Re: Strong engine stumble Reply #15 – June 29, 2020, 08:07:57 AM WOW!!! reading all this sounds just like what the year 2020 would be dishing out.ive said it before,,,these cars are getting to a point where they have exceed all engineering expectations and as time marches on, some of the things we never looked at before are starting to show up as the problem.so.... put this one on your diy list of things to do..............replace the three capacitors on your eec mother board sometime soon. even when these caps are somewhat bad, the eec still functions and the only results you get are odd ball intermittent problems. Quote Selected
Re: Strong engine stumble Reply #16 – June 29, 2020, 08:39:23 AM so.... put this one on your diy list of things to do..............replace the three capacitors on your eec mother board sometime soon. even when these caps are somewhat bad, the eec still functions and the only results you get are odd ball intermittent problems.Any link or info on this and how to do it? Thank you. Quote Selected
Re: Strong engine stumble Reply #17 – June 30, 2020, 09:55:39 PM Beleive it or not, but I believe this to have been like this since I owned the car. The entire time I've owned this car, its gotten bad gas mileage (between 20-25 freeway) and its had an intermittent stumble that I just couldn't find. I have occasionally gotten an o2 code and even swapped out the side that had the issue twice. Both times I assumed that it was fixed because it seemed like the issue went away. Even after I did my head gasket, it seemed to run better, but I was bummed that it still had a miss. I did a basic tune up on it and couldnt find anything wrong so I jist left it as is. I've owned this car for about 3 1/2 years. In that time I've put around 120k on it. I though I knew it pretty well and had it pretty well figured out. In all that time, ive only been able to chirp the tires on wet pavement. Not only does the stumble seem to be gone, but the intermittent issues as well. I haven't quite ran a full tank out of it yet, going to do that over the holiday weekend. But it also seems to have all kinds of power down low. Up top feels about the same, but I can now spin a tire from a dead stop and keep it spinning.I honestly believe that wire was messed up the whole time ive owned the car. It also had a brand new o2 sensor on that side when I bought it.Its not perfect, feels like it might be pinging a bit at low rpms/high load, and feels like it needs a real tune up. Maybe its time to change the oil and air filters for the first time. Quote Selected
Re: Strong engine stumble Reply #18 – July 01, 2020, 08:41:29 AM Quote from: Haystack – on June 30, 2020, 09:55:39 PM Maybe its time to change the oil and air filters for the first time.Please, I hope you are joking, at least on the oil. lol Quote Selected
Re: Strong engine stumble Reply #19 – July 01, 2020, 08:12:09 PM Quote from: Haystack – on May 25, 2020, 05:21:50 PMSo I went out to the car and the battery was dead. I hooked up the jump box and didn't even try to start. Got out to cables and something was visibly on fire under the intake manifold near the rear bell housing.Shut off the jump box and pulled the cable. I was able to blow out the visible flames. But I am at a complete loss. I've never had a car catch on fire, and the only wiring I could see In the area was the o2 sensor harness. Fuseable links don't appear to be melted. I am not going to have a chance to mess with it until next weekend. Gotta be in bed by 8 and up by 4:30 in the morning for work The O2 heater should only have power when the ignition switch is in RUN. May want to check the condition of the ignition switch. The fuse link is the ignition switch power. Quote Selected
Re: Strong engine stumble Reply #20 – December 17, 2024, 06:32:55 PM I know everyone's been dying for an update on this. It was definitely the O2 sensor harness. I took a much closer look at it last winter, and the old harness had a sharp solder joint that could touch the bare ground. The power and ground wires are spliced right at the "t" and looks like some sort of solder connection. When it shorted out, it killed the computer, and was causing the intermittent stumble I was fighting for so long. Mileage is up, went from 20-25 to a new best of 29, averaging between 25-28 mpg highway. Life has really gotten in the way, I have been working out of state alot, and just haven't had the energy to really mess with the car. It's a bit over 275k miles now. It blows blue smoke and eats oil like crazy now, the longer you run it, the worse it is. For some reason, the transmission started neutral revving when it's below freezing. Still doesn't slip once warm, but it feels like it's on its last leg. I also wrecked my other 86 (135k miles). No injuries, I drove it home after getting smashed between a lifted Chevy 3500 and a tow truck towing two cars. Every panel, tail light, trunk and door is smashed pretty good. Insurance called it a no fault accident, so I just ate the car. It was pretty interesting driving it home though. The drivers side front fender got pushed up and over the tire. Plan is to swap the running gear between the two, and drive the wrecked car with the bad engine to the junkyard down the road from me. I do plan on dropping the oil and maybe taking a video just for fun before I pull it. Curious what a 150k mile oil change will look like. Quote Selected
Re: Strong engine stumble Reply #21 – December 17, 2024, 08:02:17 PM ping eric as well on your evtm question.he called me a year and a half ago and i sent him access to my dropbox to a shiznit ton of evtm's,, i think when he downloaded they got erased or something,, the only survivor link up on dropbox is my 87 evtm.you need an 86 i think and i can upload that if you want and send an open link Quote Selected
