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Matt Brandsema

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  • in reply to: Random Misfire on 4.3 Vortec Engine, GMC #883587
    Matt BrandsemaMatt Brandsema
    Participant

      Update. The morning after I cleaned the contacts, it was back to misfiring. When I went to install a new cap and rotor, there was a TSB inside the cap box that said the 4.3 Vortec engines have two vents located inside the distributor that clog up/have insufficient flow, and allow moisture to build up inside the cap and this corrodes the contacts and causes misfiring. When I replaced the cap and rotor I sprayed brake clean down the 2 vent holes and then blasted them out with compressed air and the truck has been running like a champ ever since!

      in reply to: Random Misfire on 4.3 Vortec Engine, GMC #883515
      Matt BrandsemaMatt Brandsema
      Participant

        Ok! I replaced the coil and I was still getting arcing. I thought to myself that somehow the path through the cables to ground is an easier one than the path through the spark plug gap. So SOMETHING in that circuit has excessive impedance. I removed the distributor cap and cleaned the contacts with sand paper (I had looked at the cap before but I don’t work too much on cars with distributors so I didn’t know what to look for). After cleaning, it put it all back together and no more misfires! I took it for a very long drive and looked at the codes in the computer, there is a PENDING code for cylinder #1 misfire, but It isn’t a hard code yet (it could be I didn’t clean the contact as good). I don’t FEEL any misfires anymore so for the most part, that seemed to have fixed the problem. I am going to replace the cap and rotor with quality parts and hopefully call this one done!

        I had disregarded the cap and rotor because the previous owner that I bought the truck from (I just bought this truck a few weeks ago) said he replaced the cap and rotor about a year ago.

        Thanks so much for all the help with everything!

        EDIT:

        I forgot to mention that if I put my fingers on the ignition cable, I get a little bit of arcing to my fingers (cant feel it so don’t worry). I have heard that once breakdown occurs through the wires, they are shot. Is this true?

        in reply to: Random Misfire on 4.3 Vortec Engine, GMC #883484
        Matt BrandsemaMatt Brandsema
        Participant

          A HA! I got it! After measuring all the waveforms from the crank (which looked a lot better, I think I had a bad connection last time) and the ignition coil, I decided to simply turn off the lights and see if I can see spark arcing where it isn’t supposed to. And Low and behold, I am getting arcing between the coil and the laminated core around the coil, as well as the main ignition wire going from the plug to the distributor (which is a new wire!).

          I removed the coil and gave it a wash and used contact cleaner on the connections, as well as cleaned up where it bolts to the engine to see if maybe there was a bad connection or something driving up the voltage. After doing all that, I am still getting arcing, but mainly on the wire going to the distributor. I wonder if I should just replace the coil. Tomorrow I am going to redo the resistance checks (which it passed btw), but both when it is cold and when it is hot. I would bet that as the coil gets hotter, it will fail the resistance spec tests.

          in reply to: Random Misfire on 4.3 Vortec Engine, GMC #883451
          Matt BrandsemaMatt Brandsema
          Participant

            Wife’s car broke down yesterday so I had to fix that. Consequently I only had time yesterday to do the spark plugs on the truck. Some of them had a bit of blackish residue, and one had a bit of oil on it, but for the most part, they seemed good. I am not an expert on spark plug analysis. I will try to attach a pic later.

            Anyway, during the spark plug changing I pulled the fuel pump fuse and did some compression tests. I noticed that when I started it up after replacing the plugs, there was a loud *tick tick tick!* in the top end that wasn’t there when I pulled the truck into the shop. It sounded like it was coming from under the intake in the back (where the spider assembly is). After 5 or so minutes it went away. Don’t know what to make of it. Air in the lines from pulling the fuel pump fuse?? Will try to look at the waveforms today.

            in reply to: Random Misfire on 4.3 Vortec Engine, GMC #883437
            Matt BrandsemaMatt Brandsema
            Participant

              I will do that! It might only have 2 channels so I might have to do signal+Power and then signal +ground.

