Why is my engine misfiring when cold?

Tiny
USFCIRE
  • 2001 FORD WINDSTAR
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 225,000 MILES

My engine runs fine when it has had 5 - 10 minutes to warm up, but sometimes, not always, has rough idling and misfiring when the engine is started in the morning. I replaced the fuel filter because I did not see where it had been replace before and it was a cheap thing to try. I have tried to use iso-HEET and SeaFoam to help the problem, but nothing has proven to work. I would get codes, but the check engine light isn't blinking when I would be able to get to the store to check it. What are your thoughts? What's my next move?

I guess I really want to know if this is something I should just drop off to a shop or can I diagnose and fix on my own?

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Monday, June 25th, 2012 AT 1:46 PM

17 Replies

Tiny
RACEFAN966
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Has the engine light come on at all? Also my thought it get a can of mass air flow cleaner and clean the mass air flow unit. If the engine light has come on at all it should have set a pending code a good code reader will find it and then I can look it up and see if there is something we can check. Once the code it retrieved clear them.

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Monday, June 25th, 2012 AT 4:17 PM
Tiny
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The codes are as follows: P0171, P0174, and P0303

The guy at the store asked when I last changed the plugs and wires, I would say 5 years or 130,000 miles maybe. The wires look great on the outside. I bought a socket for the plugs so I can pull them. But what do the codes tell you?

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Monday, June 25th, 2012 AT 9:42 PM
Tiny
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Everything if there is a code set. Ok with P0171 and P0174 that tells me the computer sees there is a lean and rich condition happening (mass air flow cleaning). P0303 tells me that cylinder number 3 is miss firing change plugs and ohm that plug wire get me the ohms and length of that wire ok.

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Tuesday, June 26th, 2012 AT 3:27 PM
Tiny
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So change all plugs and maybe one wire, plus mass air flow cleaning. Where would I get at the mass air flow to clean it? Also, which cylinder is number 3? Sorry not sure about all that stuff.

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Tuesday, June 26th, 2012 AT 5:19 PM
Tiny
RACEFAN966
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Ok if you changed the air filter ever then that is where the mass air flow sensor is, the cleaner is available at your local parts store. Yes change plugs and maybe have to do plug wires should be all. It cylinder #3 that is miss firing is what P0303 means you have 6 cylinders so it should be the front one on the drivers side.

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Wednesday, June 27th, 2012 AT 1:06 AM
Tiny
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I replaced all the spark plugs, I will clean the MAF sensor tomorrow. All the plugs were corroded and most were out of spec. I changed them out with the Bosch 4+ platinum plugs. Did not check the resistance of the wire, thought I would do the plugs and see if that works. The #3 is actually on the side of the engine facing the dash on the driver's side, and is was easy to get to, so if I still have issues, I will check that. Since they cleared the error codes, I have not had any issues, but it could be helped by the fact that the days have been so hot here in Kansas. Like I said it was happening once in a while and only in the morning. I will let you know how the MAF looks.

Do I just take out the air filter and intake hose and spray to my heart's content?

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Wednesday, June 27th, 2012 AT 1:32 AM
Tiny
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That right #3 is on the back side, sorry I knew that was thinking in backwards on how the engine is place in there sorry about that. Hasn't been so hot here in North Idaho. As for cleaning the mass air flow yes take out the filter spray it out and thats it. Anyway sounds like you will have fixed it if there is anything else just ask.

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Thursday, June 28th, 2012 AT 3:29 AM
Tiny
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Yeah all is well regarding the misfire, just started a small oil leak earlier this week, a few days after an oil change, not sure exactly where, but I know it is up high. Air Intake Manifold area so I am not sure if that is something I can fix or if I need that done by a professional.

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Thursday, June 28th, 2012 AT 12:49 PM
Tiny
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If you have a mirror check the valve covers, check oil sending unit. The intake can leak oil out of the front or back of it but no where else really.

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Thursday, June 28th, 2012 AT 2:41 PM
Tiny
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The valve covers are good, what I am going to do is clean up the area and see where it is actually coming from. Is changing the intake manifold gasket tough?

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Thursday, June 28th, 2012 AT 2:51 PM
Tiny
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Depends upon your skills. I would be able to get you pics and torque specs and such.

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Friday, June 29th, 2012 AT 2:46 PM
Tiny
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Okay, well I am back here again because the misfire things has come back, but this time while the engine is warm. I checked the codes and I still have a P0171, P0174, P0303, but now I also have P1518 which is maker specific and I read somewhere that it has to do with the intake manifold. I cleaned the area where the oil was leaking and the drip went away, but then earlier this week it came back with a vengeance. If you could help out this one last time I would appreciate it, I really want to do this myself, but I need a reliable car, and right now, I don't think I can drive the interstate, and that is the key for me to get home (I only go home on the weekends). Please respond ASAP so I can know if I should schedule my car for tomorrow afternoon at the shop.

Thanks.

Eric

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Tuesday, August 14th, 2012 AT 10:18 PM
Tiny
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Well P1518 is solved. I will report back to you after I take the van out for a longer drive on the highway. It should be Wednesday or Thursday. This is where I got my answer: http://www.youtube.com/watch?v=XcTVfrAgTLk

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Wednesday, August 15th, 2012 AT 12:01 AM
Tiny
RACEFAN966
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Ok P0303 is cylinder 3 missfire. It could be either a plug or plug wire so check them both. P0171 and 0174 could be because of the P0303 so fix that first.

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Thursday, August 16th, 2012 AT 12:40 AM
Tiny
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Oh you went with bosch platinums that is why the missfire more then likely use autolite fine wire plugs. I have found that when I use bosch platinums I will have the car back with a missfire so I won't use them.

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Thursday, August 16th, 2012 AT 12:41 AM
Tiny
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Just as a follow up, albeit very late, I have taken the van to a mechanic and the underlying problem were six ports nearly completely clogged up and potentially a faulty fuel injector. Once these were remedied, the van runs great. Thanks for the help!

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Monday, March 4th, 2013 AT 8:47 PM
Tiny
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That is great that it is fixed. Thanks for the follow up.

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Tuesday, March 5th, 2013 AT 3:47 PM

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