Misfire on cylinder 1

[dde2]

Hi Group,

I have a 2000 Windstar with the 3.8. I did the Isolator bolt thing a couple of years ago and changed out the EGR valve out at the same time. And up until about 2 weeks ago everything was fine (other then I have to replace the DPFE sensor about once a year) My wife was at the drive through of our bank and the van started running poorly. the check engine light came on and started flashing, according to the owner's manual it means it has a misfire. I had the codes checked and got a "Misfire on cylinder 1" In the past two weeks I have changed the plugs, wires, Coil pack, fuel filter, and the injector for cylinder 1. I get good spark on the #1 cylinder. (Hooked one of the old plugs up to the wire and saw good spark then replaced the new plug with the one I just saw good spark from after checking the gap of course.) A mechanic (A real mechanic not one like me, he has about 30 years experience and is GM certified) put a "Noid" on the electrical connector to the #1 injector and it shows good signal from the computer. While the van is running, I can pull the electrical connection from the #1 injector (just replaced today) and it makes no difference in how the van is running. If I pull the electrical connector from one of the other injectors the engin runs a lot worse so I am fairly confident that Cylinder 1 is the problem, but I cannot for the life of me figure out why it isn't working. I cleaned the EGR ports on all of the cylinders so i don't think that it's clogged.The van is still not running right and I am quickly running out of money and patience. Any ideas would be greatly appreciated.

[wiswind]

A new injector on cylinder #1 should be clean, and the unplug test would seem to indicate this injector.
However, I would try the Berryman's B-12 Chemtool anyhow.....worth a try as it is possible that some dirt got knocked loose.
It is a cheap thing to do, and has helped me with misfire issues a number of times over the years.

[dde2]

Thanks for the fast reply, I tried the B-12 trick ( got the idea from this forum) when the van first started running bad and it hasn't been driven more then 10 or 15 miles since (Slowly and with very easy acceleration). I just talked to the mechanic again and he gave me another thing to try. Before i pulled the fuel rail, I tried to release the fuel pressure via the relief valve on the front on the rail. I didn't get more then a few drops of gas out of there and when I pulled the #1 injector i got maybe a teaspoon of gas from the rail there. He said that maybe the fuel pump is bad (since the pressure was so low) and that may be what is causing #1 to misfire. He suggested I spray carb cleaner into the plenum via the rubber coupling between the throttle body and the air filter to see if that stabilizes the motor, if so the van is running to lean and may be the pump, if it runs worse it may already be running to rich and I have no idea what that will tell me.

[dde2]

Well, tried spraying the carb cleaner into the intake, didn't seam to make any differance so I have no clue what to try next.

[discnik]

Have you done a compression test on the cyclinder ?
Compression below 100 psi will cause a misfire.
Possible vacuum leak in the area of the #1 cyclinder is another likely cause.
One other possibility: You said you replaced the coil pack for that cyclinder, it could be that the module is bad. I have seen this on GM vehicles.

[dde2]

hi,

Mechanic did compression check, had 125 PSI on the cylinder. I've thought about a vacuum leak from the plenum area, I've taken it off four times, got new Iso bolts and gaskets from Ford. Felt and listened all around it as best I could to feel or listen for a leak. ( I did find one time where i forgot to reconnect the vacuum for the brake booster, got all excited, but it wasn't it.)

On the bad coil pack thing though... Wouldn't getting good spark to the cylinder indicate it's OK? I'm honestly asking because I am no mechanic, I just buy the haynes manual when I get a car and pick every bodys brain (like now) when I can't figure a problem out.

[discnik]

Sorry missed the good spark part.
I take it this is an all the time miss not just when warm or cold ?
Have you take a manifold vacuum test ? It is the only remaining thing I can think of. Vacuum should be 19 - 21 inches.

Let us know.

[dde2]

I read about a vacuum check in the manual, but don't have the equipment/knowledge how to do it. My mechanic hasn't suggested it but I will ask him about it tomorrow. Thanks.

[12Ounce]

You should do a compression test on the whole engine... to compare the cyl #1 to the other cyls. This test is a bit of trouble as all the plugs have to come out at once ... and therefore no one is excited about doing it. 125 psi may be low ... but you won't know until you know what the other cysl are doing. I would expect around 175 psi on each cyl if all is OK wear wise.

[dde2]

Well here is the latest. My mechanic called me this morning and said he wanted me to run another compression check on the # 1 cyl. he said that This time I should start the motor, and see what the pressure was, then release the pressure and see what it went back up to. Following these steps, I found that my initial compression was 120 psi, after release it dropped to 0 and would only rise to about 50 psi with reving the engine. he said that means that the valve spring has either cracked or broken, but whatever the case, it is not allowing the valve to seat correctly, causing the mis/no fire on cylinder #1. At this point I am going to tow it over to his place and let him do the work. I will post the final results when it is repaired just in case anyone else comes across a similar problem.

[wiswind]

Well, this is an overhead valve motor, so the spring is right there when the valve cover is removed.....and the mechanic will be able to see the rocker, valve and spring easily.
It is not a common issue, and I would not have thought of it.
Anyhow, it is good that you have something to work with.

Fuel pressure issues can be really tough to track down as the OBDII system on the windstar does not monitor fuel flow or pressure.
On the 2000 model year, fuel pump and PCM relays have been mentioned, as well as the fuel pump.
I would ask your mechanic to check the fuel pressure while it is in......just to be on the safe side.
Sometimes the fuel issue can be intermittent....at which point a good move would be to replace the above mentioned 2 relays, and see if that cures the problem before going to the expense (part and labor) of the fuel pump.

[12Ounce]

I have read of some valve spring issues. They must not be very prevalent. Makes me wonder how long I should try to keep my ole Winny ... '99 @ 251k miles now. A valve spring breaking is one of those things that can happen without any warning and there are no preventative measures.

[wiswind]

my '96 is at 207K miles.
It is just one of a LONG list of things that can "go" at any time.....on any vehicle.

[dde2]

Sorry for the delay in the update. I got the van back from the mechanic and he was right, it was a busted valve spring in the #1 cylinder. Total cost for the spring and seal from Ford....$10 + tax.

I spent nearly $400 over a 2 & 1/2 week period, but after I got it back I decided it really did need the new plugs, wires, coil, fuel filter.......... I don't drive the van much as it is primarily my wife's "Mom's Taxi" But driving home from the mechanic's, I felt it had much better acceleration then before, and on the hi-way had a lot more passing power. My wife agreed after she drove it. I guess I hadn't realized how degraded the performance had become over the 4 years we have owned it.

I guess the main thing to look for in this case is good compression on the first stroke, then little to no compression on successive strokes.
I hope this saves someone the frustration that I went through.

[12Ounce]

Sounds as tho you have a good mechanic. Glad it worked out OK for you.