Re: Strong engine stumble Reply #22 – December 18, 2024, 08:14:33 AM https://www.coolcats.net/documents/All manuals from 1983-88 are in there (thanks Scott!). Quote Selected Last Edit: December 18, 2024, 09:07:04 AM by EricCoolCats
Re: Strong engine stumble Reply #23 – December 18, 2024, 04:36:52 PM no worries,,,i gotta get my act together on these uploads,, and dead links.Haystackive got 375kmi on my 302 20th,, i feel compelled to credit rotella 15w40 diesel engine oil. plus changing the oil often sure does help.I started this habit long long ago because one day i changed my oil and after a trip 50miles round,, i came home and checked it and it was sorta dark again. from that day forward,, about every third oil change i use 4qts of cheapes oil to keeping the old filter,, then drain the cheap stuff, add new filter and new rotella. ive noticed it kinda flushes hout the motor and keeps the oil looking good and carmel in color much much much longer than before.If you happen to have a spare 302 oil pan that has a low oil level sensor provision,, i could use one... jcassity@frontier.com or 3047724082 to discuss cost ,, i appreciate it.i am still wanting to experiement on a two piece oil pan since i now have the sheet metal splice strip i found from BLine. Quote Selected
Re: Strong engine stumble Reply #24 – December 19, 2024, 02:23:29 AM I checked my storage today, my oil pan was smashed, and I already stole the good one and forgot about it, sorry. If you want a front sump smashed oil pan that leaks, I'll send it to you for shipping cost. It isn't smashed badly, motor mounts ripped out and the front corner washiznitting the sway bar and I didn't notice until it was leaking. When I was 16, knew nothing about cars and was a pen 15y know it all, I decided I was going to do an h.o. swap and bought a brand new (remanufactured) engine. When I got married, money obviously was tight, I ended up buying a car with a bad engine, I was really excited to throw all the parts at it. I got it all put together, dropped it in the car, and not only was the engine bad, but so was the transmission. Had a very badly skipping first gear and 3 neutrals. Didn't even make it around the block.After trying to save up for a new or rebuilt trans, I gave up, picked up another cheap t-bird that was listed as "non-running" food trans, which I got for a song, I think I paid $150 for the whole car due to an "electrical fire", sight unseen. After it got dropped off, it was in much better shape. Since I already had an extra wiring harness on the stand, I figured it might be cool to see if it will try to start and verify the engine works before I swapped cars, so I decided to see how bad the harness was. Single bad fuseable link, replaced that and the car fired right up, it had lower miles, and was in much better shape, but also removed the reason why I "needed" to swap the engine, so the now ex-wife said we'll just save it for now, and when it blows you can spend money to put it in. So I ended up saving the engine and junking the other car. Since then (about 2006), I have only changed the oil if it was a needed thing, meaning I had to drop the oil pan for some reason, and I have tried as hard as I could to blow up every cougarbird since. My current 86, the one with 275k miles, I drove it home, 50 miles on the highway when I bought it in first gear bouncing off the rev limiter. I figured for sure it would fail, it had a bit of a stumble, and a bit of an exhaust tick, so I was sure it had a bad lifter. I drove it as is, hard as I could, trying to blow it up. If the oil got low, I'd wait until the oil light was flickering at idle, and keep driving it until I got done with whatever I was doing that day, and then I would throw 1 quart of the cheapest oil I could get at it. I don't think I ever once pulled the dipstick. Again, that was 135k when I bought it, after 9 years, it's at over 275k last I checked, the dash lights have been burned up so I can't read it for the last 4 or 5 years and I haven't checked since. Eventually the exhaust tick and stumble got really bad, I also started blowing coolant. Again, I topped it off when the engine seized from overheating, otherwise I just drove it as is. It got bad enough I started blowing radiators and heater cores, so I decided to pop the valve cover to see how bad it was. With how much I beat on it, and overheated it, I was sure it was a blown head gasket, secretly hoping for a cracked head. Instead, I found that it was missing a head bolt, just one between two cylinders. Engine looked mint, no metal shavings, I even pulled a few lifters and they had some wear, but it was really clean and even, hardly a single scratch on them. I pulled off the head, head gasket wasn't even blown, but I already bought the kit, so I replaced it anyways. Only replaced the gaskets and the one busted head bolt, and it ran like a top, minus an occasional stutter that came and went, which is what ended up being the o2 sensor harness. After I fixed the O2 sensor harness, car still ran good, only used about a quart of oil a tank, so I just topped it off. Oil filter is rusted with almost no paint left on it last I looked, but has a thick layer of black gunk, likely oil mixed with dirt (I often drove on dirt roads). About a year ago, I think the valve stem seals all have up, that or the oil rings. Now I can't keep oil in it, blue smoke everywhere, uses a full 5 quarts in half a tank, not worth driving anymore with the cost of the oil so I parked it. Quote Selected Last Edit: December 19, 2024, 02:24:58 AM by Haystack
Re: Strong engine stumble Reply #25 – December 20, 2024, 07:21:13 PM i have read this 5 times,, and twice to friends and all of us had all kinds of laughs. i swear to god there should be some sort of movie or comedy about your so relaxed and laid back attitude and how hard these cars keep trying to prove to you they are worth saving... good story,, should be a sticky Quote Selected
Topic: Strong engine stumble (Read 6097 times)
previous topic - next topic
