My truck sat for an extended time a while ago and the ethanol fuel went bad. I was getting misfire codes as well as banks a and b lean codes. I bought 6 new Motorcraft injectors and some Archoil fuel system cleaner. The cleaner did the trick and the truck ran fine with the occasional cold start dead cylinder. After about 20-30 seconds of running, you could feel the cylinder coming online erratically until it would finally run normal and everything would smooth out and then the truck would run great the rest of the day. This issue seems to come and go with months of normal operation, then for a few days or a week, it likes to act up.

Yesterday morning, it started and ran REALLY rough and it smelled like it was running rich. If I ran the RPM's up, it would run fine, so I left to get to work. When sitting a red light, it would have an occasional stumble every now and then, but accelerate and cruise nromally. Started the truck up again to go home with the same symptoms but the CEL finally came on. I got codes for High Inlet Air Temp Range and Misfire on cylinder #4.

Cleared the codes and ran the data logger when I got home and inlet air temp was steady 110-112 degrees and there was no misfire since it was fully warmed up. Long term fuel trims were 1.10 and short term fuel trims were 0.99-1.00

This morning it did it again, but not as badly, so when I get home today, I am going to pull cylinder #4 plug and see if its fouled. If it is, I am guessing my injector is leaking down and is dumping too much fuel. Of course, #4 injector is buried under the upper intake.

Does the upper intake have to come off to change the drivers side injectors? If I am changing one, I am changing all 6 since they all have 180,000 miles and have had bad fuel go through them.

 

Yes upper intake has to come off but it only takes minutes to do and if it's the plastic version it has rubber o-rings around the ports so you don't even need a new gasket.

 

I have the aluminum intake. Pretty sure I bought a gasket for the upper when I bought the injectors, planning for the worst. Just have to find it now.

 

Got the upper intake off, cleaned the valley, swapped the injectors.

I moved the DPFE sensor out of the way to make room to put the manifold back on and both nipples where the hose go onto it snapped off. Then, looking at the hoses, the larger one was cooked and split where it goes onto the EGR tube. So a trip to autozone for the sensor and hose and by the time I got back it was 9:00, so I stopped for the night.

Drove the 95 F150 to work today.

Is it normal for the intakes on these 3.0's to be FILTY inside because of the EGR system? I almost feel bad about putting all of this back together without pulling the lower intake as well for a cleaning, but I need my truck back in working order.

Hopefully it all goes back together without much hassle. I am considering putting some spiral wrap on the plug wires where they go near the exhaust as some extra protection since the wires grounding out can cause misfires and codes as well on these engines.

 

Hey Bigred thanks for the help on my air con vacuum lines I think i got it fixed,,, but i need the same help with my DPFE lines got any pics or routes for those two hoses,,i think one goes to the EGR tube like you said in your post above ,,, my truck seems to have two places there on the EGR tube about 2 inches apart and that tube goes to the bottom of the EGR and both my lines are running from the DPFE to both of these nipples on the tube,,, that cant be right can it why would both hoses go to the same place,,,, can you see or post pic or route of the hose that does not ( DOES NOT ) go to the EGR,,, think it would run lots better and improve my gas miles to get these vacuums right,,,,,99 ranger 3.0 extended cab stick 2wd 155000 miles daily driver

 

Glad you got the AC sorted out. I think my truck knew I was enjoying the correctly working AC too much and started throwing this misfire cylinder 4 code just to mess with me.

I think once those nipples are in the EGR tube, they read upsteam and downstream of the direction of flow to the EGR valve and use the differential pressure to calculate the flow through the EGR. There is a larger and smaller nipple on the EGR pipe, the hoses go to the matching size larger and smaller nipples on the DPFE sensor.

