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Duratec rebuilder/tuner

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  • Duratec rebuilder/tuner

    I am looking for someone with experience in rebuilding a 2.0/2.3l Duratec in SoCal. I am having fits getting mine to run smoothly and have eliminated everything except a mechanical issue. Any help would be greatly appreciated.
    Wide-body Birkin, 2.3l Duratec

  • #2
    What kind of miles on it? Street or track days?

    Tell us more about the symptoms?


    • #3
      This is a newly built engine. It is installed in a new Birkin chassis. It is a 2.3l Ranger engine running Crower Stage 1 cams, stock pistons (9.7:1) and 48mm Jenvey ITBs. The ECU is a Typhoon 2 provided by Tom Carlin, the Birkin distributor. Tom provided a base map that has worked on a number of his other customers cars on first start. He has even taken back the ECU and it's harness and tested it on another car in his shop with no problems.

      When I start the engine, it will not attain anything like a stable idle. It runs quite rough with occasional backfiring. I am only able to sustain any run time by blipping the throttle between 1500-3000 rpm. I have verified the fixed timing of the engine several times; it is exactly correct. Van Nguyen stopped by the other day and worked with me for a couple of hours verifying that I had done this correctly. There is no evidence that the timing chain is slipping however, Tom Carlin and I are convinced, through a process of elimination, that this must be a mechanical issue. All we are left to conclude is that there may be a bent valve or two. I did a compression check yesterday on the cold engine without adding any oil to the combustion chambers and got 173, 170,180, 170. If the valves are dinged, it's not much (10 psi spread?) but it may be enough to keep it from running smoothly. If this were a conventional motor with carbs and a distributor, I would say that the ignition timing or the cam timing was off. That isn't possible with a Duratec if it's set up correctly. The software is spot on, the individual coils are new from Accel, the injectors are newly refurbished by RC Engineering.

      Tom has been incredibly patient on the phone and veery helpful throughout the build but we are both stumped at this point. I will probably pull the motor this week and remove the head for a closer inspection. I have built a number of engines over the years and am comfortable with the process which only adds to the frustration. I could really use a Duratec guru at this point.
      Wide-body Birkin, 2.3l Duratec


      • #4
        With compression like that, I doubt it is a bent valve or one that is not seating. When you checked the compression did you do it with the throttle wide open?

        You should be able to check the valve timing by using the stop pin and the cam timing plate.

        With backfiring it's usually either an ignition timing issue or a vacuum leak causing a lean miss. Based on it running at higher RPM I would check for the vacuum leak.

        If you can get it to run try to find the vacuum leak by spraying some carb cleaner around the TB mounting points or anyplace that might leak. Do you have a UNISYN or other way to balance the throttle bodies?

        Are all the butterflys opening fully? Closing almost fully. Generally they should be open just a bit when 'closed'.

        Post or send me some photos doug at tidsales dot com.
        Last edited by Doug Liedblad; November 6, 2016, 09:07 PM.


        • #5
          All four plugs were pulled for the impression check. The valve timing has been checked several times. It is spot on. The backfiring occurs in the course of "blipping" the throttle to keep it running (between 1000 and 3000 rpm). The intake manifold is sealed to the head with o-rings as are the ITBs to the manifold. A leak there is improbable. The butterflies are adjusted evenly against an .032" wire at the closed position. They operate smoothly to the full open position. The TPS has been calibrated to reflect that range of motion. The coils have been swapped across positions several times. The final fuel filter has been checked and is clean. There was an exhaust gasket leak (due to the type of gasket) but that has been corrected.

          These are early 48mm Jenvey ITBs. They have no air correction screw. They were meticulously cleaned. The shaft seals are excellent. The valve train was set up by Vellios Machine in Gardena at .008 and .010 (as called for by Crower). I am headed out to the car now to recheck the valve clearances. What am I missing?
          Wide-body Birkin, 2.3l Duratec


          • #6
            Have you checked the crank position sensor? Is it a stock one or aftermarket working off a toothed wheel on the front of the crankshaft? If so is the clearance correct? Cam sensor? I am more familiar with Zetecs that trigger off the flywheel. I don't remember where the Duratec has it's CPS.

            Have you hooked up a timing light to see if it is firing correctly when running?

            I presume new spark plugs? I have had them fail and do strange things.

            While you pulled the plugs for the compression check, did you hold the throttle wide open? It does make a difference.

            Are the injectors stock? Even though you had them serviced did you test them yourself? You should be able to see them spray as you look inside the throttle bodies with wide open throttle and cranking. DISCONNECT THE COILS first so it doesn't backfire and take your eyebrows off.

            Call me to discuss. 805-402-1225
            Last edited by Doug Liedblad; November 7, 2016, 09:33 AM.


            • #7
              New crank position sensor, correctly installed. New crank pulley cam position sensor works correctly. New plugs, correctly gapped. The injectors (26lb) are used but tested and cleaned by RC Engineering. I haven't verified the timing with a light.
              Wide-body Birkin, 2.3l Duratec


              • #8
                With good compression
                Good Spark
                Proper fuel mixture, not rich, not lean

                All at the correct times it WILL run properly.

                If you can get it to run in the 1000-3000 RPM range do that for a few minutes, shut it off and pull the plugs. What do they look like?

                Call me, I'll come down and take a look.



                • #9
                  I have decided to go ahead and pull the drivetrain out. I need to fix a couple of minor leaks (2" sump seam leak and the T-9 shifter rod/bellhousing leak) and revise the dipstick/sump seal. This will also give me a chance to recheck and reorganize the wiring passthrough at the top of the tunnel to absolutely eliminate any pinched wiring there. I may take the time to put a degree wheel on the crank and go through the crank/cam timing "old school". Yesterday, I even checked the spark plug/coil connections (perfect). Racking my brain to think of anything else.
                  Wide-body Birkin, 2.3l Duratec


                  • #10
                    Update - I pulled the engine and corrected the leaks. I replaced the fuel rail with a "single entry" one and installed a new fuel pressure regulator at the tank. This eliminated the return line from the engine. I replaced the Accel coils with new Ford units (no change). Now that this is a rolling chassis, I can't get it into a U-Haul 6x12 trailer. The rear track is 5"7" and the door width is 4'10".

                    The base map that I got from Tom Carlin is for a 2.0l with 42mm ITBs and 19# injectors while I have a 2.3l with 48mm ITBs and 26# injectors. Tom doesn't think that is a problem but I am thinking that the map may be the issue. The Typhoon software has a remarkable amount of adjustability. It clearly runs rich but if I input an "across the board" fuel reduction (by changing the baro settings), I can't get it to run. Tom has graciously offered to resolve all of this if I can get the car to Vail where we can readily swap components. I have access to a great open trailer but it's the wrong time of year for that to be a workable solution.
                    Wide-body Birkin, 2.3l Duratec


                    • #11
                      IT LIVES!!! Finally have it running well. I changed the injectors back to 19# ones and put in a fresh set of Motorcraft plugs. The missing link was that the butterflies were open too much at .032" at idle. Go figure. I set them to .003" and it started right up. As it warmed up, the idle settled down from 1800 to about 950 rpm. Once it was running 4 minutes, the O2 sensor closed loop kicked in and the ECU started adjusting things. Sweet.
                      Wide-body Birkin, 2.3l Duratec


                      • #12
                        Great news! Good job, maybe now we can finally go for a drive