1999 Moutaineer 5.0 Slow to Start - Need Help

[ric232]

In the last two days, my Mountaineer has started requiring many more revolutions of the starter to fire up. And it momentarily seems like it starts weakly once it does fire. But within a second, everything is running fine. I think it is only happening on warm starts, but I'll have to verify tomorrow morning when I do the first start.

Background: The vehicle has 92,000 miles. Four weeks ago, I Sea Foamed and used the correct CRC HD Cleaner to clean my MAF Sensor. I've done this many times in the past with no problem. These steps helped reduce my pinging as well. Two weeks ago, I changed the spark plugs (Autolite double platinum gapped to 0.054". Before the spark plug change, the engine would stumble very slightly when cold, but really only the first time I hit the gas. That went away with the spark plug change. Up until two days ago, the thing was running beautifully, better than it has in years.

Any ideas? I'm afraid this might be a progressive problem which will eventually keep the car from starting.

Thanks.

 

[Turdle]

IAC valve??
Did you clean it yet???
A new fuel filter would be a good thing---

 

[ric232]

IAC valve??
Did you clean it yet???
A new fuel filter would be a good thing---

Sorry, new fuel filter about 2 yrs ago. Should be good. I have not cleaned the IAC valve. I'll do a search for the procedure. Would that cause the slow starting problem I mentioned or are you just recommending that as a maintenance step? The truck idles very smoothly right now.

 

[ric232]

Anyone? Is this an ignition issue of some sort?

UPDATE: Well, I cleaned the IAC valve and replaced the upstream O2 sensors at the same time (was planning on that anyway), and one of those two items fixed the problem. Not sure which. I'm hoping for MPG improvement with the O2 sensors as well.