Fuel Injection System

[Donut20]

Hey guys,
I have a '94 Ranger XLT 4.0 V6. The check engine light came on and it was sluggish to accelerate but held at 35/40 mph. Had to learn how to diagnose a vehicle this old but got a paperclip and was able to figure it out. I got a few codes but 157 kept cycling so I determined it was the MAF sensor and swapped it. Cleared the code and It ran well for about 30 miles (not the only problem, shift solenoid is also going) but started to bog down and stall out even and check engine light came back on. It wouldn't run with the MAF sensor plugged in, so I unplugged the MAF sensor and it started and I limped home. Now I'm looking over the area and see a break in this line (red arrows). I follow it and it feeds into the air box (second pic). I do not know what this black canister is for/ or called (blue arrow). I am convinced I should replace these lines I just would like to know the name/function of this particular part of the system and am having a hard time figuring it out. I am going to replace the fuel filter since it may well be original. I have been replacing things as I go since I sold my '97 Isuzu Hombre for it and fortunately am not too deep into it, but don't have the means to take it to my mechanic all the time (he's always really helpful with any questions though). I am not a mechanic just a humble DIY guy hungry for information, any help is appreciated.

 

[Eddo Rogue]

Those are vacuum lines, mine were brittle and broke as well. I ordered a bunch of various rolls of vacuum hose and hard line and replaced most of them. The only tool you will need is something to cut with and maybe some pliers lol.

Oh also if you bought a duralast or dorman at an autozone type store, then you may have gotten a bad MAF off the bat.

I stopped buying stuff from regular auto parts stores because half the time it doesnt work right or not at all. Stick with Motorcraft or a factory replacement brand like Denso for electrical stuff.

 

[RonD]

The blue line is on the Vacuum Reservoir, small plastic cylinder, it stores vacuum for use in the Cab for the air direction vents, i.e. defrost, panel, floor
Defrost is the default, no vacuum present, air direction

The hard plastic vacuum hoses can be repaired or replaced by regular rubber vacuum hoses, the plastic lines are just cheaper when making thousands of cars

Vacuum leaks will cause running uses

The second picture is vacuum connection for the warm air by-pass used on Cold start only
Inside the air cleaner is the thermal valve, it detects air temp mechanically, no power needed
It will send vacuum to the Cold Air Intake tube that will open a valve that causes the engine to suck in air from around the exhaust manifold until engine warms up a bit, its an emissions system, the faster any engine warms up the better, as far as lower emissions
This pre-heated air setup is often missing after an engine has been worked on a few times, lol
There would be a thin metal "air chamber" clamped on to the passenger side exhaust manifold
Then a larger flexible metal tube(like Dryer Duct) running from this air chamber to the valve on the cold air intake tube

It wouldn't cause running issues either way, working or not

 

[Donut20]

Awesome thank you! I was concerned that it could have been faulty off the bat :/ I'm digging into how the how they function and it's pretty interesting. I also hear a "hissing" after shutting off the engine so I assume there is a break in another line as well.

 

[Donut20]

That's awesome info thank you! Bummer that I'll have to keep troubleshooting but I'll replace these hoses since they're so brittle.

 

[Kira]

Quarter century rubber.....coolant hoses too.
Can a 26 YO vacuum reservoir crack/leak? Old plastic vacuum trees in the intake man.
A wise man said a bad/neglected PCV system can serve as a vacuum leak. Applies here?