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Thread: C950 22S issues

  1. #1
    exocaged Guest

    Default C950 22S issues

    its the 22s model

    I just cant get the thing tuned right. Have had it on for 6 or so years and although it has been close, it has never been right.

    Cam specs: Its a Speed Pro roller camshaft. pt# CS195R

    2000-5500 rpm range
    289 intake/ 299 exhaust adv. duration,
    duration @ .050 of 212 intake and 222 exhaust,
    Valve lift of .493 intake and .510 exhaust,
    Lobe C/L is 112

    the rest:
    Full roller rockers
    AFR 185 58CC heads
    stroked to 408 with 27.5CC dished pistons for pump gas

    This is an off road play truck, I rock crawl and sometimes play hard with it. its on 46" tires with a full manual C-6 tranny with a 2200 stall B&M converter. Axles have 4:88 gears and I also have a 4 to 1 Transfer case. Gearing is fine as it rarely ever gets put in 1 to 1 or put on pavement.

    to make it run descent I have to force it to run rich according to the O2 reading. The 347 ford base map wont run it ( yes I switched it to TBI ) I have to set the idle values to 25-26 to get a smooth/usable idle. The TBI fuel pressure is 24psi. I have never been able to get it lower for some reason. The return is 3/8 and its a nice straight shot to the cell with not hard turns or kinks. The exhaust is pace setter shorty headers into a single 3" pipe.

    if anyone can help me I would greatly appreciate it.


    Thanks
    Joe

  2. #2
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    Quote Originally Posted by exocaged View Post
    To make it run decent, I have to force it to run rich according to the O2 reading.
    The TBI fuel pressure is 24psi. I have never been able to get it lower for some reason. Thanks Joe
    Specifically, are you having idle problems?
    Have you integrated a wideband O2 sensor (feedback to ECU)?
    What exactly happens when attempting to lower fuel pressure?
    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
    exocaged Guest

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    i can make it idle just fine. I just have to force it to run rich according to the O2 reading. If I lower the value down to let the O2 do its thing, it starts surging. Even with a flat area surrounding the idle point. I have tried to adjust how fast it adjusts itself too with no good results. When I attempt to lower the pressure it just does not go down. just stays where it is, has been at 24psi since day one, no up or down at all. No i do not have the wideband O2 sensor. I feel it should work better as it is.

  4. #4
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    Quote Originally Posted by exocaged View Post
    I can make it idle just fine. I just have to force it to run rich according to the O2 reading. If I lower the value down to let the O2 do its thing, it starts surging. Even with a flat area surrounding the idle point.
    What are your O2 Compensation Limits (%)? Seems like your target O2 voltages are fighting your Fuel Map idle values. The Fuel Map values should not be flat in the idle area. It should be arranged (tuned) to manipulate the surrounding idle RPM & kPa cells to divert the highlighted cell toward the center target idle cell. I can explain further if you'd like. Conversely, the timing map should be flat in the idle area. How much timing advance are you using in the idle area?


    I have tried to adjust how fast it adjusts itself too with no good results. When I attempt to lower the pressure it just does not go down. just stays where it is, has been at 24psi since day one, no up or down at all.
    The fuel pressure regulator should be sensitive to adjustment with a 5/32" allen wrench. I would disassemble the fuel pressure regulator and inspect for damage. Use this regulator kit to service it: http://www.holley.com/512-1.asp


    No, I do not have the wideband O2 sensor. I feel it should work better as it is.
    Your C950 EFI system will not function better with a narrowband O2 sensor.
    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
    exocaged Guest

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    By better, I meant better then what it is. I have read that the wideband is better then what I have. I'll adjust the fuel map this evening to get closer to what you are saying. I tried years ago to adjust the pressure like you describe. Nothing changed the pressure and since it was new I really didn't want to mess anything up so as I counted the turns I put it back where it was.

    My O2 compensation limits are at 20%.

    My timing at idle is about 30 degrees. It get rough and erratic when I drop it much lower. Starting timing is 18 degrees. Starts fine.

    Is there a way for me to simply post the maps and other info on here?

