Fuel Vapor coming from Canister Area

Is it possible that you are overfilling the fuel tank? Also, have you checked tank vents to make sure they are clear?

Actually took this one to a garage today, and with a high powered light, they looked and determined the seal on the gas tank is corroded, and wet with gas. So every time you fill the tank and leaks a very little amount, over half a gallon. Garage wants $500 to replace the tank. I reckon I can do it for about $100-200. I did the one on the Mercury Sable, without blowing myself up, so just have to run the tank down so it's not so heavy, and get another one installed.

Is it the tank that is bad or the rubber gasket that is leaking?

I'm not sure, I haven't crawled under there yet. I would assume though, there isn't a rubber gasket around where the seal is, as my mercury didn't have one either. Its just a welded/crimped edge that runs along the entire tank. I suppose I can slide under there and check.

On another note, while I've got you. I assumed incorrectly that the valve that controls the charcoal canister was bad (under the trunk), and wasn't closing when it was supposed to, to draw extra vapor into the engine. I get a strange gas problem, whenever I turn my car at a T either left or right, and it "pops" inside the engine. Also does it whenever I go up steep hills. I can jam the pedal and it takes a few seconds, but eventually I'll climb that hill at 4000 rpm and 55mph. I've replaced the gas pump, replaced the fuel pressure regulator, was going to replace the above mentioned item. Car drives for the most part fine (except at low speeds, where it tends to chug), but its hard to start when it warms up, takes 2-3 key turns to get it going again. Seems to be getting worse. Blew out the lines, replaced the lines, new spark plugs.I'm at a loss at this point. It's the 1998 Mercury Sable DOHC, but basically has the system as the forementioned Taurus.

When you say it pops, do you mean backfire? Also, has the check engine light ever come on?

Yeah it backfires, a lot. It's not like my old Buick which made a backfire like fire coming out of the exhaust that sent the catylitic converter to hell, its more like popping in the engine. Once your not on a hill it settles down. And yes I have an SES light that mainly says, engine backfire and vacuum leak. But its insane how many gaskets I've tried to replace only to have the same codes and same problem over and over again.

The odd thing about all of this is, if I take the battery off and clear the codes, the whole thing will run fine, especially in colder weather. Its not until that SES light comes back on after 40-50 miles of driving, that it will act up. I actually drove all the way up to NH on the highway and had no problems for 3 days. But the second I got out onto secondary roads and drove around from stop lights and stop signs it started to backfire and misfire like crazy. Its the craziest thing to fix.

What gaskets have you replaced? Not to sound stupid, but is the throttle body tight? Have you checked for vacuum leaks using carb cleaner or something similar? If it keeps saying there is a vacuum leak, chances are there is. However, by disconnecting the battery shouldn't fix that kind of a problem. This is a tough one.

Let me know what you have done so far.

I know, I've been dealing with it in various forms for 5 years now. It always lacked power backing up. My old car I could drive backwards at 40-50 mph, this one, can barely handle 5-10. Now you may ask yourself why some idiot wants to drive backwards at stupid speeds, but if you get stuck in the mud and try to hit reverse, the engine just ends up backfiring like crazy.

I've had the transmission replaced and that sorta helped it, but then the problem creeped back up. Replacing the fuel pressure regulator helped to decrease the intermittent RPM at idle problem. Replaced the fuel pump, notably because when I went to test it, caused it to run dry and then HAD to replace it. Along with the fuel lines which broke. There's no smell of gas, and I noted on the charcoal canister that there is NO gas smell, and wonder if a malfunctioning Canister Purge Valve. This would be that thing up front near the firewall that sends gas fumes to the engine. Course it wouldn't explain no gas smell, but then maybe Fords Run differently than every other car out there.

I was looking at the above technical bulletin, and after downloading all the codes I get, going to take the engine manifold off and check the plugs and see what looks bad.

I went to Autozone and downloaded the following codes.

PO442 I've had this code since forever.

