guyslp

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guyslp last won the day on October 5

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About guyslp

  • Rank
    Regular (100+ posts)

Profile Information

  • Gender
    Male
  • Location
    Staunton, VA
  • Interests
    Cadillac and Rolls-Royce cars, orchid growing, parrots

Previous Fields

  • Car Model and Year
    Sedan de Ville - 1989
  • Engine
    4.5L OHV V8

Recent Profile Visitors

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  1. I always like to give a "disposition report" at the end of these sagas. Short form: It was the spark plug wires. Two days of driving and not a bobble in any of it. When the set that was on it was removed two that were on the firewall side showed evidence of burning on the plug end. I am wondering if this is just age or if there could have been a problem putting them back on when the plugs were changed last year. I'll never know for certain. I'm just glad things are back to normal and my daily driver is just that again.
  2. Hello Gentlemen. Had a couple of insanely busy days. This model year is throttle body injection. I think PFI came along with the 4.9 in 1990 or 1991 (I can't remember when the 4.5 was supplanted by the 4.9). New plug wires are on tap for Monday. It's such a PITA to get in to install these, particularly on the side facing the firewall, that I'm having my mechanic do it. Thanks for all the ideas, which will continue to be followed up as next steps if the new plug wires don't resolve the issue.
  3. Logan, Thanks for this, too. It would be a first for me on an American car, but British cars (with which I'm all too familiar) seem to be rife with ground issues. This is easy enough to check, and to clean up, whether it happens to be related or not.
  4. By the way, if anyone has preferences as to fuel filter options or fuel pressure regulator options, please offer those and the rationale. I don't necessarily love AC Delco and AC Delco only. I have used Mahle filters in the past and this one looks interesting. Strangely, it says it has a fuel pressure regulator, but I know that's not the same thing as the actual fuel pressure regulator (which I can only find aftermarket at this juncture).
  5. Thanks. Anything that's easy to check and cheap as far as taking a "throw parts at it approach" is worth doing at this juncture. I want to be able to drive along again without this nagging fear that "this drive" will be the one where whatever it is that's causing this will finally crap out entirely. My gut tells me that if it's one of those two it's way more likely to be the fuel pressure regulator as I'd expect a clogged or partially clogged fuel filter to be a lot less intermittent in nature. Never hurts to put a new one on, though.
  6. Hello All, It's been a while since I've had time to be a regular visitor and contributor, but I'm back again because I have a problem that is driving me insane and that I am convinced is going to be a "simple fix" once the root cause is known. The car in question is a 1989 Sedan de Ville that's in marvelous condition and has been my daily driver. About 2 months ago while driving along at approximately 35-40 MPH I could feel a very sudden, sharp, and brief hesitation. The way I describe it is as a "semi-miss" as I've experienced a car with a true persistent miss before and it is far more transient than that. At the time if you stopped everything consistently felt normal at idle. As some time went by, idle would be intermittently rough, but you never knew when. At the time this generally happened when the car had not been running for too terribly long. I have had the car looked at, but as an amateur mechanic even I know that if you can't get the car to do whatever it's been doing when you have your hands on it, and for long enough to be able to diagnose it, it's impossible to fix and that's the situation I'm in. As time has progressed there has been some change. Now this behavior does not seem to happen at all when the car is cold or just beginning to warm up after a few miles of driving but only when hot. The speed at which it occurs has changed, too, and has gone up the scale to generally not kicking in unless I'm going between 50-60 MPH, up to just under 70 MPH. One can force the stumbling to disappear either by letting off the accelerator or by giving the car just a bit more gas to speed it up. The latest change is that after the car is hot and this behavior has exhibited itself while driving the idle is more frequently becoming quite rough. I have had the car throw an E30 code twice now when this has occurred if it gets bad enough, but it is always transient. If the car is turned off and turned on again it consistently resolves. It will, however, hold on until or unless the car is "power cycled." [There was also a stored E55 (I think, I don't have my notes right now, but it was definitely an E5X) code, but I believe that was historical, and it has not been thrown again after clearing everything.] Over the last year or so I have replaced the distributor, spark plugs, coil, and idle speed control motor (as I had been getting E30s in cold weather - the idle speed would remain excessively high for longer than it should have). All of these except the idle speed control motor were in place, and for many months and miles, prior to this behavior appearing and the idle speed control motor was an attempt by me to see if that would fix the issue, but it hasn't. Someone out there has likely experienced this exact behavior, or something very similar, and will recognize the root cause, or so I'm hoping. Any assistance in getting this resolved would be appreciated. Brian
  7. And now, gentlemen, the end of the story and it's a happy ending. I had to order the distributor cap and rotor and those arrived yesterday. Since it's been pouring rain for 2.5 days up until today I could not have done the work in my driveway anyway. I put the new rotor, distributor cap, and coil in a short while ago and she fired right up with the first turn of the key!! I thought I'd also add a photo of the old distributor cap with a note about what it taught me. Because the brass "washer" [brush clamping] part of the coil-to-rotor assembly was originally found as shown, beneath the base of the distributor cap, I had made the mistaken presumption that this was where it belonged. Upon getting the new parts it became abundantly clear that there was no way that this would work as the spring could not reach the contact point on the coil if you tried to place it with the washer below the cap not to mention that there was no way it could be kept in place such that the cap could go on centered around it, even if you held the spring from the top. Once I'd made that attempt/mistake it dawned on me that the hole in the center of the new cap was precisely the diameter of the "finger" [carbon brush] on the new assembly and with the washer part resting on the upper side of the distributor cap and the insulating pad over it between it and the coil the spring was just long enough to make contact with the pad on the coil. I hope this observation may prove helpful to anyone who may find themselves in the situation I was in and who's never worked with a coil-in-cap distributor before, as I hadn't. Thanks very much again to all for their assistance and observations.
