Results 1 to 8 of 8

Thread: Idle/RPM error only at operating temp.

  1. #1

    Default Idle/RPM error only at operating temp.

    Hello this is my first post and I'm seeking any ideas, advice, or other views on an issue that I have been wrestling with for a few days. First the engine is a GM 5.3 24x with a Terminator throttle body that has been in service for 3-4 years with no problems. HP ECU and newly updated V5 firmware. So the issue that has been occurring is at cold start. The engine runs/idles great until it reaches operating temp 180-190°F, then starts to get a condition that idles rough starts to pop crack even through throttle body also intermittent RPM error.

    So far these are the things I've tried so far as per tech support, cam/crank sensors, metered wires to both sensors with 12V at power & signal, and continuity to shielding & ground, checked for nick/bare spots, pulled injectors and cleaned, new fuel filters, new coil packs, disabled cam sensor and Closed Loop to disregard WBO2 have manual fan so electric is disabled as well, A/C IAC Kick off also. Even went through Inputs & Outputs with tech support all with no results, condition still remains. Any help would be greatly appreciated. Issue starts at around 660 sec area of attached datalog. Also Global File is attached, thanks in advance.
    HEFI Log 20190616-164527 4;58 pm.zip june15 5.3 terminator V5.zip

  2. #2
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    22,398

    Default

    Quote Originally Posted by Ryan77 View Post
    ...also intermittent RPM error.
    There's the problem. An EFI system can never have an RPM Error. It could be either sensor losing signal. If a regular datalog
    indicates an "RPM Error" when scrolling through the problem area, then it's time for a System Log to confirm which sensor flatlines.

    Record a System Log to verify crank & cam sensor signals. Check mark the "RPM", "Crank" & "Cam" channels. Look for a uniform,
    uninterrupted crank or cam sensor signal pattern. The crank or cam sensor signal should never flatline (no pulse) or indicate an
    RPM "Error" anywhere. Also, fully charge the battery and ensure the engine is cranking fast enough, at least 100+ RPM. Another
    common issue, is trying to analyze a compressed view of a long System Log. Zoom In for detail - click & hold at one point of the
    datalog, and drag & release to another point nearby. It's best to record short System Logs/Datalogs that capture the problem.
    http://forums.holley.com/showthread....s-amp-Datalogs (Datalog & System Log Information)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: Dominator MPFI & DIS, 100HP progressive dry direct-port NOS, A/C, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, 160A 3G alternator, Optima Red battery, 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

    Default

    I agree 100% with the RPM Error. I've taken a System Log that's where and have noticed cam signal drops. This is where I'm struggling and I've changed cam sensor and crank sensor. Crank signal looks good, but still drops in cam signal and have also confirmed wires are good to cam sensor. Tech support even had us disable the cam sensor to see if that made a difference, but no change, actually ran worse. What would be a suggestion, try another cam sensor? Or maybe something else to look at that could cause cam signal loss. The thing that puzzles me is that the only commonality is that it only happens at operating temp. Will also try another System Log, but it's says not responding every time I try to take a new System Log, since we updated to the V5 ECU firmware.

  4. #4
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    22,398

    Default

    Quote Originally Posted by Ryan77 View Post
    The thing that puzzles me is that the only commonality is that it only happens at operating temp.
    I'd confirm sensor air gaps. https://forums.holley.com/showthread...232#post216232 (Related Forum Thread)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: Dominator MPFI & DIS, 100HP progressive dry direct-port NOS, A/C, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, 160A 3G alternator, Optima Red battery, 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.

  5. #5

    Default

    Thanks for the suggestions. I'll try these as soon as I can. I was able to get System Log issue rectified, had to reflash ECU again. After reflashing again engine ran for 40 minutes without issue. All I had time to run, but has run for up to an hour before RPM signal loss in the past. Is it common to see air gap issues after getting up to operating temp, or after years of service?

  6. #6
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    22,398

    Default

    Quote Originally Posted by Ryan77 View Post
    Is it common to see air gap issues after getting up to operating temp, or after years of service?
    No, but if the sensors are good, the wiring is good, reluctors are good, Ignition Parameters are correct, then air gap needs to be checked.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: Dominator MPFI & DIS, 100HP progressive dry direct-port NOS, A/C, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, 160A 3G alternator, Optima Red battery, 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.

  7. #7

    Default

    Finally an update on RPM issues. I've taken more System Logs and after researching what the crank sequence should be, we've found that as engine approaches operating temp I start to see one signal drops out! So after switching to a GM crank sensor and triple checking that it's good, I decided to investigate the reluctor wheel (24x) and found one cracked tooth within a couple of teeth of signal that drops and air gap is .007" everyplace except at problem area it is .005"! I was wondering if this is too close and needs a shim as the link says .030" or slightly less. Also, what's the run-out tolerance if anyone happens to know, so when everything goes back together all tolerances will be correct. Thanks so much!!

  8. #8
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    22,398

    Default

    Quote Originally Posted by Ryan77 View Post
    Also, what's the run-out tolerance if anyone happens to know, so when everything goes back together all tolerances will be correct. Thanks so much!!
    There's some radial run-out information here: https://forums.holley.com/showthread...radial+run-out (Custom 60-2 Crank Trigger Kit)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: Dominator MPFI & DIS, 100HP progressive dry direct-port NOS, A/C, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, 160A 3G alternator, Optima Red battery, 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