[Johnny K]

I have a 1996 Taurus with the 3.0 Vulcan. The other day the car lost all power while driving down the road and seemed to be missing on a couple of cylinders. I pulled over turned off the car and checked the obvious, and yes all fluids were ok with no antifreeze in the oil. I started the car back up where it ran fine for about 10 min, full power was restored and it ran just like it did before the incident. Once again it stated to buck and miss on cylinders. I dove it to the closest auto parts store and sure enough a code came up (something 300) that said random misfire on multiple cylinders. I was told it was most likely the ignition system and everyone including the dealer is tiring to sell me parts that go to distributors. Unless I am a complete idiot isn't the car completely computer controlled through the coil packs? Has any one had a problem with their coil packs? Does it cause the above problem or does it just stop working. I measure the resistance as described in my Hanes manual, and it didn’t measure exactly what the manual had said but I am sure there must be a range? Anything else cause this problem EGR? Fuel? The service engine soon blinked coming on which I was told means that the cats could be damaged by whatever the problem was. Any help and insight to this problem would be much appreciated.

John

 

[Dave1234]

I had a 96 Vulcan equipped taurus and sometimes when i stopped at a light the RPM's would drop to about 300, then rise, then drop again until they dropped to about 150 and the car stalled out. a friend told me it was most likely the idle air control acting up. I'm not sure if he was right since i wrecked the car before i had a chance to fix it.

 

[rocketfast321]

might be a bad injector or bad gas. Get some fuel treatment first

 

[Guest]

P030(x) codes are telling you which cylinders are misfiring. This is ignition based when you get these codes, so I would go ahead and check the wires and plugs. For the wires, you should have no more than 5k ohms per foot resistance. Actually, if they've never been done, now is probably a good time to do them anyway.

I beleive the Haynes also points out how to check the coil.

Some things that could trigger this intermittently are a bad crank sensor (it tells the computer when the engine is at #1 TDC), or a faulty cam position sensor. The cam position sensor (or synchronizer as Ford calls it) controls injector firing, as well as timing advance, etc. Either of these sensors being out of range should set a code though.

Since your car is a 96, it does not have a distributor. It has a synchronizer located where the distributor was installed in the earlier engines.

If you could, please get the codes and post them. That would help us determine better what your problem may be.

 

[Johnny K]

OK guys here is the complete story:

I had a check engine light appear about 6 months ago. At that time Code P0430 (Catalyst System Efficiency Below Threshold (Bank 2)). The computer was reset and the engine light stayed off for about 3 months. I reset the computer again and it stayed off until now.

Back to the first description I posted about the misfire:

Now I have two codes
P0430
P0300 (Random/Multiple Cylinder Misfire Detected)

From what I have read the PO430 usually does not indicate a bad O2. So if indicates a cat maybe I have a plugged up cat? If I do where do I get the y-pipe with cats for these cars? I checked the local auto parts store and they don’t stock the item. Do they make a y pipe without cats where I can put cheaper aftermarket units in?

I cleared the codes again and I am going to wait to see what I get. Hopefully I can sort this thing out.

How difficult is it to change the crank position sensor?

Thanks For the Help.

 

[sixfofalcon]

Persistant misfires can cause O2 codes because more unburnt fuel is in the exhaust. This MAY or MAY NOT be a permanent problem. If you drive on a bad coil pack, plug wire(s) or plug(s), over time, you may load up the cat(s) or O2(s)with contaminants from unburnt fuel and cause a problem. However, the code may have been triggered just by the presence of the unburnt fuel itself, and not necessarily because the cat(s) or O2(s) are damaged.

At any rate, dump in some Iso-Heet, change your fuel filter, and do the aforementioned ignitions troubleshooting procedures. These are the cheapest ways to start pinpointing the problem.

The CPS and CKPS are not that difficult to change, but they are much farther down on the list of likely failures.

 

[Johnny K]

New Coil
New Wires
New Plugs

Same problem. After about 45 min of driving it starts to miss on cylinders. It gets worse as you drive limiting how fast you can go.

I am diagnosing it as a plugged cat. Any thoughts? Am I way off? Any suggestions on part selection.

