
    One more quick question. What is the best way to get the motor to fire quicker? Mine has to crank for a while (1-2 seconds) before it fires. I have played with the cranking pulsewidth a bit, but it didn't seem to do much. Wanted to see what the experienced users have to say.
    Maximize the idle 'throttle blade opening', tune the 'IAC Parked Position' and tune the 'Cranking Pulse Width'.

    Hint: Aside from the starting issue, set all the O2 Compensation Limits to 25%.
    Last edited by Danny Cabral; 12-20-2010 at 09:46 AM.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 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, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 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 tires.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us