Announcement

Collapse
No announcement yet.

Series IIA 109 Rough Idle Misfire Vacuum Leak Troubleshooting

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

  • #31
    I bet someone has a spare. I'll check tomorrow. If I do it's yours.
    ---------------------------------------------------
    '73 S3 88"
    '87 110 garden shed

    Comment


    • #32
      Ok, quick update. I was able to get a few different lengths of 10-32 machine screws from the hardware store to serve as the replacement idle speed screw. I reused a spring from an old idle mixture mixture screw for tension. This setup seems to work pretty well, and I ended up using the 3/4" screw with that spring.

      So, if only it was that easy. I warmed the truck up, set the timing to 15 degrees btdc, and started to tune the carb with a vacuum gauge. I started to notice that it seemed like I was chasing my tail. I would make an adjustment, let the truck idle, and notice that the idle speed was fluctuating quite a bit. I took a video for you all to check out.

      Also, to make things more interesting, my timing light/tach was inconsistent. I was not getting consistent strobing, or RPM measurement. ugh.


      During that process, there was a moment when the truck stalled out completely, and I hear a gnarly noise coming from the rear of the truck. Fuel pump? It sounded similar to the noise that I hear when I first flip on the ignition before starting the truck, almost like the pump is priming itself, however, that noise typically dissipates within a few moments. This noise was loud, and consistent until I turned the ignition off. I turned the ignition back on a few times to see if the noise would go away, and it did not. I let the truck sit for maybe 5 minutes, switched the ignition on, and the noise returned to normal. It's strong when first receiving power, but then dissipates to nothing within 5-10 seconds. Stupid question, but did the fuel pump overheat or something?

      So, I have no idea what the fuel pump setup is on this truck. Seems to be an upgraded electronic pump mounted somewhere in the rear of the truck.

      Oh wise Land Rover friends, teach me how to inspect and diagnose this fuel system to rule that out of the equation?

      Comment


      • #33
        If that strobe light pattern is what you see in real life, I would see why the ignition is that intermittent. I think others may have suggested switching the plug lead that you put the timing light on. Check all the cylinders and see if any behave differently. It could be any number of things from faulty parts to loose connections.

        Then see if you can find that rear fuel pump and put eyes on it. I don't have an electric pump, so my advice is pretty thin, but if it's making the noise you heard, then start there. Check for constant power, constant ground, cracks in the fuel hose, etc.

        Keep going, you'll get there soon.
        ---------------------------------------------------
        '73 S3 88"
        '87 110 garden shed

        Comment


        • #34
          I've got that same timing light. I like it. Like Rust said, if you aren't seeing the light, then I would think that cylinder is not firing, or is sparking to ground so the light isn't picking it up. But seems to be an electrical issue now.

          Fuel delivery at idle takes very little fuel. If the pump was that bad, the vehicle would not be able to rev or accelerate at all. I've only ever had two fuel pumps in my life that continued to run the vehicle that were bad. With a fuel pump it's usually all or nothing. One was in an old Montero that sat for a few years. After the motor rebuild, it started up and ran, but very poorly. I dropped the tank and pulled the pump. I dropped it in some water and it pumped fine! But on a hunch, I put my finger over the end and the pressure pushed water out the back seal of the pump. So it had an internal seal failure. The 2nd one was on a 2004 Titan. I was on the interstate when all of a sudden it would no longer maintain 70mph. I had to slow to 50mph, but made it home and drove it another 2 days, with very little acceleration possible. But that is extremely rare.

          However, if it's making a noise it never made, or is getting louder, it may warrant replacement.
          There is nothing more dangerous than those who seek to alter the will of men through force or deception rather than logic.

          Comment


          • #35
            Ok, didn’t have time to get her fired up tonight, but I was able to take some photos of the fuel setup.

            A part of me was concerned that the harbor freight timing light wasn’t up to the task. But, Jeff from Advanced Distributors has been encouraging me to ditch the Crane Cams electrics, and get back to points.

            Comment


            • #36
              That fluted thing looks like a inline filter, has it been changed/cleaned? The fuel pump has the wires running to it.
              gene
              1960 109 w/ 200TDI
              rebuild blog; http://poppageno.blogspot.com/

              You don't see faith healers working in hospitals for the same reason you don't see psychics winning the lottery.

              Comment


              • #37
                Looks like a little Facet pump, which is fine. Like Gene said, it wouldn't hurt to clean the fuel filter and go ahead and have the fuel system eliminated as the source of the problem.

                I ran the Pertronix electronic setup in my NADA with no problems at all. You can run points if you want, but they can be fiddly, but then again so can some electronic ignition conversions so I hear. Switching back to points would rule out a problem there as well, so may be worth it from a troubleshooting standpoint.
                There is nothing more dangerous than those who seek to alter the will of men through force or deception rather than logic.

