Page 3 of 3 FirstFirst 123
Results 21 to 24 of 24

Thread: Going lean after start.

  1. #21
    Join Date
    Dec 2009


    My Holley 534-10 CTS is accurate. I've also heard good reports from using a Standard Motor Products TX3, ACDelco 213-928 & Delphi TS10075 CTS. (Replacement Sensors For Holley EFI - Auto Parts Store)
    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.

  2. #22


    So consensus seems to be my CTS sensor is operating in too "tight" of a range. I can try a new one. Datalogged cold start this morning after the truck sat 10 hours. CTS read 102°F with MAT at 90°F. Thermometer on the garage wall read 75°F. Starts good, but initially rich then a bit lean for awhile. I'll play with the start enrichment tables to get it better later, unless it's related to another problem.

    Also attached a datalog of part of my drive to work. It's only a couple miles so it doesn't get into Learn mode, but you can still see the lean spots I get. Plan to drive it more then smooth the fuel table if there are no other suggestions. Thanks all. apr 2 cold apr 2 drive Mar 31 20

  3. #23


    It won't go in to Learn mode until a Coolant Temperature of 160°F. You need to take it on a nice long drive for it to properly Learn. I see your Learn Table is well populated at this point. You will need to continue to Transfer Learning To Base and smooth out the Base Fuel Table before you can dial in the lean spikes. Transfer Learning To Base with a smooth Base Fuel table may solve most of your cruising issues. I'll still adjust the Target A/F Ratio table. Those 15.5 spots will not be too friendly if you approach those while cruising.

    On a side note, the cold start looks to be much better.

  4. #24


    If the supplied coolant temperature sensor is bad, most have read high at lower temperatures and they read low at higher temperatures. Mine read about 30°F high when the engine was cold and about 30°F low at high temperatures. It would rarely indicate above 160°F with a 190°F thermostat, which meant that it wouldn't go into Learn mode. The replacement temperature sensor worked perfectly. If your CTS is bad you shouldn't try to tune around it - replace it and then tune. You may find at start with a good sensor, the cold start compensation will work well. Do a search on CTS problems and you'll find more than a few.

Page 3 of 3 FirstFirst 123

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