              I was probing at the PCM, not directly on the sensor

              in reply to: Random Misfire on 4.3 Vortec Engine, GMC #883427
              Matt BrandsemaMatt Brandsema
              Participant

                My crank sensor is 3 wire. Which I think should be a hall effect, right? My signal does not look the same as yours.

                in reply to: Random Misfire on 4.3 Vortec Engine, GMC #883423
                Matt BrandsemaMatt Brandsema
                Participant

                  I’ll replace the plugs, it is never a bad thing to do. I will also test spark. Recall I DID do a resistance check on the coil. There were actually 3 resistance checks in the service manual, and it passed all of them.

                  I work in a laboratory and I was able to bring home a lab oscilloscope to look at the sensor waveforms. The only one I have looked at thus far has been the crank sensor. I thought maybe the signal would periodically go bad and cause a misfire, but it seemed to be good. One thing that was weird is that it wasn’t a true square wave. It looked funny, like a decaying voltage at the top and bottom of each square. (See attached image!)

                  Today I drove it and I definitely could feel the misfires when I was driving it. It has just been so long since I drove it any real distance that I didn’t remember correctly. I already put one bottle of injector cleaner in it, but from what I hear, the stuff you buy off the shelf in an autoparts store generally isn’t strong enough to do much good. Maybe I need multiple bottles over many tanks as you suggest.. I also forgot to test at WOT.

                  in reply to: Random Misfire on 4.3 Vortec Engine, GMC #883406
                  Matt BrandsemaMatt Brandsema
                  Participant

                    Thanks for the reply!

                    It is difficult for me to feel the misfires when I am cruising / at higher RPMs. I mainly just go by sound at that point.

                    Today I unplugged the MAF sensor and the misfires seemed to remain the same, so that rules that out.

                    I think next I will pull the distributor and take a look. I feel as though I have ruled everything else out at this point. However I have never replaced the spark plugs. But I really do not think it is likely that enough spark plugs went to cause a random misfire. I also don’t have a way to test the ignition control module next to the coil.

                    There is also that slightly low fuel pressure…. I am trying to avoid replacing the spider injector assembly, but at this point I am running out of things to test. The pressure bleeds off very very slowly when I shut it off. Don’t know if this is a valve in the spider injector assembly, or the one way valve in the tank.

                    in reply to: Random Misfire on 4.3 Vortec Engine, GMC #883385
                    Matt BrandsemaMatt Brandsema
                    Participant

                      I believe if memory serves, the ignition advance was about 20 or so degrees. Definitely no less than 15.

                      I was going to pop off the distributor and then I realized that a worn gear doesn’t really fit with it getting much worse as the engine is hot. Here are a few more things I did.

                      1. Compression test of 3 more cylinders, all very good.
                      2. Removed EGR valve and plugged up vacuum port to see if the car ran better. It didn’t. This rules out the EGR valve as well as exhaust back pressure issues (Since the exhaust side of the EGR was just venting out).
                      3. This one is REALLY interesting. I looked at the MAF sensor data and every time there was a misfire, the MAF reading spiked upwards. I don’t know if the misfire is because of this spike, or the spike is because of the misfire.
                      4. Cleaned MAF, no change.

                      I think maybe it might be the MAF?? The one on there is very cheap and looks old, but I don’t know for sure…

                      EDIT:

                      Also, the fuel pressure WILL bleed down if I leave it on there for very long. But it hasn’t ever bled down below 40 PSI. Don’t know if this is because of the valve in the tank, or a spider injector leak problem.

                      in reply to: P0401 code that will not go away! (03 Honda Civic) #871351
                      Matt BrandsemaMatt Brandsema
                      Participant

                        Can’t be a bad sensor because all of the electronics came with the new EGR solenoid, as I think it is all built into one assembly (The valve has like 5 or 6 pins on it).

                        My EGR solenoid is electronic, not vacuum controlled.

                        I think what I will do is energize the solenoid at idle and see if I get a change in RPM.

                        in reply to: P0401 code that will not go away! (03 Honda Civic) #871330
                        Matt BrandsemaMatt Brandsema
                        Participant

                          [quote=”nightflyr” post=178699]Just a thought …
                          Did you inspect the EGR tube for damage or cracks?
                          Is it seated correctly in to the EGR valve?
                          Is the bolt holding the tube threaded correctly.?[/quote]

                          So that’s the thing, I do not think this EGR valve has any kind of tubes. Here is a picture of it.

