1998 Windstar rough idle

I have a 1998 windstar GL with 180000 km on it. I have had no trouble with it to now and by the sounds of it I am lucky. I am getting codes of P0171 system adaptive fuel too lean bank #1, P1131 lack of HO2S switches-sensors indicate lean, P0133 upstream heated O2 sensor circuit slow response bank #1, P0306 cylinder #6 misfire detected. I have tested EGR valve, DPFE, TPS,MAF,VSS,IAV, these tested fine to the haynes book. I have also changed fuel filter, upper intake gaskets, upstream O2 sensor bank #1, plugs, plug wires, coil pack, pcv and hose for pcv. I have brought it to two garages and they both say the head gasket. I did my own compression test and all the front cylinders read 115 to 125psi. I get good compression on the front side but #6 cylinder misfires. At idle I can pull off #6 and #5 plug wire with no real reaction from the engine (one at a time) when I pull #4 plug wire off, the engine drops idle to almost a stall. The garages did not do a leak down test so how do they know it is the head gasket. This all stared when at a stop the engine would rev up to 1200 rpm then slow down to idle and it has got to when turning a corner it stalls. Please help I am running out of options.

Welcome Kitch.

Boy you're thorough. Nice work. Electricity seems fine, then, go onto the tubes. Check for leaks. My guess, considering all you have done, is going to be way simple. Start with the fuel line hoses that feed the dfpe. I've found mine full of white powder. Remove, inspect and replace if necessary, all the vaccum tubes.

Karl.

You have plugged your codes into the "Search this forum" box, right?

Yes I have plugged my codes in but none come up with #6 misfire (po3o6). I know if you have a misfire code on #1 and/or #4 your egr ports need to be cleaned. This is why I am stumped. I have cleaned the egr ports changed the upper intake gaskets to the new style. I am trying everything before I strip it down to the head gaskets. Thank you for the reply.

bad fuel injector? swop injector with other cylinders

Tried that moved #6 to #4 still missfire on #6. I am going to check the fuel pressure regulator. I was wondering if there is anyway to check it so there is a noticable change to engine rpm's. Either by increasing or decreasing the pressure in the regulator.

Perhaps the module that drives the injectors is bad, need some way to determine if cylinder #6 injector is getting pulsed correctly. I remember my son's vortec v6, all injectors fired at same time, I guess timing of inejector spray is not to critical, maybe cross wire with another injector? You have good compression, good spark, all that's left is fuel.

I did not think of that to cross the injector cables put #4 with #6 if all injectors fire at same time. I will hav eto try that.

The injectors are energized by the PCM......
When the key is ON.....1 of the 2 wires to each injector is HOT all the time. The PCM provides a momentary path to ground to energize the coil in the injector to provide the squirt of fuel.
If you know that the injector is good (and clean)......the most likely problem would be in the wiring to the injector. Even the plug connection at the injector. The PCM is not likely at fault.

Have you been needing to add coolant?

Also, was there a green stain on the Oxygen sensor when you changed it?.....this would be an indication of a coolant leak into the cylinder.
For your year.....a leak in the lower intake manifold gasket is more likely than a head gasket.
For a slight leak....Bar's Stop Leak should take care of it.

I would recommend changing oxygen sensors in PAIRS with Motorcraft brand ONLY. You can get Motorcraft brand for a reasonable price at www.rockauto.com
The code indicating a slow response for an oxygen sensor is most likely a bad oxygen sensor.
By pairs...I mean....both upstream sensors together....so that you have the same switching charactoristics. It is normal for oxygen sensors to switch slower as they get older. Changing 1 with a new sensor.....would most likely have banks #1 and 2 not switching at the same rate.

No I am not loosing coolant.

I am wondering after reading the forums that did the 1998 windstar bank 1 valve cover need to be replaced. If so how can you tell if it has been changed. It looks as if I have oil leaking on the fire wall side of engine down to tranny. Not lots but enough. At first I thought it was the tranny fluid but it is oil. Notice when I was changing the oxygen sensor.