  8. KHE, I agree on the coil only because I could still detect a spark even with the button gone. I have already acquired a new coil, so I will end up putting that in but keeping the old one as a backup. The new rotor and distributor cap are on their way along with a new set of spark plugs, though I may wait on the plugs until I'm feeling a lot more ambitious. The four on the front side would be challenging enough to remove due to space constraints, but the ones on the firewall side appear to be an absolute nightmare to get to. Thank you for your input. It is appreciated.
  9. For those curious I've added photographs of what was uncovered when the distributor cap and rotor were removed. It's abundantly clear where that button ended up. Two photos of the fuel injectors at the throttle body, too.
  10. I've owned the car since January 2014 and it's run like a top until it stopped doing so a few days back. It is more than a bit of a wonder how cars can run sometimes. I have to believe that something "catastrophic" happened as I doubt we've been tooling along in the current state for 3 years and 4 months now. The coil I bought didn't come with the rotor bushing and there is absolutely no evidence of heat sink compound on the coil that was in the car and nothing in the installation instructions for the replacement that makes any mention of same. Time to get the distributor cap and rotor.
  11. What is that spring part with the button called? This at least explains what I saw with regard to the black crap on the base of the brass bit. I've already got a new coil and will definitely pop off the cap and have a look around to see what's what. The rotor and cap are easy enough to replace, too, but I don't know if that little spring bit is included as part of that package or not.
  12. Some photos from what I've done so far. I have not installed the new coil since I wanted to check on something before I did. When I cleaned off the spring that goes between the coil and the contact in the distributor I may have stretched it slightly. I doubt this should make any difference since I imagine the tinned copper end is supposed to make contact with the metal pad on the bottom of the coil when the coil is placed on top of it. I imagine this thing is the functional replacement for the lead that came out of the top of old-fashioned coils and was connected to the center of the distributor cap and where that lead wire looks like it's made of the same wire used for the spark plug wires. If not please tell me what configuration that spring is supposed to be in. The photos are annotated. You will see on the +12V lead of the old coil what was still coming out of that slide connector during the cleaning process. The original crud coating was much worse. It was quite tar like but there is no hint of burning of the plastic on the connector or arcing on the metal, so I am presuming that some time in the distant past something got spilled into this connector that was not known to have happened or was blissfully ignored. It's obvious that this was not a recent development. Since then I've done at least six or seven cleaning cycles and you can see bare metal inside the slide connector in the photographs now. Unfortunately I failed to take any pre-cleaning photographs of that spring, particularly the brass base, which was more black than brass. Since I'm out of space to upload here, see the photos on this shared Google Photos album. P.S. to Logan: Thanks much for the ST-125 info. Just based on the weak strobing in my spark plug tester when compared to what I saw on my Buick I'd have to presume the spark is very weak. Depending on what comes back in comments based on the photos I will probably install the replacement coil next and see if she fires up.
  13. Next update. Thinking that this was likely the coil, I've acquired another to have on hand. When I removed the existing coil (which may be the OEM one for all I know) the small tinned copper spring with brass washer on the lower end the makes the contact between the coil and the distributor was very badly oxidized and blackish on the bottom side. The button on the bottom of the coil itself was thoroughly rusted. I cleaned all this stuff up first but no change. So, I thought, it's time to pull the coil. Well, lo and behold, the slide connector that serves as the +12V from the battery was covered in nasty crud, almost like tar, as is the female bit into which it slides. It's almost as though someone spilled something in there at one point and it's spent years coagulating. So, at this point I'm trying to get the female slide connector cleaned out by dissolving this crap with Goo Gone, which worked very well in cleaning off the male terminal on the original coil. I think I'll end up putting in the replacement coil anyway as the next step after that connector is cleaned out to my satisfaction. I only wish I could think of something that could be rat-tailed into there to give things a good wipe, but the thing is so small that's not practical so I've been doing cyclic "fill, wait, dissolve, dump, repeat" to get as much of this crud out as I can.
  14. Latest report. First, I'm presuming what the Service Information Manual describes as an "ST-125" (which clearly refers to a spark plug tester) that you're supposed to use to check for spark when cranking is just one of the good, old fashioned testers with a small light that strobes as spark is delivered to each plug. They tell you to test for spark at two plugs as the first steps. I decided before I started this to test on my 1996 Buick so that I would know what "normal" looks like when spark is being delivered during cranking. Well, I have spark, but very weak spark indeed, when cranking. I am coming to believe more and more that it's the coil but will continue through the diagnostic steps to confirm.
  15. Logan, I'm hoping this will end up being just the coil. OldCadTech, Yep, I intend to start working my way through the diagnostic steps on the page for "non-start," though I may jump in at the middle if the beginning is about checking whether the fuel injectors are injecting since that's been confirmed already. At least I now think I will probably be able to repair this here at home. This car is my daily driver and has been completely reliable until this incident, and I fully expect it will be again after the repair. She only has 117K on her so I should still have years of service left on her and I really like the car. This is an "interesting era" in that it has OBD but not that can be read like the later OBD cars can. It also clearly doesn't monitor as many systems, either.