Windstar 3.8 Chugging/Missing

[12Ounce]

Man, I'm sorry you had the problem. Yeah, getting to that sensor is a real PITA. And the studs and nuts could have been stainless steel ... but that would have cost 5 cents!

Being the mechanic for all my extended family ... I get to work on many brands. They all have shortcomings. I still usually prefer Fords ... but I do a lot of re-engineering over the years if I keep one for a while ... and changing fasteners is high on my change list.

[BroncoJoe19]

Did you pull codes again?
After you changed the coil I suspect that you would have gotten rid of one or two of your misses.

Did you reposition the coil wires as 12 ounce suggested?
What was the result?

You can use a noid light to check for impulses to the injector of the missing cyl, or you can use a screwdriver held to your ear to listen for the clicking open of the injector.


how to check for power to injectors
A noid light is a small incandescent bulb in a socket with pins that plug directly into the wiring harness leading to your fuel injectors.

Popular Mechanics: Auto Clinic Expert Q & A -- Fuel Injection - Popular Mechanics
A picture and more information is inlcuded in the above link.

If all the above checks out, then consider a compression test or using a vacuum guage.


How to Use and Interpret a Vacuum Gauge

I hope you find this info helpful

[BroncoJoe19]

Normally a spark jumps a gap in the plug which ignites a fuel air mixture that is under pressure six times per revolution of your engine. It happens once in each cylinder per revolution. If by chance one cylinder fails to fire that is a missfire. IF multiple cyls missfire then you have multiple missfires.

What causes a miss? Not enough air, too much air (vacuum leak). No fuel,(bad/clogged injector, empty tank, low fuel pressure - dirty fuel filter,weak connection to pump , weak pump) no spark, weak spark, lack of compression, valve timing, burnt valve, spark/ignition timing.

When you replaced the camshaft position sensor, did you remove the synchronizer too? Or just the sensor? The synchronizer can be installed improperly.

In the 60's and 70's one could run an engine with a dead miss all day, but not so with the newer engines. I'm not sure about the 3.8, but with my 4.6, if I have a dead miss, the engine REALLY pukes. The PCM senses the dead miss, and to protect the CATs from overheating cuts off half of the fuel injectors. It goes into limp mode, and you can't get over 30 mph. When you have a dead miss, the fuel that should have been burned gets dumped into the exhaust and gets burned in the CAT causing it to overheat.

Did you reconnect your O2 sensors?

I just re-read this post, and realized that you never answered me when I asked if you looked for vacuum leaks.
Two things I suggest at this point is:
1. Look for a vacuum leak
2. Check and clean your grounds. (even the little ones to the fenders, radiator support etc.)
3. is your battery up to 12 volts or more?

Checking for vacuum leaks.
Some of the sensors and some of the actuators either read the amount of vacuum, or use vacuum to move controls, therefore it is important to the proper functioning of the engine that your vacuum system is fully intact. Otherwise one may get codes falsely indicating that there is a problem with a controller/actuator, or a sensor when in reality it is caused by a lack of vacuum.

Look at your rubber vacuum hoses (they are about 1/4 - 3/8 inches in diameter, if they are dry rotted or cracked, replace them. IF they slip on/off of their connectors too easily, they may have stretched out a little bit, cut the ends off, and put them back on.

You may listen for a leak. Sometimes using a cut off piece of garden hose is a good aid to listen with. Sometimes a cardboard tube (like from gift wrapping paper) is helpful. Just remember that whenever you stick your head inside a running engine compartment, that you are not wearing any loose clothing or jewelry that can get caught.

Another suggestion is to use a spray can of carb cleaner and spray around the bottom of the intake manifold, and the base of the throttle body assembly. IF there is a leak, you should hear a change in your engine.
Keep a fire extinguisher handy, or use water instead of carb cleaner (it works, but not as well.) Be aware that if you use water and the wires get wet and it runs worse... your wires may be bad, and the water is allowing them to arc instead of jump the gap of the spark plug.

Another suggestion is: to take a propane torch, turn it on (but don't light it) and move it over the vacuum hoses and connections. The engine RPM's will increase if there is a leak and the propane gets sucked in.

Courtesy of TheOldWizard ford-forums... Don't forget to remind folks to check the PCV valve, hose and grommet !

Courtesy Ramnasal ford-forums... Clamp off the hose that runs to the vacuum booster (brake booster) or pull it and plug it. It is possible that the diaphram on the inside of the booster may go bad and cause a vacuum leak.

[BroncoJoe19]

I don't know how it senses a misfire and generates a code, but there is something called a cylinder balance test. And it will throw the same code for a miss whether it is due to spark (lack of ) or fuel injector (no fuel).

I believe that the PCM can determine slight variations in the engine speed, or torque when one cylinder does not fire and contribute to maintaining RPMs. The sensor most likely to be involved in that is the Crankshaft position sensor (or maybe the camshaft position sensor. I always get their functions confused.)

You may also want to start considering a compression test. I don't know how you would be able to test Cyl #1.

BTW... there is a common vac leak on the 3.8. Right on top of the engine on the driver's side there is a rubber elbow that heads towards the firewall. Made my van run so poorly I bought a scanner, I was afraid that if I took it to get it scanned I may not have been able to get it back home.

98WinVacumDiagram.jpg

[BroncoJoe19]

As depicted in the above diagram, you can clamp off sections of the vacuum tree to see if it makes a difference.

[BroncoJoe19]

This thread is getting loong in the tooth, and I am starting to get it confused with others. Please when someone makes a suggestion, aknowledge it. 12Ounce's suggestion in post #14 is a good one, and is easy to do. If you had a scanner you could easily determine if the miss moved. You can still do it the old fashioned way, pull the plug wire and see if it makes a difference.

What is your plan from here?

[mark v]

OK if one plug is fouled I bet the other 5 are shot too. Always replace all plugs, not just 1.

[12Ounce]

Actually the two sibling plugs fire at the same time, each revolution ... one plug being on "compression stroke", and one plug being on "exhaust stroke" (some say a "wasted" firing). All this is for saving money ... one ignition coil (the Winny has 3 coils in the "pack") for two cylinders.

{This is done on all modern gaso engines with an even number of cylinders (I think). An engine of 5 cylinders, such as Volvo's ... I would think would have a coil for each cylinder. Some Volvo expert can verify perhaps.}

So if you swap cables, at the pack, for cyls #3 and #4 ... there should normally be no difference. But, in your case, perhaps the misfire would relocate to the other cylinder ... that would be beneficial knowledge!

[BroncoJoe19]

WIndstar coil pack ... how to test
http://www.ford-forums.com/ford-wind...afe-drive.html

[12Ounce]

You're on the right track, but I wish you had ONLY switched the #3 and #4 wires at the coil ... and reread the codes as a "first step". Sometimes "too much change" is "too much change" ... to keep account of.

A compression test reveals a lot of info. Its just a lot of work.

It would be very smart if we all made compression tests on our engines ... while running good, or even when brand new ... and keep this as part of our maintenance records. I bought a new German Ford (Taunus) many years ago. A factory recorded engine compression test was included in the documents.