  6. #6
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    Are you using a fuel pressure gauge when attempting to adjust fuel pressure?
    Change all your O2 compensation values to 25%.
    Is the engine ignition timing synchronized with the ECU timing?
    Idle timing is synced by turning distributor and higher RPM are synced with "ignition propagation delay".
    Which electronic distributor are you using? "Timing advance while cranking" is only enabled with inductive or Hall-Effect types of RPM signals.
    You can "insert images" that are hosted from another site, such as Photobucket.com.
    Last edited by Danny Cabral; 05-02-2010 at 01:54 PM.
    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
    exocaged Guest

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    I set the ECM to 20 degrees and check with a light and it's right. I have TFI Ford distributor. I have a fuel pressure gauge on the TBI that seems to be accurate. I know I can change the timing advance when cranking and it will change the way it starts. So it does something.
    I'll do the 25% thing and try that.

  8. #8
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    Quote Originally Posted by exocaged View Post
    I set the ECM to 20 degrees and check with a light and it's right. I have TFI Ford distributor.
    Why is your ignition reference set to 20? Ford TFI is supposed to be set at 10° (it's not optional; read page 77 of C950 manual). With HEI or TFI, the timing during cranking will be the module's base timing below 400 RPM; you aren't changing anything. You need to set the Ignition Reference to 10° and re-sync the initial timing by turning the distributor. Then, synchronize the timing at 3000-4000 RPM using the Ignition Propagation Delay. The C950 really needs a wideband O2 sensor to function properly. It's not my opinion, it's fact. I highly suggest Holley's own 534-197 WBO2 sensor kit; it's "plug & play" with the C950 harness:
    http://www.race-mart.com/Holley_Perf...L-534-197.html


    TIP: There is an easier way to synchronize the ignition timing, however you must have your Spark Map saved/copied somewhere. You can simulate locked-out timing advance, by entering the same value in every cell of the Spark Map. I like to use 30°. You can use the "Cell Action" function to automatically enter 30° in the entire map, so you don't have to do it manually. Also, temporarily uncheck the "Enable Idle Spark Control" box in the "Spark" drop down menu, so the idle timing doesn't rapidly fluctuate. This is not real time editable and requires a restart. Enable it after you're finished with the ignition timing. This is easier, since you won't need to look at the laptop computer while synchronizing the idle timing and the Propagation Delay.

    Without disconnecting anything and using a timing light, start the warm engine and turn the distributor to synchronize the engine's initial timing with the idle timing on the laptop computer. When the initial timing (idle) is synchronized, lock down the distributor's adjustment bolt and never touch it again (for this purpose). After synchronizing the initial timing (distributor hold-down bolt tight), ALL timing adjustments/tuning is done on the laptop computer.

    Then use the "Ignition Propagation Delay" function to synchronize the timing advance at the higher RPM (3000-4000 RPM). It's all 30°, so you can momentarily rev the engine, and watch for the timing to drift away from 30° to synchronize the Propagation Delay. Adjust the Propagation Delay until the ECU maintains itself at 30°. If at 3000 RPM, the actual timing you see with a timing light is less than what's on the Timing Table (software), increase the Propagation Delay until it matches. If at 3000 RPM, the timing light shows more than the Timing Table (software), decrease the Propagation Delay until it matches. You can adjust it while the engine is running. It is real time adjustable (click enter after each numerical change). Some applications use a setting well above the default value of 248 usec. Believe your timing light above all else!

    Think of the "Ignition Reference" as just a software setting; no adjustment or tuning required. With a GM HEI or Ford TFI, simply set it to 10 (it's not your idle timing) and forget about it. Conversely, the Ignition Propagation Delay needs to be adjusted to synchronize the timing at higher RPM.
    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.

  9. #9
    exocaged Guest

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    It's not set to 20. I set the ECM to 20 to see if it matched with the spark. It did.

    $330.00 to make an efi system work? That's bs. If it must have the WB then it should have been included in the kit.

  10. #10
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    Quote Originally Posted by exocaged View Post
    $330.00 to make an EFI system work? That's BS. If it must have the WB then it should have been included in the kit.
    Holley didn't manufacture its own WBO2 kit until many years after the C950 inception. However, the version 3.x firmware has always been capable of integrating any aftermarket WBO2 kit to the ECU and the C950 manual has clear instructions on this. Incidentally, the new Holley EFI systems do in fact, include a proprietary wideband O2 sensor (integrated WBO2 controller).

    Again, it's not that the C950 absolutely needs a WBO2 sensor to function properly BUT you'll never get optimum performance without it. It's like saying, your vehicle can run with a carburetor, but EFI is an upgrade you've just got to have. If you upgrade your system with the aforementioned WBO2 kit ($290 @ Race-Mart), email me a copy of your engine file and I'll take a look at. I'm very proficient at tuning the C950.
    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.

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