I have a 2000 ford f150 5.4l 4wd. It runs really rough when I place it in gear with the brake on, less rough while driving. This occurred after some really abusive driving conditions. Error code P0305. It acts like a vacuum leak almost. I am wondering if anyone know what "misfire detected" usually involves.

Thanks,
Stu

 

Ha ha, it means C.O.P's, (coil on plugs) as far as I can tell. I never got a code but it looks familiar, like no. 5 is failing. I'm sure others will chime in here soon with definitive code meaning, but do you're homework now, search this code on here as well as google per say. If I'm right on the coil call, there really is a sickness going on like the flu for our trucks, in coil on plug form.

 

Is there any way to test the coil, I hate the whole halfhazard parts replacement scenario.

 

See, I'm not really that good at electrical, but I'm thinking they can be tested. Given the age of you're truck and predicted mileage, it's not uncommon. If replacing one, my advice is replace all. Maybe keep the old ones "in case", but if you confirm a coil bad, that's my advice. Ebay has cheap deals, I'd lean more towards a Motorcraft coil personally, number 2 would be motoblues, I guess they are good too.

 

Thanks for the reply, another thought I had was I may have water in the coil related to a BAAAD water crossing I made. I think I'll try some dielectric grease first as it's coming up on the last 3 days of bow elk hunting up here in idaho. I'm hoping to avoid wrenching this weekend.

 

If you grease the boots your 90% of the way to replacing the coils and the plugs. If it were me I wouldnt do that unless you plugs and coils are fairly new. I would just change them if your gonna screw around with them. getting the coils out to grease the boots is all the labor for replacing them. Getting em out while not that hard is time consuming and kind of a drag.

 

I purchased a new coil at the ford house today($97.00 I won't be doing that again) replaced the #5, I figured I could slip it in there easy and I did and it fixed the problem. Replacing the other 7 coils is a job I'll save for another day since it looks like it might take 4-5 hours. That way I can take more time acquiring the coils in a more financially sensible way. Thanks again for the help.

 

did you check the IAC. If you don't have a vaccum leak. You might check the idle air control. clean or replace. Fixed mine before, tried cleaning it but ended up replaceng it

 

If you clean it - use WD40 and nothing else to keep it tight - when you clean , work the mechanical's inside with hemostats or a small pair of needle nose pliers. The use of compressed is needed to force the lubricant in the right places - DON'T soak it.. - That worked for me , got 229,000 out of my stock IAC. Clean it right and they will last along time..

 

Yea, theres a way if you have a probe and pulse light. You have to test under a load during the drive cycle. Feed the probe thru the firewall gromet - clamp to the side of the coil you want to test. Have someone with you and go for a drive. Monitor the pulse light inside the cab and look for interuption during the cycle. You may have to do this 8 times to find a weak COP.

 

COP Systems - it usually means change the Coil - specially if the misfire monitor detects it .. It's pretty bad at that point..

I suggest a full COP change-out on your 2000 - That's the best tune up possible for these trucks

 

where is the iac located?? im having similar problems with my truck and i cant figure it out. everything ive done has helped but its still not running right. ive replaced the coils, egr valve, and o2 sensors. it runs a lot better than it did but it still idles funny when i come to a stop and im in gear. it seems like it should idle higher than it does.

 

Behinde the TB elbow on some models - others , it's along the side ..

 

thanks for the pics....mine might be diff. i have a 4.6 2002. what does it look like?? does it have a wire plug in it? is it metal or plastic?? im just trying to get an idea. how much is it?? should i just replace it or is it somewhat easy to clean??

 

Your might be on the side like this one..

http://www.fordf150.net/howto/throttlebodyclean.php