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Topic: Explorer intake on modded '87 5.0 SO? (Read 911 times) previous topic - next topic

Explorer intake on modded '87 5.0 SO?

My engine tends to run a little rich and idles rough, so I'm wondering if moving to an Explorer intake might help matters a bit. Currently I have the following:

19# injectors
65mm TB + EGR spacer
AFPR
aftermarket cam (don't know what...maybe '86 HO cam?)
Stock 5.0 upper ground out to match TB inner diameter

I don't think I should need one, but who knows what the inside of my upper intake looks like, I figure it can't be flowing nearly as well as one made for the TB would. My mechanic neighbor is playing with it, he thinks there's a vacuum leak somewhere (which would make it run rich anyway) so the first order of business is to nail that down, but I figure it doesn't hurt to ask in case that doesn't resolve the problem. Everything else is stock (heads, lower intake, exhaust, etc.). Plugs, cap, rotor, coil are all new, 9mm wires are in good shape, etc.
[SIGPIC][/SIGPIC]
5.0L Speed density
Explorer intake
'92 Mustang GT cam
GT-40 racing heads
Unequal length headers
Custom-made duals
19# injectors
65mm TB
AFPR
T/C header panel
11" brake upgrade
T/C rear sway bar
Electrical mods: too many to list :D

Explorer intake on modded '87 5.0 SO?

Reply #1
Are you sure that it isn't the 19# injectors with a stock SO computer? Stock injectors on a SO motor are 14#'s and this would make a difference. Maybe if you were using the 5.0 HO speed density mustang computer.....Plus with a cam that you have no idea what it is. What firing order does the camshaft have? there is a difference between the HO and the SO cams. If you have all the HO stuff on the motor, try an HO speed density computer. That may fix all the issues.

If it was running fine for years with this combination and then all the sudden now it's running like , check for vacuum leaks, if none are found, check the fuel pressure, check for codes, check the MAP sensor, check the computer....kinda in that order.

Hope this helps

Explorer intake on modded '87 5.0 SO?

Reply #2
If you do decide to go with an Explorer intake, I happen to have one laying around that I'd like to get rid of...and you know I offer installation services...lol.

Good luck,
Don
Project 3G: Grandpa Grocery Getter-'85 Crown Vic LTD 2-door, 351W with heavily ported/polished GT40 heads, heavily ported/polished Typhoon Power Plus upper & lower intake, Comp Cams 265DEH retarded 1*, FAST EZ-EFI, HD T5, 8.8" 3.73 trac lock with extra clutches, 3G alt. swap, '99 CVPI front brakes, '09 CVPI rear disc brakes, '00 CVPI booster&m/c + wilwood adj prop valve.

Parted & Gone-'88 T-bird Sport, 351W swap, ported GT40 heads

Explorer intake on modded '87 5.0 SO?

Reply #3
The intake will not cause a rough idle, and isn't going to cause a rich condition at cruse... If you had good aftermarket heads, exahust etc, maybe could cause a rich condition at WOT...

Explorer intake on modded '87 5.0 SO?

Reply #4
Does the cam you are running have a 1-3-7-2-6-5-4-8 firing order? If so it has a HO/351 firing order and is causing a twofold problem with the stock T-bird SO EEC:
1. The injectors are firing at the wrong time as they are set to fire to the SO cam's 1-5-4-2-6-3-7-8 firing order.
2. The SO computer can't handle the 19 lb/hr injectors so the car is running rich.

I bet if you change to a HO SD computer from a 87-88 Mustang or 87-92 Mark VII I bet that your problems will go away ;)
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Explorer intake on modded '87 5.0 SO?

Reply #5
I don't know about the firing order, but would the car even run if the injectors were firing at the wrong time? When the RPM's get up to 900 or so everything smooths out and the car runs fine.
[SIGPIC][/SIGPIC]
5.0L Speed density
Explorer intake
'92 Mustang GT cam
GT-40 racing heads
Unequal length headers
Custom-made duals
19# injectors
65mm TB
AFPR
T/C header panel
11" brake upgrade
T/C rear sway bar
Electrical mods: too many to list :D

 

Explorer intake on modded '87 5.0 SO?

Reply #6
Quote from: Quietleaf;258773
I don't know about the firing order, but would the car even run if the injectors were firing at the wrong time? When the RPM's get up to 900 or so everything smooths out and the car runs fine.


It'll run but it will idle funky and run py at high rpms. Are you running 19s with the stock T-bird computer? If so that is what's causing the rich condition.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.