I think it may be time for a new throttle motor. What do you guys think?

2006 Navigator 5.4 3v.
I have replaced the timing chains, phasors, plugs, coils and throttle position sensor.

It still has two issues. (1) I've noticed that it seems to surge away from stops instead of a smooth acceleration. (2) If you are driving and just let off the gas and brake to a stop, it seems to be fine. If you slow way down, like to turn into a driveway for example, and then give it just a little gas and back off, it starts to run rough and idle really low. If you pop it into neutral and rev it just a little it comes out of it and idles fine.

Does that sound like the throttle motor? If so, do I have to pay the long dollar for the Ford throttle body assembly or is the Dorman throttle motor OK to use?

Thanks guys.

 

Is it throwing in codes? Have you taken it to a tuner to see what they say?

 

Yes it is. We couldn't get the reader to communicate with the computer, so we took it to the dealership. They had to "re-flash" the computer, but came up with cam position sensors. Since then, we replaced the sensors and all the stuff listed above. Now it won't communicate again. Tried a couple different readers with the same results.

 

OK, replaced the throttle motor and there is no change. I tested the MAF sensor and it seems to be OK. The problem is so intermittent that we are having a really hard time diagnosing it. We still can't get the computer to communicate with any of the scanners we have tried.

Re-list issue; intermittent very rough idle. Most of the time it runs fine. With the throttle open, there has never been an issue. Occasionally when slowing to idle speed it will start to run very rough and sometimes stall. Have replaced throttle motor, timing chains, phasors, plugs, coils and throttle position sensor.

Any ideas?

 

I can't say for certain but a common issue in the 5.4 motors seems to be the IAC motor. It's an easy swap and fairly cheap part.