By the way How hard is it to replace a gas tank?

 

[Xmann01]

I actually had a random misfire code as well with some rough idling and bucking..... and I think some other bs code. I ended up replacing both front O2 sensors and all was fine and dandy. It may not be the same problem you're having but It might help... GOOD LUCK.

 

[Guest]

According to the service CD, the P0300 could be caused by recently running out of fuel (I'm guessing plugged up filter), inadequate fuel pressure (could be the pump, filter, or FP regulator), ignition problems (though you've replaced all that), Cam position sensor issues (which should also throw a code, but yours didn't).

One of the last thing it mentions is the pulse wheel on the crank pulley that signals the crank position sensor. The CD points out to check it for wobbling or looseness, and also being dirty. If it's wobbling or loose, the crank pulley will need to be replaced.

I'd go ahead and check the fuel pressure, and if it's not that, check the crank pulley.

Run a compression check as well, just to be on the safe side.

I think the P0430, as SixFo mentioned, is related to the misfire. Don't pay attention to it until we get the misfire solved.

 

[sixfofalcon]

I had an annoying intermittant stalling and rough idle problem, followed by a bunch of BS codes. Turned out to be either a bad ground or a bad connection somewhere. I would strongly recommend checking the engine-to-firewall ground before replacing any high-dollar items.

 

[Guest]

"all of your moneys are belong to SHO"

Sorry for the OT, but bwahahahaha! That is too funny!

 

[sixfofalcon]

Go ahead... laugh it up. I just bought a new IAC for no reason. If the CKPS fixes my problem, I might think that statement is funny again.

 

[Johnny K]

An update…


The car is still having the problem of random loss of power after the car warms up. It acts like it is missing but no misfire codes are in the computer. It was predictable, almost to a T, when the problem would occur which was about 10min after it was completely warmed up to temperature. Now it is more erratic. I thought the problem was fixed and it was just bad gas and I drove the car for an entire week without any problems. Once again it started acting up so I had the codes checked again and I have lean codes on both banks. I looked for vacuum leaks and checked manifold vacuum and everything looks normal and vacuum was good at around 20 hg. Fuel pressure was also tested and it was also fine. I drove with the gauge on the car for about 1 hour and pressure looked great.

Ignition parts are all brand new.
New fuel filter.

Any other suggestions?

 

[rocketfast321]

at normal engine temp look under the car at the cat is it glowing hot? Could also be egr

 

[Johnny K]

Forgot to add that at one time I thought it was a cat as well and hollowed both out to see if the problem would go away. It didn't. I was getting a bad cat code before all this happened so if I was to replace one the other would have to be replaced with the assembly. I figured this would be a cheap way to test my theory without spending the big dollars on the cats yet. It needs replacing anyway so I used the bad cats as a test bed. The car still stutters, but now cats couldn't be causing the problem.

Thanks

 

[Johnny K]

I also disconnected the vacuum line to the EGR. I got an inoperable EGR code but the "misfire" didn't go away.

 

[rocketfast321]

damn only happens at operating temps now that weird. :blink:

 

[Johnny K]

More info on the problem…

If I am going above 50mph and stab the throttle the car will shift kind of funny rev up to 3800 rpm and act as if there is a governor at that rpm. It won’t have any power and it stutters or misses while it stays at 3800 rpm. Sometimes when I let up after this condition occurs it will hang at that rpm after the throttle plate is closed. I eliminated the purge system for the fuel tank too because I blocked it off to see if the problem would still occur.

I am grasping at straws now so any info would help. Has anyone ever had a computer fail on them?

 

[rocketfast321]

recheck your ground wires around your battery.

 

[ict_Lx]

I'm having similar problems on my 96' duratec. I had the rack and pinion replaced. The guy who did it said that he had to take the intake manifold off to do something. I think that he might have put something back on wrong. The only other time my car has had the flashing check engine light was when I went out of town for a week and left my car parked on a steep angle. I got the flashing check engine light when I started it up for the first time when I got back. It went away pretty quickly though. Did someone say that loose spark plug wires could be the cause? When I have the hood up I can hear the plugs sparking and the engine missing if that helps at all.