The service engine soon light came on on my 2000 F-150 yesterday. The truck was stumbling under acceleration and shaking quite a bit. It has been raining for the last three days and it seemed to start after the first day of rain, the reason i say this is because ive heard that fords sometimes have problems shorting out with damp air. Could this be a possibility or any other ideas? Help Please!!

 

You should get the code, but it sounds like a misfire due to moisture on an ignition coil. If the MIL blinks a few times and then stays on, it indicates engine misfire.

 

I think that you were right, today it is 65 and sunny and it runs fine. Is there a way to fix it so that i can drive it in the rain? And what is the MIL light? Thanks.

 

You need to check your spark plug wires. If this only happens when there is heavy moisture in the air, then it indicates that moisture in getting past the boot and inhibiting the spark.

One of the boots could just be loose. You may want to pull off each boot and put a bit of dialectric grease around the edge to help keep moisture out.

As for turning off the MIL (Check Engine/Malfunction Indicator Lamp): If this were simply a random misfire, the light should turn off by itself in a few days. You can reset the computer by disconnecting the negative battery lead for a couple of minutes as well.

 

I have $ 10.00 says it was an ignition coil, because it KEEPS ON HAPPENING to me. Hope I'm wrong, for your sake.

 

The service engine light also came on in my 1999 supercab 5.4, went to auto zone ,they read the codes which indicated lean mixture on both banks,said both oxygen sensors should be changed if light came back on,IT DID, Anyone have input on this ,truck only has 24000+ miles on it . Please advise
Thanks in advance for any HELP!!!

Phoneman,
Again this is a great site, with great participants!!!

 

phoneman,

Do you happen to have the number of the code ?

I am guesing that these are P017* codes ( both a P0171 and P0174 ). The others are P1131 P1151 P1157.

The P017* codes are somewhat common, and if this is the code a few things to check.

1) have you replaced the air filter or installed a FIPK as of late ? If so check the IAT sensor installation, or the other hoses from the intake elbow to make sure they are on correctly.

2). Clean the MAFS it could be dirty and not reading correctly. ( Is the truck pinging under load ?? )

3) Check the 90* PCV hose boot on the back of the throttle body for cracks. Also the line to the PCV.

4) Check the vac lines to and from the EGR for cracks ( might as well check all the vac lines ).

Those are the big ones straight away to check and see with. If you do a search on the term P017* you will find about 40 threads on this topic. Check what kid triton and JMC have posted on it for the fixes.

The truck is more then likely trying to adjust for un mettered air in the system ( air not recorded by the MAFS entered via cracks or open hoses ) or a mis reading of the amount of air in the system ( dirty MAFS ).
If you have a pinging under acceleration under load, this is usually a sign of a dirty MAFS as well, could be the cause of both.

Try one thing at a time, disconnect the battery to reset the PCM and do a drive cycle, steady state over 48 MPH to check ( 2 times in the drive cycle usually to set the CEL ).

Good luck, and post back what you find out for the next memeber.