And PO420 also the usual code, even after replacing the O2 sensors in that bank (there's 2 of em)

But I also had a new code, for PO306, Cylinder misfire in #6. So we're gonna play with that today. And that could be anything I reckon, my guess is coil pack, since that's the most expensive, and that's usually what happens to me.

Pulled the plugs out and its probably a good idea to replace them all. Kind of a strange smell to them, not gas or oil, or antifreeze or trans fluid.

In any event, 2 out of 3 plugs in the first row actually have melted insulator ceramic shafts. As in where the black lines go around in a circle, there is a black heat deposit along the outside shaft where the wire plug connects to the spark plug. Never seen that before.

Sorry I didn't get back to you sooner. I was stuck working and as always, I got stuck with a job that ran into overtime. Lol You know, I think it would be easier to pull the engine on some of these cars rather than trying to work on them in the vehicle.

Your new code is a cylinder 6 misfire. What did that plug look like? And I have to say, I never saw the insulator burnt the way you described. How many miles are on the plugs you removed? Are they the correct heat range?

*Sometimes if we could flip cars over on a wheel, it would make life easier too*

It turns out, and I don't know how this happened but when I bought 3 Iridium plugs for the rear bank, because of the insane nature of having to remove the whole upper manifold to get at them, they sold me plugs that are about two nickels stacked on top of one another thicker than the plugs in the front bank. I just simply used some old 764 Double Platinums that were being discontinued in the front area along the fan, and used the more expensive iridium ones. So I guess they are referred to as being a "hotter" plug because more plug is in the area where the explosion happens in the cylinder itself.

The fun part is, the iridium ones aren't even for this car. They are for a 90-97 Ford Mustang. Oddly enough, I think they really worked good, and were nowhere near as worn down on the points as the "right" ones were in the front. Probably went about 50k on what should be a 100k plug. Testing the wires, I didn't get a shock along anywhere, and each wire had a good spark.

I took out a Warm Coil pack. And it seemed to be slightly out of the range it should be. The thing that is bugging me really bad is, when I first started I tested the Coil Pack at 1.0, 1.0, 0.5 Ohms on the Primary winding, and I forget on the secondary, but it was 0.2kohms outside of the range it should be. Now when I test it cold it's 12.8/0.5 on all coils.
The new one I just got from Amazon, tests out at 13.1/0.5 on all coils. Did I just buy a coil pack for no reason or what?

Coil pack is slightly out of range. I'm getting 1.0, 1.0 and 0.5 on the 4-3, 6-2, and 1-5, respectively albeit it was cylinder 6 that was misfiring. But the secondary winding has everything at 13.3k ohms, which is.2k outside of specs. That was 4 days ago, when I tested the coil warm.

Today I tested it again, and got 12.8 and 0.5 across the board, after 4 days of sitting on my desk.
I bought a new one, and that one is 13.1 and 0.5 cold. Am I a moron?

I think the one you had should have been fine. However, I am concerned about the different plugs. A hotter plug can cause damage to the engine. Have you now replaced all the plugs?

Yes, I'm working on it. I was going to leave the ones in the back, which are the longer ones, are they hotter or colder? They looked great, (@$6 each they should be), and far less crappy than the ones in the front which were the right set.

I went to Autozone to check out a Duralast, and I get 0.5 across the board, but fluctuating resistance of 12.79, 12.66, and 12.62 from left to right. I definitely do believe the MSD Street Fire is better, cause at least its consistent across the board.

I like your answer. I'll assemble it up and see how it goes.

Let me know the outcome.

Righty-O

Got everything back together, per my usual way, but I think I cleaned too much and used too much carb cleaner, as I'm having a hell of a time getting it started.

Still haven't gotten it started. I know I put everything back the way I had it. But it just will not turn over. New Plugs, everything was tightened and set right where it was according to the diagram for the firing order. All the hoses are reconnected. I just can't figure it out.
Unless the new coil is defective.