97 Explorer XLT V8 Runs Rough poor power/mileage!

[l2sail]

Hello we have a 97 XLT with a V8, 4WD with the following symptoms:

-Idles rough (extremely)
-Gets poor fuel mileage ( normally 18-20 highway, now 12-15!)
-Can pull spark plug wire from 3 different cylinders (I think its 3,5 and 8) and still runs the same (no drop in engine sound/rpm)
-Pulling the plugs from these cylinders shows they are wet and thus getting fuel.

Whats been done, its been brought to two garages (1 a ford dealer) and the diagnostic test at both said to replace the #8 fuel injector or the injector wiring harness or the PCM. (Gave a PCM selftest fail code)

Garage one:
Replaced spark plugs and spark plug wires
cleaned the fuel rails (found some rust residue)
Replaced the #8 injector
Tested the injector cablling
Tested compression (all good and level)
Tested Vacuum, all good
Replaced the ignition packs (both)
Tested fuel pressure (Good)

Garage two (Ford Dealership)
Ran diag and it said to replace the PCM which they did and it didnt correct issue.
They they recommend to replace the injector on #8 or the wiring (same as 1st garage)

I know some of the codes the diag gave and I can add them if helpful, I just dont have them with me now.

So at this point we are at a loss, we dont want to keep soaking money into the vehicle, if I dont get any other suggestions we will try replacing the injector in # 8 again and then the wiring harness but I doubt that will fix it, the number 1 garage is not a dealer but specializes in fords. Also the injector replaced was from Ford directly, not an aftermarket unit.

The 1st garage suggests the problem is a HARD engine problem that the computer doesnt have sensors see/diagnose and with the inputs it is getting is adjusting things it can contol, IE timing, fuel delivery and so on to try and correct the issue. IE possibly internal timing chain issue, sticky valves (not closing quick enough when engine running)

Any and all suggestions will be greatly appreciated.

THank You

~ Phil Morneault

[stv840]

give me codes

[Truck]

What level of gas are you using? I'd be hesitant to get the thing addicted to High-Test, but I would suggest changing gas stations and seeing if that solves the problem. I think with the price of gas being what it is, that some shops are substituting with water to avoid shortages.