                Comment


                • #38
                  Originally posted by 50 wulf View Post
                  I've got that same timing light. I like it. Like Rust said, if you aren't seeing the light, then I would think that cylinder is not firing, or is sparking to ground so the light isn't picking it up. But seems to be an electrical issue now.

                  Fuel delivery at idle takes very little fuel. If the pump was that bad, the vehicle would not be able to rev or accelerate at all. I've only ever had two fuel pumps in my life that continued to run the vehicle that were bad. With a fuel pump it's usually all or nothing.

                  However, if it's making a noise it never made, or is getting louder, it may warrant replacement.
                  Can you give me an example of a location in the engine bay that sparking to ground would occur that would result in the timing light not picking up on ignition? To me, that sounds like it would be sparking to ground at the dizzy, and not making it down the plug wire at all, is that correct?

                  Originally posted by loose gravel View Post
                  That fluted thing looks like a inline filter, has it been changed/cleaned? The fuel pump has the wires running to it.
                  I have not touched the fuel system since taking possession of the truck. Only added stabilizer when needed, and recently added a can of BG 44k to try and help with some of the carbon deposits I'm sure exist due to how rich the truck had been running the last 2 years.

                  Would this be the only filter in a system like this? There is no visible filter in the engine bay.

                  Comment


                  • #39
                    Another no cost thing is to run the engine in the dark and look for spark jump. Or just run your hands along the wires while it’s running. I may have mentioned before that no one with points carries an electronic ignition as back up.

                    Comment


                    • #40
                      Originally posted by 50 wulf View Post
                      Looks like a little Facet pump, which is fine. Like Gene said, it wouldn't hurt to clean the fuel filter and go ahead and have the fuel system eliminated as the source of the problem.

                      I ran the Pertronix electronic setup in my NADA with no problems at all. You can run points if you want, but they can be fiddly, but then again so can some electronic ignition conversions so I hear. Switching back to points would rule out a problem there as well, so may be worth it from a troubleshooting standpoint.
                      Good eye on the Facet pump. At least I know what I'm looking at now. I know a lot of people run the Pertronix setup on these trucks. I have yet to talk to someone that runs the Crane Cams setup, and has good things to say about it.

                      Originally posted by series guy View Post
                      Another no cost thing is to run the engine in the dark and look for spark jump. Or just run your hands along the wires while it’s running. I may have mentioned before that no one with points carries an electronic ignition as back up.
                      Is this your way of saying that this electronic ignition setup may not be as reliable as one would hope for? Made chuckle.

                      Comment


                      • #41
                        Originally posted by dbeard85 View Post

                        Would this be the only filter in a system like this? There is no visible filter in the engine bay.
                        You would have to follow the fuel line to determine if there are any PO installed filters inline. Does the fuel line go directly to the carb?

                        gene
                        1960 109 w/ 200TDI
                        rebuild blog; http://poppageno.blogspot.com/

                        You don't see faith healers working in hospitals for the same reason you don't see psychics winning the lottery.

                        Comment


                        • #42
                          Update!

                          Wanted to throw new plugs in, since I already fouled the ones I put in a week ago. Also decided to give the previous magnacore wires, and see if the timing light performed better.

                          While getting the truck up to temp, I rested my hand on the intake, and the engine performance dramatically increased. I took a video to share. Am I discovering a vacuum leak somewhere on the manifold assembly that carb cleaner didn’t detect?


                          Comment


                          • #43
                            I think we have a vacuum leak! I didn't need to see whole video. You now know that at the very least you need to look at the gasket between the head and intake manifold and/or the gasket(s) under the carb. Cheap money and quick to replace for both. Also possible that they just loosened up a bit too much, which is an even easier fix.

                            After that, the fun continues.
                            ---------------------------------------------------
                            '73 S3 88"
                            '87 110 garden shed

                            Comment


                            • #44
                              Alright, attempted to play around with tightening some things last night to see if it could get any improvement, but no dice. Vacuum dramatically improves as soon as I put pressure on the intake elbow. I believe new gaskets are arriving on Saturday. Would it be helpful to apply a gasket sealant in addition to the metal/paper gaskets to aid in sealing up things nicely?

                              Comment


                              • #45
                                Dave... try taking the steel locating sleave out of the manifold under the carb...maybe the grove in the carb was not machined to the right depth for the sleave collar and letting it rock a little bit...also I coat my gaskets with a little never seez...they don't get brittle from the heat over time. LC PS r u going to Neil's tomorrow...say hello to all for me...miss the crew

                                Comment

                                Working...
                                X