97 4.0 Has had the two lean codes & last week misfire on 3&6 popped up. Cleared the codes ran it again. The same two lean codes but this time random misfire. So I'm going to try do the fuel rail gasket this weekend. I not positive it's the gasket but with the TSB out on it, it's likely the cause. I can't find any vacuum leaks or anything. I have a few question before I dig into this thing.

1. Once I get the plenum off & the gasket doesn't appear to be sucked in should I still replace it?
2. After removing the studs from the fuel rail will the injectors separate from the rail or the intake?
3. Should I replace the injector orings? How can I tell if they need to be replaced? If so all of them or just the ones that are accessible?
4. Any special tools besides the torx & torque wrench?

I like to be prepared & know what to expect before I start digging in this thing. I read it's not that hard just a little time consuming maybe. If it's the gasket I'll be sure to take a pic & post it. If you have any other suggestion or tips I'm all ears. Thanks!

 

Question 1: yes, replace it anyway cause it's not as soft as a new gasket and won't seal as well, plus it may break when you take it apart. They get brittle with age. You should be able to purchase just the upper intake gaskets separate from the lower gasket.
Question 2:yes the injectors will come out of the rail and the intake once the rail is loose. You may want to use a little brush and a vacuum cleaner to suck up dirt or other debris around the injectors where they go into the manifold so that dirt won't go down the hole as the injector gets pulled out.
Question 3: yes you could replace the o-rings since you're in there and they aren't very expensive. Check them for being soft and free of cracks or cuts. If you find a cut on an o-ring, check around the rail or manifold hole it came from. There may be a burr or sharp edge it got cut on, that should be removed so it won't cut the new one as it goes in. You could remove it with a small round file with the help of the vacuum to keep the pieces out of the manifold. When you put them back together in the rail and manifold put a little smear of engine oil around the o-rings to help them go together easier. You could seat all the injectors in the manifold first, then lower the rail into place just over two at one end, then seat it on those two and work your way to the other end.
Question 4: only other tool besides the vacuum cleaner would be a small pick kind of tool to help get the o-rings off the injectors. If you use the pick to remove the o-ring, try not to gouge the body of the injector. Not sure if your injectors are plastic where the o-ring sits. If it gets gouged it could leak a bit. Not sure what info or manual you have but there is a torque sequence pattern on the fuel rail & upper plenum that goes from the center outward both directions. Bolts on my 4.0 are external torx #7 socket. Take your time and it should go pretty easy.

 

Thanks for the tips. Went to ford this morning the gaskets will be here in the morning. I have the upper plenum loose but it looks like the egr valve is holding it. Do I need to unhook the egr? How do I unhook it? Does it come loose from the plenum or Do I need to unbolt it at the bottom? Thanks!

 

Not a good day. I button everything back up. Got frustrated. rockledge has a good write up on the intake gasket that I read, but no were did I see anything about disconnecting egr. I even read the Ford shop manual it doesn't mention it either. Looking at pictures online were people have done it show the egr tube coming out of the intake. To top it off I called the dealer & asked if they would look at it & change the gasket. They don't work on anything under 2000. They would charge me $95 to look at it to see whats wrong. I thought about it but,The upper gaskets pretty much need to be changed since I already busted them loose. So I need to find a shop or just do it myself. I just moved up here because I had to go on Dialysis. So I don't know of a shop I trust. Having a treatment today & feeling drained probably didn't help matters, but I know I need to get it done before this cold front. Between feeling like crap & looking for my tools & the egr I got frustrated & buttoned it back up. If anyone knows about the egr that would be great. Do I need to unbolt it at the egr? How does the tube come out of the intake like in the pic I seen on line would be great. At this point it looks like I will be unhooking everything again & trying to do it myself.

 

Sorry it's not cooperating with you. No EGR like that on mine. Might be best to unbolt the egr and pull it with the upper plenum. You'll probably need a new gasket for that too. I hope you're feeling better soon. Maybe Rocklegde can add some tips for you.

 

Thanks Rangerman for the kind words. I go to Dialysis MWF, go in the morning & off for two days. One thing I didn't want to do is go on Dialysis. It's just something I have to do know to live. Anyway I got the intake off. If rocklegs has any tips still would like to hear them. Anyway, The egr tube popped out of the intake just had to force it a little. I didn't change the fuel rail gasket, because it wasn't sucked in. So I took a chance leaving it alone. The three intake o-rings were hard a rock, replaced those. Buttoned it up & Drove it, it has no power now. Takes along time to shift & seems to shift hard & a rough idle, different DTC's though. So far no P0171 or P0174 lean codes, Now have P1151 & P0153. You think Bank2 senor1 is bad? Here is freeze frame data for P1151. Thanks!

Closed loop
Cal load 78.8 %
ECT 145
STFT B1 -2.3 %
LTFT B1 0 %
STFT B2 44.5 %
LTFT B2 0 %
rpm 1567
Veh speed 32 mph