Progress Thread Explorer intake install

sav22rem22

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Feb 6, 2020
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So I finally got around to installing a 96 explorer upper and lower on my 89 GT. I also upgrade to the 4 hole style 19 ib injectors. It was a long and painful process as it was my first time doing this and everything below the fuel rail had never been removed off of my car. The stupid fuel rail quick disconnects were a pain but I finally got those off and then had to put my entire body weight off the side of the car to pull the fuel rail off the old crusty injectors.

Once the fuel rail and injectors were all removed I removed the distributor and then all of the lower intake bolts and two studs. The bolts and studs on the very ends were very hard to remove as the threads were caked in thick black gunk. Covered the lifter valley and removed the 32 year old gasket over the course of like 6 hours and then finally reassembled with the proper torque sequence. Put it all back together and ran into an issue with the upper to lower bolts with some being too long. Very odd issue that I’ve yet to figure out.
Once the distributor was stabbed and everything was ready to go I cranked the car and checked for leaks and didn’t see any. The car started first try with no troubles. However I can hear a vacuum leak and got some smoke with my tester from under the upper intake. I also noticed the next day that there is a bit of fuel pooling to the left of injector 2. The injectors have brand new o rings and pintle caps and were lubed. All the fuel rail bolts are tight. Anyone have any suggestions about this? I’ll check it out once I do the retorque on the lower.

However it’s only been through one heat cycle and I’m too scared to run it due to the leaking fuel rail to injector seal. Should I go ahead and pull the upper and retorque and fix the leak all at the same time? Also anyone know why the bolts may be too long on my upper to lower? The four bolts up top are they all the same size? I’ll include some pictures later I’ve just been so consumed with this job
 
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HemiRick

I'd be looking at jacking under the house
Jun 28, 2020
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Memphis TN
Yes fix the fuel leak ASAP, the bolts maybe too long because they are meant to be used w a spacer between the upper and lower. I f I remember right the 2 bolts under the 5.0 plate are alittle bit shorter than the 2 on the ends.
 

rockyracoon

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Nov 23, 2005
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Sounds like the leaking injector didn't seat all the way into the rail. Try removing the rail to lower bolts and gently pushing down on the rail just above that injector. Do not under any circumstances run engine with the leak.
 
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sav22rem22

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Feb 6, 2020
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Yes fix the fuel leak ASAP, the bolts maybe too long because they are meant to be used w a spacer between the upper and lower. I f I remember right the 2 bolts under the 5.0 plate are alittle bit shorter than the 2 on the ends.
That could be a possibility. They're just a tiny bit too long and it’s only 2 of them that have the issue so I must’ve put them in the wrong place. It’s such a small amount you can’t even see the gap between the flange head and the intake
 

sav22rem22

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Feb 6, 2020
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Sounds like the leaking injector didn't seat all the way into the rail. Try removing the rail to lower bolts and gently pushing down on the rail just above that injector. Do not under any circumstances run engine with the leak.
Yeah I haven’t and thankfully I noticed the fuel pooling next to it. I was about to put it through it’s next heat cycle and that could’ve ended horribly. Tomorrow I’m going to pull the upper and get that fixed at the same time. Thanks for the input
 

sav22rem22

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Feb 6, 2020
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Well a little update on this thread. I pulled the upper off today which was a complete pain it was practically glued to the lower after only a few days and all I used was a cobra upper to lower gasket from LMR. Once I finally got that off I inspected under the upper intake for the vacuum leak and found the source. The hose that connects to the pcv T fitting finally kicked the bucket after over 30 years. Luckily I had some 3/8 fuel hose laying around and replaced that old hose.

I also figured out the fuel injector leaking problem. The passenger side front fuel rail bolt was loose. This is why it’s always important to double check your work. Thankfully I didn’t have to learn it the hard way but for anyone reading always double, even triple check your work and don’t rush anything like I did.

