Page 3 of 3 FirstFirst 123
Results 21 to 26 of 26

Thread: ZZ502 '68 Camaro fouling plugs?

  1. #21

    Default

    Highly doubt that it's a decent sized cam. 80s around 800-900 RPM if I recall? Sounds like I need to pull more? LOL.

  2. #22
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    28,004

    Default

    80 kPa idle is wrong. The MAP kPa is high because it's idling poorly (something is wrong).
    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. #23

    Default

    Quote Originally Posted by Pearl68 View Post
    Highly doubt that it's a decent sized cam. 80s around 800-900 RPM if I recall? Sounds like I need to pull more? LOL.
    80 kPa is race car territory. We're talking 30-40 degrees of overlap on the cam and 1100 RPM minimum idle. It's entirely likely that your plugs were so fouled, several cylinders were not firing...at all. This would explain the 80 kPa, as well as the false lean condition that caused the Learn Table to have those high numbers. I'd be happy to help you tune this engine. I had a 502 in my '70 GTO when I first built it in the early 2000s. Andrew
    Instagram: @projectgattago
    Offering remote Holley EFI tuning.
    I deliver what EFI promises.
    Please get in touch if I can be of service.

  4. #24

    Default

    @Andrewb70: PM sent to your inbox.

  5. #25

    Default

    A ZZ502 is a very mild combo with great vacuum at idle. They should idle around 50 kPa, if not a little lower unless the cam has been changed to something fairly wild. A stone stock ZZ502 typically won't wake up a sleeping baby. If you can't get one of those to run with a Sniper then you have a major mechanical problem somewhere. Exhaust leak, vacuum leak, bum cylinder, etc.

  6. #26

    Default

    It has to be something simple. It was running decently well when I pulled the carb off last month. Just tracking bugs.

    Thank you all! Latest datalogs and Config Files idles now no throttle. It certainly needs a touch more, but looks way better? Mr. Andrew & I will start dialing it in shortly.
    Attached Files Attached Files

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