I've been searching around on the forums here for the last couple hours, and I can't find anything that matches the problem I am having. . . So here goes:

My truck starts up fine in the AM when I go to work.. The idle is fine, but I notice when I give it WOT it stutters while accelerating.. Almost like it's being "cold natured".. *note* If I give it quarter, or half throttle, it's fine. Only when I start to give it ALOT of gas...

After a few minutes it runs fine.. No problems what-so-ever... But I notice when I get to my truck, again, for instance: during my lunch break, It does the same thing. . . I never really noticed it because I usually don't give it WOT.

Last weekend I drove to the mall.. My truck sat for around 1 1/2 hours, and then I got back in it.. It did the same thing again for about 1/4 of a mile..

Do you guys think it's just being "cold-natured", or could there be something wrong here?

This truck now has 115k (approx) miles on it.. The last time I took it to get the oil changed the folks told me I need a new "PCV" Valve.

other than this little thing, my truck runs teriffic..

Ken

Truck Specs:
97 F-150 4.6
Auto Trans
Ext Cab

 

Any ideas?

 

Ya, the PCV valve is due. They only cost about 4 bucks or so. How about the plugs? Have they been changed lately, or at all? I would say clean the t-body, and IAC (problem areas) but they more affect idle and start up really. Never a bad idea to clean them, the EGR too. Just some ideas.

 

not sure...probably PCV...kinda early for that, but that's probably your problem..._motes

 

4 bucks? Thats a long ways from "59.99" (like they quoted me).. I knew there was a reason I didn't have it done there.. I found the PCV valve on my truck.. looks like a simple job.. how tough to change the EGR Valve?

 

How about the cold start sensor. Works like the old automatic choke. It seems your problem is somewhere between cold start and warm up. I would check that as well. I had one go out on my 98 4.6L when I owned it.

 

Cold start sensor? First time I have ever heard of such thing.. I am going to see if I can pick one up & replace it..

Btw, the plugs & wires are new... new air filter..

 

hmm.... PCV is probably the most likely cause. But what about a fuel filter? Also, another thing I would clean would be the MAF...

 

Okay,
I replaced the PCV valve on my lunch break. Got some cleaner from the parts store, and I will clean out the MAF sensor tonight..

 

Yup, it's just the end that you have to replace on that tube, comes with a new grommet too. Sometimes parts are cheap. Couldn't believe how cheap a rad is from the dealer, half what everyone else wants, so I sprung for new floormats too. Happy days!

BTW, replacing the fuel filter is good practice too, in this case may be a solution, who knows.

EGR should be easy, but maybe not cheap, can't say never done it.

 

EGR looks like a breeze.. Couple bolts on the side of it & one tube with a larger bolt 90degrees from them..

 

does ur truck have original plugs n wires on it?

 

They were changed 25k miles ago..

 

This is a peice of another forum I found..

"Modern fuel injected vehicles sense the temperature of the engine through an engine coolant temperature sensor (ECT sensor), and change the injector pulse width to 'richen' up the fuel mixture when the engine is cold. It could be something like a bad coolant temperature sensor. "

I think this may be what DAWG is speaking of..

 

I'm not sure if this will help, but mine would do that at wot but only for a couple seconds then clear out. It was my plug wires. ususally between 3 and 4 thousand