This morning I had anticipated doing a major tune up on the ole nag so I'd feel comfortable driving from FL to WA in a few weeks. Well, when I cranked her over this morning she did nothing but spit, sputter and bellowed smoke (unburnt fuel) out the tailpipe. I shut her down, left her sit for a while and cranked her over again. After a few secs of the same she settled into her normal cold engine high idle. I did drive to the store and back and she seems to run fine but there's still a light fuel smell. Reminded me of using Seafoam, it was that bad.

I haven't done the tune up yet so here's what's there and when I last did it, my truck has 120k on it now.

Oil/Filter: Motorcraft 5/20 and S400 - 700 miles ago
Air filter: K&N drop in - cleaned 700 miles ago
Fuel filter: Ford parts - 5k ago
Rad fluid: can't remember brand - 5k ago
Cleaned OEM IAC even though it was pretty clean - 5k ago
Cleaned MAF - 5k ago
SeaFoamed - 5k ago
PCV: Ford parts - 10k ago
CPS & CMP: Ford parts - 17k ago
Plugs: Autolite APP104 gapped to .044 - 20k ago
Wires: Ford parts - 20k ago

I've checked for air and fuel leaks and haven't found anything but I did find a rad overflow hose leak at the overflow reservoir that was clamped and fixed. The current plugs at cyls 1, 2, 3 had carbon build up but 4, 5 & 6 were surprisingly clean. I cleaned the carbon off the plugs, checked the gap and put them back in which resulted in a slightly smoother running engine. MAF, TB and IAC still look clean.

Any ideas what could have caused this to happen?

 

well, this sounds like the problem i had, but i found out i left my MAF unplugged after i cleaned it. is it throwing any codes?

 

Sorry forgot to mention that no codes were thrown.

 

i dont know what to tell you man, somebody should chime in. that sucks. hope you find the problem. it does sound like a malfunctioning sensor of some sort tho

 

yea man thats the problem i was having with my old 97 grand am...the MAF was getting by passed by a hole in my air intake and makin her run like total crap...hope you get it figured out tho

 

check you o2 sensors, i work for dodge as a driveability tech, and im not sure about ford, but on a dodge the upstream o2 sensor (before the cat) is used for fuel calculations by the pcm, if it has gone bad it will assume a lean air/fuel ratio and dump more fuel into the cyl, hence the unburnt fuel coming from exhaust, like i said not sure about fords fuel managment system but just throwing out what i know. and your right around the milage that i normally start to see problems with the o2 sensors

 

You may need a new IAC, Prerunner-Ranger had a similar problem

https://www.ranger-forums.com/forum2...ad.php?t=67450

 

Could be 02 sensors though.

 

Tell her to quite chewin', sober up, and cut back on the cigs.

 

Hay now, it ain't cool to dis another man's nag...

Anyways, I pulled DTC's today and came up w/ P0302 - Cyl# 2 misfire. Thinking it may be as simple as a bad spark plug I went ahead and did the tune up I had planned on doing yesterday but this time used Autolite AP103 plugs. ...when I say tune up I mean everything from the belt to the O2's. Since that didn't fix it, I swapped the coil pack from a buddies 03 Ranger to mine but P0302 came up under pending DTC's so that wasn't it either.

I reckon I'll be pullin the fuel injector tomorrow for a look see. I've never messed w/ fuel injectors before so if anyone has any tips feel free to speak up.

 

Got it fixed - it was a bad fuel injector.