As for the too long bolt situation I haven’t figured that out yet. I did go back and get the long bolts from the original upper intake and they work perfect for the shorter ones under the plaque. As far as the two end ones I’m not sure what’s going on. In the mean time I’ll probably get a few washers to go on them until I can source some proper ones. They’re just barely barely too long. They practically touch the upper intake when all the way tight it’s just that they don’t clamp much. It’s unfortunate that the gasket was pretty much destroyed in the process because now I’ve got to wait even longer to get some more unless an auto parts store sells them
 
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foxbodybill89

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Jan 19, 2020
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The explorer intake bolts are slightly different lengths than the original, you may have to cut some bolts to a custom length or use all-thread and nuts on top. I did the all-thread route, you can just snug them into the lower intake then torque the nuts on top instead of risking stripping out the threaded holes in the lower intake when torquing.
 

sav22rem22

Active Member
Feb 6, 2020
195
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North Carolina
The explorer intake bolts are slightly different lengths than the original, you may have to cut some bolts to a custom length or use all-thread and nuts on top. I did the all-thread route, you can just snug them into the lower intake then torque the nuts on top instead of risking stripping out the threaded holes in the lower intake when torquing.
I was thinking about going that route. What length did you use for your threaded rod?
 

foxbodybill89

Member
Jan 19, 2020
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Set your intake on with whatever gaskets and spacers you are using, thread the rod all the way into the hole until it stops and mark it where you want to cut it, leave just enough sticking up to thread the nut on completely. I actually used chrome acorn nuts and cut the rod short enough they would tighten down and leave a nice finished look rather than leaving bare end of rod. I also used a dremel to slot the end of the rod after cutting it so I could screw them in and out with a screwdriver.
 

rockyracoon

Active Member
Nov 23, 2005
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I agree in regards to not ever having the fel pro gasket or any brand gasket stick to the lower. I've reused em numerous times without incident.
 

sav22rem22

Active Member
Feb 6, 2020
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sav22rem22

Active Member
Feb 6, 2020
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North Carolina
Well another update. Gaskets came in so I put it on and also fixed the bolt issue and torqued those to 12 ft ibs in a cross pattern then hooked everything back up and primed the key and checked for leaks and there weren’t any leaks at first. I started the car and it fired right up and ran great. Was a little smoky as it burned any liquids off.

I turned off the car after a few minutes of idling and checked for leaks again and of course the same injector was leaking. It’s leaking on the back side of the fuel rail where the injector protrudes out of the fuel rail hat. This is beginning to get very frustrating. I have a few theories on why this is happening. When I put the fuel rail back on after the install I got the fuel lines in a bind and they seem to be pulling on the rail. Could this have caused the injector to not seat correctly? I thought for sure when I found the loose fuel rail bolt that was it

Another theory I have is that my fuel pump (255Lph) is simply too much for my stock fuel system and may be causing the fuel pressure regulator to be not effective (as shown in pro m efi video). So now my final question is that if I have to replace the O-rings for whatever reason, will stock fox body injector O-rings work? I do have the explorer four hole style injector in the car which is why I’m asking.
 

nickyb

WAIT,you now have a pair?
10 Year Member
Apr 3, 2009
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It's not the fuel pump.Just order o rings for the exploder injectors.
 
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Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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The o rings are all the same.

if you have one of the original injectors you can swap it in to test. The explorer injectors are 19# like the originals so it won’t hurt to swap. The explorer spray pattern is better but this is really to test.

a 255 on stock fuel lines might bump pressure slightly. Would need to test with a Guage to verify. This is due to the increased flow meeting resistance in narrow lines. All speculative until you put a gusge on it.
 

HemiRick

I'd be looking at jacking under the house
Jun 28, 2020
725
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Memphis TN
Its possible for the fuel rail cup to bite off a small piece of the o ring, I had it happen to me, did you inspect the upper o-ring on that injector?
 

sav22rem22

Active Member
Feb 6, 2020
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North Carolina
Its possible for the fuel rail cup to bite off a small piece of the o ring, I had it happen to me, did you inspect the upper o-ring on that injector?
I haven't yet as the weather sucks pretty bad right now but I'm going to check tomorrow. I think this might be what happened as I wasn't as gentle as I should've been installing them the first time. My fault for rushing
 

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
36,114
12,036
224
Massachusetts
Petroleum jelly should be fine. I actually think the o rings used in injectors is safe for use with petroleum products but never confirmed it.

in general, basic everyday o rings will swell or disintegrate if you use oil based lubes. Rubber seals and o rings used in engines are made to handke oil. I just never confirmed that injector o rings are the same. As a default, I always use the above lube on oil