I called my dealer ship and found out that it is the bank #2 valve cover. Sorry front of engine (grill) this is prone to missfire in the front with lean in the back. This causes more fuel to be dumped into the front to counter act the lean the the back cause flood conditions in the front. If anyone understands that.

if you have a cylinder 6 misfire, it can still be the EGR ports. If you pull the upper intake, you'll have ports to each cylinder for the egr, they are about the size of a dime with a small hole in the center. If they are all clogged except 6, you'll get excessive flow and a miss, especially at cold start up.

PS the way you check to see if you have the updated bank 2 valve cover is pull off the PCV hose on the left of the valve cover (left as you are facing the front of the car and the valve cover) and look inside. The updated ones have a small breather hole. No hole, no update.

I have cleaned the egr ports. The cel has gone out after about 2 days of driving after I have changed the O2 sensor. I still have spark knock I see there is a tsb for 99 and 00. Is there one for 98. I think I found something yesterday. I borrowed a vacuum leak tester and it pointed me in the general vicinity long story short it is either the evr or the vacuum lines to the evr or the electical conection. evr $132 cdn. vacuum lines $23 and $19. So far I have spentabout $1600 water pump, timeing gasket and labourer was about $1100.

The TSB for the valve cover and upper intake manifold bolts / gaskets is for '99 and newer. They started using a different intake manifold in '99 that was causing problems. This TSB does NOT apply to your '98.

Cleaning EGR ports is standard....normal service at the age / miles.

Vaccum leaks are an issue on almost any car.....and can be hard to track down.

Check the elbow that is on the top of the upper intake manifold......next to the throttle body. The Elbow points toward the firewall.....and goes to the PCV valve. They can develop a crack on the inside of the elbow.

Also, check to make sure that the dip stick is fully seated. The air that flows into the front valve cover to replace the air that the PCV takes out....is measured.....flows through the MAF with the rest of the air. So....if the dip stick is not seated fully.....air can leak in......which the computer does not know about.

Make sure that the red vaccum line that connects to the fuel pressure regulator is correctly seated. The fuel pressure regulator is mounted to the crome fuel rail.....on the passenger side. The red vaccum line connects to the top of it.

Double check to make sure that no vaccum lines have been bumped loose... There are a bunch of them on the back side of the upper intake manifold......back where you cannot see them....so you have to feel around back there.

I have a number of pictures of my '96 3.8L....that may help you find things....as your '98 will be very similar. http://community.webshots.com/album/201931518cScpNK

For the misfire, I'd suspect your coil pack. I was getting a consistant misfire on #4 and changed coil pack, plugs, wires, & injector and that fixed it. I believe it was the coil pack that was the problem, not the others.

For the p0107 code I'd say a vacuum leak. Did you try to spray carb cleaner around the intake and hoses listening for a stuble?

Yes I sprayed carb cleaner around but did nothing. I have also changed the coil pack. When I touch something around the evr valve the engine revs up like it is firing on all 6 then when I let go it drops down. I am going to take apart the upper intake and take a look at the evr and vacuum lines and connection will post tomorrow about progress.

EGR is not scheduled at idle, so the EVR shouldn't be causing a rough idle unless it's failed on, or your plugging a vacuum leak on what your touching.

On mine I seem to remember another solenoid back there. I think it also has electrical/vacuum lines also. I think it may be the purge valve? I think purge is scheduled at idle but again,it may be electrical/vacuum lines.

I'd suggest checking the connectors and pins on each solenoid as well as the vacuum lines. You did clean the IAC already, right?

Well 4 hours later and still the same I checked the evr resistance 33 ohms in the ball park of 30 to 70. Key on, it has battery voltage and also the dpfe. I tried all the vacuum lines they seem alright. Put everything back together except the air intake. I sprayed air intake cleaner in. This also left lots of room to get around in behind the intake close to fire. I sprayed around back there and the engine almost died. Now I know there is a vacuum leak but where. I think I will buy all new vacuum lines and fittings and try that.

I still have spark knock I see there is a tsb for 99 and 00. Is there one for 98.

