FRPS and CPS Pinging Signals

Discussion in '2005+ Mustang GT 4.6L Tech' started by boostedtrauma, Jul 29, 2020.

  1. boostedtrauma

    boostedtrauma Junior Member

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    Following the Stroker/6060/TVS swap, I am having an issue with fuel rail pressure pinging between 0 and 39psi and cam position pinging between 0 degrees and 40 degrees.

    The wiring harness is unchanged from before the engine swap. Grounds over the passenger side headlight, passenger engine mount bracket, and driver side cylinder head to firewall have been inspected (hooked up, free of corrosion or visual imperfection).

    I put two new DW340 pumps in my GT500 dual pump assembly that I have ran since 2017 without issue. I am considering swapping the pumps back out to stock GT500 pumps to rule out a failing pump.

    So far, I have replaced the battery, alternator, and FRPS with no changes.

    I have probed the cam position sensors on the new engine and known good ones on the engine I pulled out. All read about 355 ohms, so I am assuming the CPS sensors themselves are good.

    I probed the GRY/RED signal return wire from each sensor (FRPS, CPS1, CPS2) to Fuse 58 using sewing needles and a multimeter and got 6.70 kohm. This value seems high, but is consistent for each sensor. This leads me to thinking I may have a bad connector/splice point.

    Looking into the wiring diagrams, I see reference to a splice point 102 where all of this comes together prior to the connectors. Do any of you know roughly where this point is? I wrapped my wiring harness with ELEVEN rolls of 3M electrical tape while the engine was out, so cutting into can hopefully be kept to a minimum.

    If not wiring, could a bad DW340 pump be causing this, as in the fuel pressure pinging is actual and the cams are "coughing" as a result? It doesn't have the diesel clack I've always associated with failing 3v phasers, and no codes, granted it has about 5 minutes of run time and one mile since first start.

    cam angle.JPG

    pressure drop short drive.JPG
     
  2. Midlife Crises

    Midlife Crises Member

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    If you chart the PIDs; fuel pump duty cycle, fuel pump voltage and fuel rail pressure and rpm while the engine is idling you can wiggle the connectors on the fuel pump controller, fuel hat and fuel rail. Any poor connection will show up on the data log. I think you have intermittent connections in your fuel pump or controller wiring. The contacts are easy to damage. I am running a pare of DW300s and they work very well.
     
  3. boostedtrauma

    boostedtrauma Junior Member

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    I primarily suspected fuel pump(s) as well since they're a new change, and I've logged duty cycle, RPM, fuel pump voltage, and battery voltage without finding any major abnormality.

    I hooked up a mechanical fuel pressure guage (cheapo from a box store) T'd into the fuel line just before the rail. It didn't show the wild variation I'm seeing in the logs. It stayed at 33ish PSI on the mechanical gauge.

    That puts me back towards an electrical issue, most likely in the GRY/RED circuit.
     
  4. boostedtrauma

    boostedtrauma Junior Member

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    Here is the most recent log showing actual voltage at fuel pump, pump voltage from table, duty cycle, and RPM, very short start and idle with mechanical fuel gauge hooked up.

    Let me know if you think it would be beneficial to pull up other logs and dig into other values.

    actual voltage.JPG

    duty cycle 6.JPG

    pump voltage from table 6.JPG

    RPM.JPG
     
  5. Midlife Crises

    Midlife Crises Member

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    Your fuel pump duty cycle and actual voltage tell me your fuel pumps are working. I would like to see the fuel rail pressure logged with them but I think in that last set of logs the pumps are doing what they are supposed to.
     
  6. boostedtrauma

    boostedtrauma Junior Member

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    Duty cycle stays pretty stable at ~0.21/42% and fuel rail pressure is pinging between nothing and 39psi at cold start idle. That's what's weird. Fuel pump voltage, flow rate, and duty cycle look good, but FRPS and cam position values are wack. They're pinging back and forth between maximum and minimum values. The only common ground I've found so far was, funny enough, a ground- the GRY/RED signal return wire that is used by quite a few things, namely both cam position sensors, the FRPS, and cylinder head temp. Cylinder head temp is reading fine, which has me confused. I don't have a high end multimeter or probing equipment/knowledge, but using the continuity function on the multimeter gave a signal when probing fuse slot 58 and each of the GRY/RED pins on each connector for the FRPS and CPSs.

    So I'm stuck scratching my head.

    Duty cycle and FRPS.JPG
     
  7. boostedtrauma

    boostedtrauma Junior Member

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    May also be worth noting that my AEM oil pressure gauge is T'd in with the factory oil sending unit by the oil filter. It is pinging out at 100psi on cold start with 5W-20 in case it is mechanical.