                          The EGR valve bolts directly to a casting on the side of the head. In the casting there are two internal passage ways that go into the head. The passage ways are pretty large, and when I had the EGR valve off, it didn’t seem like they were gunked up at all. But maybe what I need to do is remove this casting from the head. That is a lot of work though and I would like to avoid doing work if I don’t need to.

                          Here is a picture of the side of the head with the casting removed that I found online. Here you can see some of the internal passage ways. The one big square one is for coolant I believe, and the two flatter ones are for the EGR.

                          Here is a picture from alldata. You can see the EGR bolted to the casting I was talking about (which is labeled as “water passage”).

                          in reply to: P0401 code that will not go away! (03 Honda Civic) #871327
                          Matt BrandsemaMatt Brandsema
                          Participant

                            I finally got around to the shop today. I hooked up my scan tool and looked at the data from the MAP sensor, and it seemed to make sense, but I don’t know much experience looking at MAP sensor data to compare to.

                            I hooked up a vacuum gauge and measured the vacuum at idle. It was about 18 inHg. I slowly revved it up and the vacuum went up to like 25. When I let it go back to idle the vacuum was at 22 inHg. So I do not think I have any kind of vacuum leak, especially one that would cause a code to be thrown.

                            I already replaced the EGR valve and it didn’t fix the problem. I am at a loss!

                            EDIT:
                            I am starting to think that maybe it is something crazy like, chips from the machine shop stuck in the EGR passageways in the head. I feel like the EGR system is simple, and I have checked everything except for these internal passage ways.

                            in reply to: Honda Civic Head Bolts Popping While torquing #864557
                            Matt BrandsemaMatt Brandsema
                            Participant

                              [quote=”nightflyr” post=171941]Not sure if you mentioned it or not.
                              Have you had the head checked for warping and or damage by a machine shop?
                              Has the block been check?[/quote]

                              Yes I did. No warpage or cracks and it was machined.

                              in reply to: Honda Civic Head Bolts Popping While torquing #864554
                              Matt BrandsemaMatt Brandsema
                              Participant

                                Okay I now have a definitive answer. I put the timing belt on and then did a leak down test. Cylinder numbers 1 and 4 (the two end cylinders) had AWESOME leakage numbers. Less than 10%. However cylinders number 2 and 3 (the two center ones) were leaking into each other. I could feel the air coming out of the opposite sparkplug hole when I did the leak down test.

                                So now I am going to pull the head again (luckily it isn’t much work), buy new bolts and gasket FROM HONDA, and try again.

                                in reply to: Honda Civic Head Bolts Popping While torquing #864488
                                Matt BrandsemaMatt Brandsema
                                Participant

                                  [quote=”nightflyr” post=171872]Interesting…
                                  Did you clean out the threaded areas of the block where the head bolts mate to?[/quote]

                                  Yes I sprayed them out with compressed air until nothing was coming out.

                                  This might sound strange but I noticed the same physical mechanism for “popping” also occurs when turning a sharpie marker in it’s cap (okay bear with me here). If I try to turn the cap slowly, I get popping while turning. However if I turn fast, the popping is less (same for headbolts). As an experiment, I lubed up the sharpie cap with oil to see if the popping would diminish at all. The oil did not help at ALL. Not one iota. Which means the popping isn’t really caused by lubrication issues, but rather the resistance to motion from the two parts of the pen turning in one another as the pen is slightly tapered.

                                  This leads me to believe that the issue here with the head bolts may be the actual bolts themselves. They are new ,cost me 50.00 bucks, but they were made in china and not from Honda. If the bolts were made with sloppy tolerances or with a worn out machine, they could be slightly larger than OEM ones or have a slight taper to them and cause excess resistance while spinning in the threads.

                                  Anyway this is all just me guessing. To test this hypothesis I could go buy new head bolts from Honda and see if there is any difference. I could also take a bolt out and measure the top and bottom of the bolt to check for any taper. I am a hobby machinist and I know that if your machine has wear and you turn something long and skinny, you could machine a taper in it due to the bolt “flexing” when turning or due to the wear in the ways.

                                  I am assuming the gasket will still be fine even though I already torqued these bolts down. But maybe I should get another gasket? I am still undecided on what to do next. I already threw away my old bolts like a dummy. I could have reused them to test this (they are not TTY bolts).

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