With that kind of mileage and spark knock, have you decarboned the engine? The 3.8 is notorious for this. Mom's Mustang (72 year old driving a convertible) knocked like crazy - very rough acceleration. I raised the idle with warm engine, fed 1 bottle of Seafoam into it through an intake vacuum hose. You can slow the feed to be safe by sucking the bottle clean through a basketball inflator. The engine will cough and choke but keep it feeding. As soon as empty. kill the engine and let it sit. You've probably already made a huge black cloud. After 15 minutes, start it and run a can of water, yes water through it. Make sure of the slow rate so you don't hydro-lock and kill the engine for good. Take it down the road and stomp on it to clean it out.
I did this twice and the second time, much less smoke and she runs great. Sometimes, you can foul your plugs so a plug change is recommended.
Marc/Douglasville GA
98 Windstar
97 SHO

I hear of this seafoam but we can not get this in Canada. Two of my brothers live in Minni. I will have to get them to get me some and ship it up so I can try it. Thanks

I ran into something very strange today. I bought oil stabilizer fuel treatment. I put all that in and when I got home I tried something. When the cel started to flash I played around with #5 and #6 fuel injector connectors. I took #6 off no difference then took #5 off engine drop a little. Then I put #6 on #5 no difference. Then I put #6 back on and was playing with it with #5 off. All of a sudden #6 started to fire after about 30 sec. Then I put #5 on the engine would run on all 6 for 15 sec then die off again. #6 missfiring again. Has anyone had this problem if so what was it.

It sounds like you're trying to isolate a bad injector or wire. #6 is intermittent. Do you have an ohmmeter? It's time to buy one. A good diagnostician would attach a scope to the lead to look for a signal. I'd expect a square wave of some sort. A DC Voltmeter would register a voltage value that you can compare to a known good cylinder. You'd at least know that it's not the wiring.

Yes I have an ohm meter. I will have to check that. I am just reading the chapter on fuel and injectors. I will try some stuff this week sometime when I have time. But why would #6 start firing when #5 is unplugged? Then stop when #5 was plugged back in.

I check a few things this weekend and the injectors are fine and they are being feed the same as #4 cylinder. I took #4 off and left #5 and #6 on the engine dropped rpm. Then after about 15 to 20 sec the engine rpm climbed back up. I am guessing but the computer is adjusting to me taking #4 off. I kind of figured out that I have a vacuum like. I can hear a faint high-pitched whistle sound from the drive seat when I give the pedal a quick pulse. I have sprayed everything under the sun around in there but can't make engine rev up or down. Does anyone have any Ideas about where it could be if your hearing it inside, driver side, but not under the hood????

If you're hearing a vacuum leak inside the vehicle you will want to check your heater/AC control vacuum circuits (hoses). Seems like every modern vehicular system (HVAC, transmission, brakes, etc.) have a vacuum control system and computers and engines are very sensitive to a vacuum loss in any of them. Yet another reason why I prefer to work on my 1980 Bronco, everything is mechanical.

Would anyone know if a lean condition on bank #1 would cause a misfire on #6 cylinder, or are they two separate things?

Well update time, I just finished the lower intake gasket on the 3.8L windstar. It ran excellent firing on all 6 cylinders for about 3 min from cold start. Then it started to misfire on #6 again. I could here a high pitched whistle but could not find it. I was pretty tired so I got pissed off and left it over night and started it again in the morning. Same thing happened but this time I listened for the whistle at the start and it was not there as soon as the whistle came the engine started to act up. I kind of pinpointed the sound to driver side just inside the wheel well. You can really here it from the wheel well but you really have to strain to hear it from the top. I looked all over and sprayed everything to see if I could make engine do something but nothing. I think it is a gasket because the engine runs great until it warms up a bit but where I do not know. Does anyone have an idea. I replaced IAC gasket, egr valve gasket, throttle body gasket, lower/upper intake manifold gaskets, valve cover gaskets, and replaced the fuel pressure regulator.

Could your vacuum leak be in the brake booster? Try disconnecting and plugging the supply hose to the booster.

I should have said everything I did but this is also the rest that I did when I heard the whistle. I plugged the pcv at the upper intake, every line off the fire wall side of the upper intake. This includes the brake booster. This is why I do not under stand what is causing it that would effect the engine this way.