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Thread: New Guy Questions

  1. #11
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    Quote Originally Posted by racindego View Post
    I'm not sure how much of the cranking is syncing.
    This is what you need to determine.

    I have read a little about System Logs to be able to watch this, but still have some things to learn.
    You don't need to record a System Log yet. A regular Datalog will provide the necessary data to determine this.

    I'm not sure yet how to do that or look for RPM Errors.
    Simply review the RPM channel of a short regular Datalog.

    Yes, wasted-spark, 60-2 crank trigger, and EFI Connection cam sync.
    I have the same Holley DIS ignition system (except for the EFI Connection cam sync unit,
    but my cam sync is still a single pulse), and my BBF engine starts a tad faster than yours.

    I have my cam & crank sensors powered from the ignition plug since that is what the directions state, and it was plug & play.
    With the minor wiring modification I outlined in that Link, the crank & cam sensor sub-harness still remains "plug & play".

    I do see the advantage of wiring the way you describe though. If I ever have a problem like described, that will be the first thing I check.
    The problem I described in that Link, still causes extended cranking times. Depending on the severity of the RPM Errors
    (sometimes they're so small the datalog won't display it), the engine will start & run, but it cranks longer than it should.
    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.

  2. #12

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    OK, so I have been working on this a little bit here & there (don't have near the time I wish I could spend on it), and I have the car running very well. I have the coolant temp enrichment tuned almost perfectly, so that that the CL comp stays within 2% or so all the way through warmup. I could still use a little tuning on after start enrichment, but I'm getting closer. It starts better, not as quick as I would like, but probably the best it will get.

    I still have a few questions that I haven't been able to figure out though.

    1. The prime feature seems to work well, especially cold. It is a problem when hot though. Too high and the car won't start. I had to find a happy medium, which for my car seems to be around 50%. It really does better with more when cold, but the help section suggested value of 200% definitely won't work when hot. This seems like a setting that should have a chart so that you can adjust the prime at different coolant temps. Am I missing something, or am I again just asking for too much?

    2. Kind of the same as above. I have been tuning the IAC hold & decay. I like the car to idle down quickly, but can't stand if it overshoots below running rpm, so I have spent some time here to get what I want. It seems that the the IAC hold position should be adjustable at different coolant temps. If you set it high enough to hold above idle when cold, it holds way too high when warm. I had to find a happy medium again and I'm around 37%. This seems like it could be better with more adjustability.

    3. Now that I have spent some time working on the coolant temp enrichment and gotten it very close, I find myself wondering why? Since the EFI compensates anyway, and getting this perfect hasn't changed how the car runs really at all (I didn't think it would). I have to wonder if this isn't just preparing for when a WBO2 sensor fails and I have to run the car in open loop? What else would the point be?

    4. This one is nit picky, I know. The exhaust still smells on my car. Not as bad as it did with the carb, but bad enough that my clothes stink after driving it. There is no visible exhaust like its running rich or anything, just still stinks like an old hot rod. Can I improve this? Can I lean out the mixture at idle to 14.5:1 or 15:1 and be safe? Should I put catalytic converters on the car (seriously)? Should I just stop being a girl about this?

    Thanks!
    Last edited by racindego; 10-28-2014 at 09:50 AM.

  3. #13
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    Quote Originally Posted by racindego View Post
    1. The prime feature seems to work well, especially cold. It is a problem when hot though. Too high and the car won't start. I had to find a happy medium, which for my car seems to be around 50%. It really does better with more when cold, but the help section suggested value of 200% definitely won't work when hot. This seems like a setting that should have a chart so that you can adjust the prime at different coolant temps. Am I missing something, or am I again just asking for too much?
    Yes, a temperature scale would be nice. However, good starting is still possible:
    http://forums.holley.com/showthread....6254#post36254 (Good Starting Advice Thread)

    2. Kind of the same as above. I have been tuning the IAC hold & decay. I like the car to idle down quickly, but can't stand if it overshoots below running rpm, so I have spent some time here to get what I want. It seems that the the IAC hold position should be adjustable at different coolant temps. If you set it high enough to hold above idle when cold, it holds way too high when warm. I had to find a happy medium again and I'm around 37%. This seems like it could be better with more adjustability.
    You shouldn't need a specific IAC Hold Position when the engine is cold, because the Target Idle Speed RPM is already increased during warmup. If it overshoots & idles below the target RPM, either the throttle blades aren't set right (idle speed screw), or the AFR (Fuel Table) isn't tuned right.
    http://forums.holley.com/showthread....neral-IAC-Info (IAC Information - Read "IAC NOTES")

    3. Now that I have spent some time working on the coolant temp enrichment and gotten it very close, I find myself wondering why? Since the EFI compensates anyway, and getting this perfect hasn't changed how the car runs really at all (I didn't think it would). I have to wonder if this isn't just preparing for when a WBO2 sensor fails and I have to run the car in open loop? What else would the point be?
    If the Coolant Temperature Enrichment isn't tuned, and you drive the vehicle during this cold period, the ECU needs to repeat the compensation amount every time you change TPS & MAP position. This repeat compensation takes time (albeit quick), and can cause a rough running engine until it warms up. If you cold start & let it idle until it's warm, then it's not such a big deal, because the ECU can remain in a steady compensation each step of the way.

