Mr 1999 Crown Vic will not stop misfiring. I have tried everything.

maybe check the alternator?

>>17465837
hurr durr take it to a mechanic you bullshitting cunt

stop making these fucking bullshit threads

> hi guyz theres a weird problem with my bmw
> hey here's a strange problem with my car pic related its someone else's car but I swear its just like mine lulz

>>17465837
Maybe the compressor is locking up

>>17465863
Hello Autismo Maximo.

>>17465860
possibly this. Symptoms sound similar to diagnosing alternator failure through headlight dimming.

Get someone to stand outside your car, put the fucker in P and rev it a little with the lights on. If it dims or brightens in either of the headlights, get yourself a new alternator.

File: vic in shop.jpg (1MB, 3264x1836px) Image search: [Google]

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>>17465863

I can't figure out what point you're trying to make here.

>>17465866
I Don't know, the AC works perfectly, so I kinda doubt it.

I wonder if it possible that the engine just can't put out enough power to do everything it needs in the described instance. Like, maybe everything is fine, but the AC sucking so much power that the engine simply can't do it's job properly. My Crown Vic has the 2.73 gearing, which is the tallest gearing, which definitely contributes to the problem. Cars with lower gearing would have far less strain on the engine at low RPMs.

>>17465837
So the parts cannon didn't work, eh? You might try looking at the data now? Fuels trims, etc?

>>17465891
It's probably the alternator. While you're replacing the alternator, you could install overdrive pulleys if you think your car isn't giving enough power to auxilliaries, but you'll notice a drop in power. Your car must be slow as shit with such awful final gear ratios.

File: vic.jpg (3MB, 3072x2304px) Image search: [Google]

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>>17465876

I'm not following the logic in how the alternator could cause the misfire at high loads. Is it that it's not putting out enough electricity or that it is unnecessarily/excessively loading down the engine?

The alternator on these cars is notoriously weak. When I am stopped at a traffic light with the AC on, the voltage needle bounces up and down when my turn signal comes on and off. That kinda tells me that there definitely isn't a lot of current to spare coming out of that alternator.

>>17465897
Yeah, I could look at that data using my OBDII tool, but I don't have the expertise to know how to analyse it and know what is good and what is not. I guess I could post it on /o/... On Torque Pro (my OBDII App) there is a function called "Misfire Monitor," but it doesn't seem to work for my vehicle.

>>17465907
My car is extremely slow. That's the nature of the heavy, under-powered panther platform. The 2.73 granny gearing makes it get 30MPG on the highway, but makes the car extremely slow.

What exactly is the logic that points to the alternator? Are you thinking that it is putting an unnecessary drag on the engine?

>>17465918
I don't really understand how it'd give you misfires on engine load, but it'd make sense at idle. What points to me is that it misfires when you've got AC on and try to increase the voltage by accelerating, which I've never heard of happening with AC before but I guess if it happens with headlights it could theoretically do it.

I'm just talking out of my arse here, but it's what sprung to mind for me because I had a similar problem with the headlights dimming and my car misfiring at idle (I too, replaced my ignition coils to no avail) and the alternator replacement fixed it. 2007 BF Falcon 4.0L I6.

Auto-electric gremlins suck. It's a case of eliminating the problem so it can get expensive if you don't know what it is precisely. I'd honestly just take it to a good mechanic / autoelectrician.

>>17465918
>>17465951
I forgot to add, does it start up fine?

>>17465918
>I'm not following the logic in how the alternator could cause the misfire at high loads. Is it that it's not putting out enough electricity or that it is unnecessarily/excessively loading down the engine?
>The alternator on these cars is notoriously weak. When I am stopped at a traffic light with the AC on, the voltage needle bounces up and down when my turn signal comes on and off. That kinda tells me that there definitely isn't a lot of current to spare coming out of that alternator.

Never had this issue on my 98 Grand Marquis. I'd definitely get your alternator replaced.

>>17465955

It does start up fine. I


>>17465951
>>17465964
Ok, I'm pricing them out now. It makes sense to throw a new one on there anyway, even though I am not sold on the alternator as the source of the problem yet.

My problem is for sure an issue of engine load. My engine cannot run smoothly at circumstances where its load is highest, which is cruising on the freeway and going up a hill/accelerating in overdrive with the TC locked. And the AC running. It is only in those specific circumstances that the misfire occurs. This makes it even more difficult to diagnose, because it can only be reproduced in that way.

The way I see it, there are two possible main issues here. Either the ignition system on the engine is not doing its job properly which is causing the misfire which occurs at a situation in which the ignition system is most stressed, OR the ignition system is fine and the engine itself just does not physically put out enough power to move the car, run the AC, power the rest of the accessories.

Unfortunately, it's pretty much impossible to test for one or the other.