Why so rich?
 

I have a 97 F150 XLT styleside thats pretty much stock. 4.2 V-6, automatic power everything. K&N filter. Stock 255x16 tires.
Bought it a couple of months ago. Had 89k,but ran the vin and the engine was changed at 72k by the ford dealer.Also changed the fuel rails due to a recall. Engine runs pretty good gets 19mpg on the highway and about 14mpg in town. It seems that it is burning too rich,the exhaust pipe tip is black and occasionally when I shut it down I can smell fuel.Checked it pretty close and can't find any leaks external. Thought it might have a bad injector but it runs good and I don't get a check engine light. Does'nt miss or anything. Any suggestions?
(I am going to have another pre-smog check done to check for excessive hydro-carbons, if it does'nt pass,then the dealer did an illegal smog on the vehicle)
Thanks

Hi ALAMB

There was a post here a while back, somebody had the same problem as you. If i remember right, someone said to check the fuel presure regulator. If it`s bad it can cause your engine to run rich.

I hope this helps.

Larry. ;)

maybe its ok
 

Well, the black tailpipe thig is totally noramal for these trucks.(do a search in the exhaust forum it has been discussed a number of times)Every one that I have seen or owned has had a the soot around the tailpipe(especially the 4.2s).My truck-a y2k f150 4x4 with the six has it and I just had the 15k service.Dealer said it is in perfect running order.I think the way to get rid of the soot is to install an aftermarket ignition system.Good luck :)

Runs rich
 

Thanks for the info,I'll check the fuel regulator. I'm still going to check the hydrocarbon level. Maybe your right and there is nothing wrong with it.
Thanks again
Later