Announcement

Collapse
No announcement yet.

Hard starting kick backs and back fires

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Originally posted by 77 C3 Corvette View Post
    I have pulled # 1 spark plug put my finger over the hole had my girlfriend bump the starter until air starts coming out of that hole the front drivers side cylinder if you are looking at engine from outside lined up the mark on the harmonic balancer the big 8" round thing at the end of the crank shaft to the 0 degree mark on the timing tab at least 25 times
    Just tot Clarify, After you found 0 degree mark, did you rotate the engine counter clockwise to the 12 degree mark and then install distributor pointed at # 1 with the small tooth just entering the pickup?

    Comment


    • #17
      Yes I did it will not run at 12 degrees before tdc it would fire at 0 degrees tdc then unlock timing on tablet but it ran rough back firing it's been getting progressively worse that what makes me think the magnetic pick up coil is going bad in the distributor I have removed the distributor wiring harness and ECU will ship it back to Edelbrock for them to bench test it I couldn't even get it to fire this morning

      Comment


      • #18
        [QUOTE=77 C3 Corvette;n36875]I have pulled # 1 spark plug put my finger over the hole had my girlfriend bump the starter until air starts coming out of that hole the front drivers side cylinder if you are looking at engine from outside lined up the mark on the harmonic balancer the big 8" round thing at the end of the crank shaft to the 0 degree mark on the timing tab at least 25 times now I'm taking it apart and sending the distributor Wiring harness tablet and ECU back to Edelbrock to be bench tested acts like the pick up coil in the distributor has failed it is progressively getting worse the company who built this custom crate engine is also in contact with Edelbrock [/QUOT

        Something to keep in mind : The harmonic balancer is keyed in position to the crank shaft. The crank shaft determines determines where TDC occurs since the rods are are slaves to the offset ground crank journals. Therefore, # 1 piston TDC will always occur at the same place relative to the balancer location. This does not however mean that your distributor rotor is properly phased to your TDC since the distributor rotation occurs from your camshaft. Technically, you have not yet determined that your timing assembly gears are correctly installed 6 o clock to 12 o clock respectively. You have only felt a piff of air on #1 and then rotated your crank to the next time 12 degrees BTDC occurs on the balancer. You really need to remove the timing cover and witness your timing gear relationship if all other components pass their tests. I was stuck on this very same issue for a month and finally bit the bullet, removed my timing chain cover, and found the smoking gun.
        Last edited by a990hemi; 07-23-2020, 10:02 AM.

        Comment


        • #19
          Update Edelbrock sent all items back after testing quote from tester (parts tested OK;REFLASH FIRMWARE & CALIBRATION) reinstalled all parts set distributor in at 12 degrees BTDC engine fired right up set timing with timing light unlock timing on tablet NO BACK FIRES OR STARTER KICKBACKS ??? no mention of any parts changed out timing chain and gears were not off as I have stated only thing I can figure out is the pickup coil was going bad it does idle rough when it gets below 1000 rpm tried to set idle at 850 had to go up to 975 still kinda rough shut it down and fired it right back up with no problem need to fine tune it

          Comment


          • #20
            Originally posted by 77 C3 Corvette View Post
            Update Edelbrock sent all items back after testing quote from tester (parts tested OK;REFLASH FIRMWARE & CALIBRATION) reinstalled all parts set distributor in at 12 degrees BTDC engine fired right up set timing with timing light unlock timing on tablet NO BACK FIRES OR STARTER KICKBACKS ??? no mention of any parts changed out timing chain and gears were not off as I have stated only thing I can figure out is the pickup coil was going bad it does idle rough when it gets below 1000 rpm tried to set idle at 850 had to go up to 975 still kinda rough shut it down and fired it right back up with no problem need to fine tune it
            Found during testing --- Base Timing check was left in the " Lock " timing mode.

            Once all was reset, was working as designed.

            Comment


            • #21
              Welcome to my nightmare as stated before reinstalled all parts set distributor in at 12 degrees BTDC engine fired right up tried to set idle if idle gets below 1000 rpm engine runs rough shaking like its miss firing. Called it a night. Went out the next morning fired Corvette up pulled it out of my shop drove it for 2 miles first mile and half car ran fine had it up to 70 mph on the highway turned onto my road stopped at the stop sign engine died had a hard time restarting it last half mile engine sputtering shaking couldn't get more that 30mph died twice. Changed matrix map to 5023 turned down fuel pressure to 45psi still sitting in the driveway im at a loss I've done everything tech support has asked changed out fuel pump installed relay on fuel pump toggle switch on pink and black wire have it going straight from positive side of battery before anyone asks battery is brand new changed out coil to msd 8222 starter is high torque starter from summit racing im over throwing money at this thing

              Comment


              • #22
                2700 Cast im still trying to understand what you wrote (Found during testing --- Base Timing check was left in the " Lock " timing mode.
                Once all was reset, was working as designed.) If you follow your instructions start engine set base timing with timing light at 12 degrees BTDC press unlock timing on tablet am I missing something? Return sheet makes no mention of that sounds like when I got told you can't run the MSD Street fire coil even though its on the approved list of coils on Edelbrocks instalation instructions. Or how when I called about my part's I was told my stuff was sitting in the middle of a table full of stuff to be tested and the tech wast driving the test vehicle with another customer's parts (My parts showed up 2 days later on second day freight ) I have the feeling some one is talking out of both sides of thier neck
                You do not have permission to view this gallery.
                This gallery has 1 photos.

                Comment


                • #23
                  When you called my Electronics tech was driving a car & not available.
                  Sometime after that he tested your parts and sent them out the same way you sent them.

                  After your earlier post you stated the "Pick up coil must be bad?"

                  So I reviewed his notes, to find the " Fix".
                  He found the timing stuck on 12degrees.

                  After he unlocked the timing & re flashed/reloaded MAP he confirmed was OK, by running it in our Test vehicle.

                  Note: With Covid our response times have been longer, due to Furloughs/short staffed.

                  Hope this info puts you at ease.

                  Comment


                  • #24
                    No that info doesn't put me at ease. I'll tell you what else it doesn't do it won't make this engine run either

                    Comment


                    • #25
                      The system ran on their test vehicle with no issues so to me that rules out any issues with the PF4 system. Their tech said it was stuck on 12 degree when they checked the settings after installing your system on their vehicle which tells me you didn't "unlock" it.

                      engine problems on your end not withstanding like timing chain out of time, slipped, etc.



                      Comment

                      Working...
                      X