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.
Why replace something if you don't know if its broken?
I hate to say it, but there are really only maybe 6 wires the car needs powered up to run and there are really only a few critical sensors. The computer will tell you if things aren't working.
If you don't want to check if the computer is working, I really don't see much point in trying to fix the car.
It takes two minutes and a paper clip. Most 86's done have a check engine light, so we have to use a test light or a 12v buzzer or an buttstuffog volt meter.
Unplugged the o2 harness because I forgot how much of pain it is to get to. Hooked up the jump box and it no longer gives me an error and the car starts right up.
Soent about 30 minutes pulled the connectors off the o2's. One connector is melted at the o2, so i need to either replace the o2 or repin it with another and haven't gotten the other side fished out quite yet.
Started it up jist for fun. Idles a bit off but seems to have fixed the fire and hopefully my intermittent stumble and battery issues.
So 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
Well I've pretty much verified fuel is good as well as the computer and I have already traded out the tfi/pip. I have had a bad coil once. It was arching out to the fender. Honestly the car still ran good while it was doing that. Just happened to see it when I was topping off washer fluid late at night.
I'm down to wiring or fiddly things. Working 6 days a week, 10 hrs a day 3 hours from home is catching up to me.
I pulled the spare out of my engine (been sitting since probably 2007 and dropped it in. Car feels a bit lazy, might have gotten the timing a bit off, but it hasn't stumbled once since.
So I changed out all the spark plugs. One or two were pretty used up and way out of gap but non seemed to be super bad.
After that the car seemed to run much better so I left it alone. Of course it started the random sputtering again. This time I put the fuel pressure on the window. Couldn't get it to dip or do anything funny.
Ran codes again, smog pump (82) which is bypassed. And get came back (34) so I am gonna mess with that next weekend. Ran another engine cylider ballance test and it passed, no more o2 code.
Since its still been stumbling, I pulled the dizzy/tfi out of another car. Cap looked pretty good and so did the rotor button. Cars running pretty good, gonna try to drive it again tomorrow but I couldn't get it to do anything bad.
I'm not convinced its the tfi/or pip, but it should rule that out if I have any more problems.
All that sensor does is keep the heater from turning on before the car is warm. If you clip it then you can use the regular mustang style hoses and then the heater still functions perfectly normal, except the heater runs in winter when you turn on the defroster while you se the windows. I consider that alone a worthy upgrade.
Well, I habe an update. I dont think its the tfi or the o2 sensor.
While driving today a spark plug blew out. It wasn't loose, the center electrode was spinning and moving in and out of the outside body of the spark plug. This is the same side I had the o2 code on, so I think its all just bad plugs.
I didnt have any tools, but coasted into autozone, bought a $1.99 autolite and it is running much better. Autozone loaned me a socket and had it done in 30 second. Guess I'm gonna do the rest this weekend.
Driving normally at highway speeds, this past week I have picked up a strong stumble. So much so, it feels like the fuel pump or ignition is shut off.
Being as I picked up a cheap fuel pump from Craigslist, I assumed that was the cause. Hooked up the gauge and I have a perfect steady 42 psi with vac line off and about 34 with it on. Preassure rises with throttle, so everything seems to check out.
I run codes, I get a 91 (lean drivers side) 34 (get out of range) and a air injection code.
I pulled the egr off since its really easy to get to, and its stuck and has a ton of black gunk. Cleaned it up, and minimal preassure moves it in and out. Looked at the smog pump, and I have a missing hose clamp. Whoops, wonder how long its been like that. Hooked that back up.
Unfortunately, engine was too hot to do the o2 sensor, so I let it be for now.
After messing with the egr and smog pump, I ran codes again. They still show up, havent cleared them yet. I then ran an engine cylinder ballance test. The motor isnt running smooth, but I had just ran codes and figured why not.
Got a 90 the first time and a number 5 the second.
Now obviously the o2 is going to affect the car running well and that is in the works for tomorrow. Ive noticed a drop in gas mileage too, so if thats all it is it would make me pretty happy.
So the plan right now is to swap that o2 and see where I am at tomorrow. Ill probably pull the number 5 plug while I am there and make sure it looks okay, but the plugs aren't that old.
The real question here, I've lucked out pretty good on o2 sensors. The only time ive really had to replace them was for emissions. I never really noticed a big difference in how the car ran. Can a bad o2 cause my bad stumble?
