My Expedition has about 70,000 miles on it and has been a little harder to start lately. I was thinking that it is probably time to clean the throttle body and plenum. Has anyone here done this? I have always done my own wrenching but have not dug into anything this new. Just wondering how big a job it is and what the proper procedure is so as not to mess up the sensors.

It has a throttle body and not direct injection?

Last year, we got a tune-up from the dealer on our ’00 expedition.
They called me at work and asked if they could clean the intake plenum, fuel injection intake... I forget the exact words, but when they explained it to me it made sense.
I “think” it added ~$200 to the bill.

(I just looked through the file box and could not find the receipt – it must in the car)

All engines have a throttle body - some older models had the injectors mounted in it, but most newer ones don't.

I recently cleaned the throttle body Mass airflow sensor and changed the spark plugs in my 03 suburban. It runs significantly better and smoother. Also I was getting a few misfire codes, and I thought this might help.

Not a difficult job - a little messy maybe. Hardest part is getting everything apart. Make sure you use the proper cleaning agents. The MAF needs a special spray to clean it.

I did it in two stages, and the spark plugs made the biggest difference. A couple of plugs were pretty difficult to get to, but it was not as hard as my son's V6 ES300.

Okay. I was thinking of the TB injection on my 93 suburban.

Yeah that's what I'm thinking too. Getting to it is the hardest part. Plugs cap and rotor are probably due as well. Sounds like real fun.

I guess I should get a service manual so I know how to get to everything, and how to put it back together.

I've lost a couple MPG on the freeway and I suspect this is the cause.

When is it hard to start - when the engine is cold or after a hot soak?

What exactly happens - long crank and no start, or ...?

It happens both ways. It might be partly my fault since I let go of the key when it starts to pick up. Up until lately it has always started easily but more and more frequently it does not now. I guess I need to get used to holding the starter on a little longer. After that it retards the timing and you can tell by the way it cranks and then it starts but since it never did this until recently I just feel it needs some maintenance. Probably the plugs but I figure the sensors are probably filmed over as well.

You see these a lot more than I to say the least so what are your thoughts?