 

ok cool then they are in the right place,,,, i guess them being so close together threw me a curve ,,,, and one is just a hair bigger than the other so they only go one way,,,, thanks again Bigred its nice to be able to talk to someone who has almost the same truck, when dealing with vacuum hoses,,, the diagrams under the hood might as well have been made by a kid with a crayon ,,, not very usefull ,,, i looked up a post and got a little better diagram but it showed the bigger hose going to the main vacuum tree,,,, well it might go there but it gets there via the tube,,,, not shown in diagrams,,, one more quick question ,,, how do you get your two trucks and your cougar to be posted on the bottom of your post,,,, or do you type it in every time ????? by the way,,,, had a friend with a old cougar that had either a 427 or 428 or 429 cobra jet under the hood,,,, talk about run,,, wow it was fast,,, late 60 or early 70 i think,,, it would pass everything on the road but a gas station LOL ,,,the old 289 where tough,,, fast old motors in the day ( probally one of the best motors ford ever built) but all mine where 2 barrel,,,, bet it scoots pretty good with the 4 barrel ,,,, thanks again for the help

 

Go to your user control panel "User CP" under where it shows what forum you are on the left side of a page near the top, then on the menus on the left a ways down, it says "edit signature".

That's where you can enter the info it tags onto the bottom of any post.

 

Thanks again Bigred

 

Got the Ranger all back together. Primed the fuel system and started the truck, it revved to 2000 rpm and died. Started again and it did the same thing. Did that about 6 more times.......

Started it and ran to the front and revved it to keep it running and I can hear a HUGE vacuum leak. Traced it to a vacuum fitting I forgot to reconnect on the rear of the upper intake just above the PCV valve. It went from that one fitting to about 5 or 6 different lines, so who knows what was lacking a vacuum signal along with the engine running extra lean.

Hooked it all up and started the truck. Ran a little shaky at first but settled down and idled nicely after warming up.

No CEL light and no random stumble thus far. Tomorrow morning will be the test when I start it after sitting over night. Took it to the gas station to fill it up and it is running well.

As a bonus, when I pulled the #4 plug, which looked normal, I found my random exhaust leak. The bolt for the header flange under the #4 header tube had been walking out. So I tightened that down and have to see if my random exhaust leak is gone that would only occur when running the truck hard and would go away after cruising easily and the headers cooled back down.

And, spooktn, check out a youtube channel for a guy named ChrisFix, he has a 2000 Mazda B3000 and has plenty of videos on repairs for this series truck.

https://www.youtube.com/channel/UCes...KU4sY_UEavndBw

 

Glad to see you got it going right,,, good catch on the lose header bolt,,, is that PCV valve on the driver side rear just below where my brake booster vacuum is ???? been meaning to change mine but keep forgetting to pick one up,,, oh and thanks for the link i will check it out

 

Its on the drivers side, top of the valve cover towards the rear of the engine. Its under the rear of the upper intake.

 

CEL is back on with the same misfire on cylinder 4. I swapped to a backup coil pack I had in garage and still have the same problems. I changed plugs maybe 30,000 miles ago, but not the wires. So now I am waiting on Motorcraft plugs and wires from Rock Auto.

It's not a steady misfire. Its worse at idle with the engine cool to warm. Running, it smooths out and during acceleration and cruising. When I come to a stop, after a few seconds, when the cylinder temps drops it seems, you can feel the cylinder not fire a few times, then fire a few times, then not again...... Plug was clean looking when I did the injectors. I pulled the wires out and looked them over at the same time, and there wasn't any burnt or worn spots.

Can the computer tell a misfire for a certain cylinder if it is fuel related? Or is it reading info from the coil pack to tell if a plug is firing or not?

 

Have you double checked the hots and grounds going to that no. 4 misfiring plug injector ,,, i would try putting a test light from hot on battery to the right wire on injector plug connector and wiggle the wire ( maybe with help from friend) and watch test light close,, if no problem then change test light over to ground on battery and the other wire on injector and try the wiggle test again watching the test light close,,, if light stays light then no problem but if light blinks during wiggle test there ya go,,,, wiggle them good ,, push pull whatever just to make sure you do not have a intermeadirite open or short ,,, they can be hard to find ,, does not hurt to double check ( sorry could not remember how to spell intermeaderite LOL ) oh and maybe you should check the ground over good for tarnish and corrosion,,, it got to be something simple i would think

 

I'm pretty sure I can get a stethoscope to that #4 injector and listen to it tick. That might be easier than getting its plug off right now. That way with the engine running, I can match the stumble to the injector sound.

It smelled like it was running rich at idle this morning, but I didn't have the programmer plugged in to the read O2 sensors. I'm thinking I have fuel, but not spark now.

I'll let you know what I find with that and the test light.