    Boundary oil pump, Saleen 302 rotating assembly, ARP hardware, Cushman cams degreed to 116.5* ICL with Trick Flow crank gears (so the phasers were locked out to degree then unlocked by the engine builder) and Comp 113 springs and retainers, and all new Ford timing components, solenoids, and CPSs. It was assembled by HESCO in Birmingham, AL.

    I ran these same cams with Comp 113 springs and retainers on the stock engine for about 9 months without issue. They're .490/.510 lift, 228/242 @ .050 duration, 116LSA, so nothing crazy enough to be causing major phaser issues on brand new Ford phasers with Comp baby springs.

    But I'm not really thinking it is mechanical, as fuel pressure with the mechanical gauge showed a steady-ish 33psi and I'm not hearing anything abnormal with the car running. If the 0 to 39psi pings were real, I'd think I'd have seen it with the mechanical gauge, and if the cam position sensors were reading a slap between 0 and 40 degrees, I'd assume it'd have the old diesel clack we're all familiar with.

    Then again, that mechanical gauge could have been bad, and the PID readings could be true. I don't know :(
     
  8. Midlife Crises

    Midlife Crises Member

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    Looking at my own data using the same fuel pumps you are using. Idling at 800 to 900 RPM my fuel pump duty cycle is les than 0.18. The PID labeled fuel rail pressure is pretty calm at 39 to 40 and the actual voltage at fuel pump is about 5 volts. The fuel rail pressure sensor also measures fuel temperature. Is that wack also? Are you sure both pumps are running?
     
  9. boostedtrauma

    boostedtrauma Junior Member

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    I think duty cycle drops down to high .1X or .20 once RPM drops. I'll have to go back and check the drive down the driveway and back log.

    Mine is running just under 6 volts actual at the pump at cold start (1200-1300).

    I haven't logged fuel temperature.

    Haven't verified that both pumps are running. Next step is likely to swap back to stock GT500 pumps and see what happens.
     
  10. Midlife Crises

    Midlife Crises Member

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    If you are running the GT500 pump setup that uses two fuel pump controllers just unplug one while idling with a datalog recording. Plug it back in after 15 or 20 seconds and unplug the other one. Simple, if one pump is not working the engine will die.
    Can’t think of any reason to log fuel temperature other than to see if the signal is screwed up like some of the others.
     
  11. boostedtrauma

    boostedtrauma Junior Member

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    I'm avoiding idle time until I break the engine in. I may just have to drive it like it is to seat the rings then go back to problem solving.
     
  12. RED09GT

    RED09GT Senior Member S197 Team Member

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    Did the cam cards call for them to be installed at that center line?
    With the VCT only able to retard the cams, 116.5° sounds excessive. Most aftermarket cams designed for VCT have an ICL much lower (91° for hot rods, 102° for most comp SPR grinds).
     
  13. JeremyH

    JeremyH 3V Fuel Guru S197 Team Member

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    Nice catch. Not completely following what he did. Said they were degreed and locked at 116.5 but then unlocked? Would be fine for a locked cam but not sure if he is retarding it further.

    I still use vct, my custom cams have a 110 icl and I retard a max of 9-10 degrees above 4500 rpm.
     
  14. boostedtrauma

    boostedtrauma Junior Member

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    Yes sir, they do.

    received_813199792409251.jpeg
     
  15. boostedtrauma

    boostedtrauma Junior Member

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    Hey Jeremy, engine builder was supposed to have locked the phasers with BBR lockouts, degreed to 116° ICL with Trick Flow crank gears (116.5° is as close as the gears got), then removed the lockouts to retain VCT.

    All new Ford timing components: phasers, chains, guides, tensioners.
     
  16. JeremyH

    JeremyH 3V Fuel Guru S197 Team Member

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    Gotcha, makes sense.
     
  17. RED09GT

    RED09GT Senior Member S197 Team Member

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    Very interesting, Bullet told me to install mine at 102-104 degrees if I was going to use the VCT. They stongly advised me not to use it and install them at the 110.5 degrees on the cam card.
    My cams have more lift so that may be why they talked me out of using the VCT.
    I installed them at 108.5 and I am still not happy with the response prior to boost, might not be a problem for you with the TVS.
     
  18. boostedtrauma

    boostedtrauma Junior Member

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    I ran these cams with Comp 113 springs and an M122 while SBE for several months and they were great even with a 3650, 3.31s, and 27.3" tire. City traffic wasn't a problem. The only time it was iffy was creeping through a parking deck. I'm really impressed with them. They're Cushman blower cams.

    I'm curious to see how they will be soon with the 3.800" stroke, 6060, 3.73s, and 26.7" tire.
     
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