missing issue

[lxtasy83]

Motor runs fine until it warms up then misses like crazy. I replaced plugs, wires, cap and rotor. Now im lost. Help would be apreciated. Thanks!

 

[jhammel85]

Hmm..

Have you checked for codes?

 

[wizkid00104]

Perhaps the oxygen sensor. I know those have to heat up.

 

[lxtasy83]

Well as am drivin home from work it started doin it again so I shut the truck off while drivin then restarted it and the miss will go away, does it everytime I shut it off then will start missin again a few seconds later

 

[jhammel85]

Definitely check for codes.

Since it happens when it's warm and you can shut it off (cool down?) and turn it back on to have it go away for a bit, I'm wondering about the TFI.

My TFI did something a little like this before it actually completely died on me when the truck got warm..Which is typical of a failed TFI Module.

Even though I feel that it's ignition related, Another thought could be some kind of sensor or even the oxy sensor. When a vehicle warms up it, it goes into Closed loop. This means that the computer is "paying attention" to the sensors..especially the oxy sensor that trims fuel levels. When a car is started, the computer is in open loop until certain criteria is met. Especially if cold....The o2 sensor needs to be heated to work properly.
After the sensor is heated up, the car goes into closed loop and the O2 sensor make their corrections.

If I'm not mistaken, I think this also effects other sensors like the TPS, MAF, ect.

1st things 1st though...I'd check for those codes before messing with it and potentially wasting money.

 

[lxtasy83]

Well now it did it when it was cold all the way to the grocery store, then on way home it never did it. Also my check engine light isnt on so how would i check for codes?

 

[jhammel85]

What year is your truck? It may not have one...

You check for codes like this:

http://www.fordfuelinjection.com/?p=13

 

[lxtasy83]

my truck is a 1988