    4. This one is nit picky, I know. The exhaust still smells on my car. Not as bad as it did with the carb, but bad enough that my clothes stink after driving it. There is no visible exhaust like its running rich or anything, just still stinks like an old hot rod. Can I improve this? Can I lean out the mixture at idle to 14.5:1 or 15:1 and be safe?
    Certain camshafts are worse than others. What's the timing advance at idle? 14.5-15:1 AFR at idle is fine if that's what the engine likes.
    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.

  4. #14

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    Quote Originally Posted by Danny Cabral View Post
    Yes, a temperature scale would be nice. However, good starting is still possible:
    http://forums.holley.com/showthread....6254#post36254 (Good Starting Advice Thread)
    I have been through that thread, thanks. I think I'm nitpicking again. My car starts way better than described in that thread. But I have a mechanical engineering degree. So besides being an annoying perfectionist, I'm also a compulsive tinkerer...I guess I can't help it. LOL

    Quote Originally Posted by Danny Cabral View Post
    You shouldn't need a specific IAC Hold Position when the engine is cold, because the Target Idle Speed RPM is already increased during warmup. If it overshoots & idles below the target RPM, either the throttle blades aren't set right (idle speed screw), or the AFR (Fuel Table) isn't tuned right.
    http://forums.holley.com/showthread....neral-IAC-Info (IAC Information - Read "IAC NOTES")
    Same as above. I have all of this very close already. I just don't find that I can make the ramp down completely consistent as the car warms up. The car is a stick, so if I pop it in neutral as I coast to a light, that's when I can notice it. Probably no one else but me would notice though.

    Quote Originally Posted by Danny Cabral View Post
    If the Coolant Temperature Enrichment isn't tuned, and you drive the vehicle during this cold period, the ECU needs to repeat the compensation amount every time you change TPS & MAP position. This repeat compensation takes time (albeit quick), and can cause a rough running engine until it warms up. If you cold start & let it idle until it's warm, then it's not such a big deal, because the ECU can remain in a steady compensation each step of the way.
    Understood. That does actually make me feel a little better about spending the time to get it right.

    Quote Originally Posted by Danny Cabral View Post
    Certain camshafts are worse than others. What's the timing advance at idle? 14.5-15:1 AFR at idle is fine if that's what the engine likes.
    Timing advance at idle is around 25 degrees. I took the map from the GM small cap HEI base calibration, though I'm running the Holley DIS. I don't have the cam card, but my car has a pretty choppy camshaft with what I assume is a narrow LSA. Probably not ideal for what I'm doing. But it's the cam that has been in the car forever. It's an old school solid lifter cam. Am I chasing my tail trying to get it to not stink me out?

  5. #15
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    Quote Originally Posted by racindego View Post
    I have been through that thread, thanks. I think I'm nitpicking again. My car starts way better than described in that thread. But I have a mechanical engineering degree. So besides being an annoying perfectionist, I'm also a compulsive tinkerer...I guess I can't help it. LOL
    You should be able to achieve good starting performance with the advice in that link. Tuning the starting performance is difficult because of all the starting related parameters (Fuel, Prime, IAC, Timing, etc.). You may also want to read Section 5.0 of the Step-By-Step Beginner's Tuning, in the Holley EFI software "Help" Section.

    The car is a stick, so if I pop it in neutral as I coast to a light, that's when I can notice it. Probably no one else but me would notice though.
    I would datalog & review this occurrence. Scrutinize the RPM, AFR & Timing. Overlay the datalog, and watch where this happens (on the Fuel & Timing Tables). Also, first tune the Fuel Table with the "Decel Fuel Cutoff" disabled (if it isn't already). It should only be used after the engine is tuned.

    Am I chasing my tail trying to get it to not stink me out?
    Certain camshaft grinds are inherently worse than others, due to their lobe separation angle, valve overlap, cam timing, duration, etc. What you're smelling isn't necessarily an excessively lean or rich condition. It's just the emissions byproduct of your engine's combustion. Idle timing advance, A/F ratio, sequential injection & injector end angle are contributing factors. Idle tuning will usually only slightly improve the exhaust rich/fuel smell, but not eliminate it (if it's camshaft related). This is where tuning the Injector End Angle toward a negative value can be very beneficial (and not just at idle). Also, is this a sequentially injected application?
    http://forums.holley.com/showthread....e-Tuning-Notes (Additional Information)
    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.

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