914 - SHO Verify Vaccum hoses

[3d914]

Found this reference in the SHO Motor book to a purge canister hose (A), but it doesn't describe the other ends location.

Looks to be the same hose shown in SHO Phoenix Project photo (circled in yellow). Where does the other end connect?

 

[3d914]

Also, what is feeding the IAC vacuum? I see where the outlet splits and connects to the intake runner control valves, but can't identify the feed line source. It's possible I may have plugged it when I cleaned up the purge canister - thinking it was EGR or something.

 

[3d914]

Another ?
SHO Phoenix Project (page 2) mentions a grounding strap that connects to one of the surge canister mounting brackets. Is this only needed for the DIS, or is there another purpose for grounding the canister?

 

[Ishodu]

As far as I know its only for the DIS. I moved mine to the cross over tube mounting bolt if it means anything to you.

 

[Off Road SHO]

The purge cannister is where all the fumes from the SHO's gas tank were stored in a a mixture of activated carbon. If you don't have this type of modern pollution control on the 914 (highly unlikely), I would plug off that port in the throttle body.

The IAC (Idle Air Control) is not fed vacuum. It's an electric air valve that goes to full open whenever you press the gas pedal and doesn't close down its airflow untill commanded by the computer when you lift your right foot completely off ( when the throttle position sensor tells the computer that you have lifted).

The Intake Manifold Runner Control (IMRC) get its supply of vacuum from a little ****** on the (now) passenger side Surge Tank.

Tom

 

[hawkeye18]

http://dl.dropbox.com/u/43901459/SHO_Engine_Book.pdf

Just download that. It'll make your life a lot easier. It's where I've gotten most of the answers I've given you previously.

However, as far as the IMRC goes, look at this. Be aware that this book calls the IMRC system the I[ntake]AC, and the I[dle]AC the ISC. It's somewhat confusing. Anyway -



I think the canister purge question has been adequately answered.

 

[3d914]

The purge cannister is where all the fumes from the SHO's gas tank were stored in a a mixture of activated carbon. If you don't have this type of modern pollution control on the 914 (highly unlikely), I would plug off that port in the throttle body.

The 914 routed fumes back to the tank in the return line.

The Intake Manifold Runner Control (IMRC) get its supply of vacuum from a little ****** on the (now) passenger side Surge Tank.

Tom

I think I dissed that ****** when I cleaned up the surge canister. Can I just T off the small one that feeds the Fuel Press Reg up front?

 

[hawkeye18]

I think I dissed that ****** when I cleaned up the surge canister. Can I just T off the small one that feeds the Fuel Press Reg up front?

Yup. Any source of vacuum will do. The important part is that vacuum canister that stores a reserve of vacuum (and is also a check valve). Without it, at full throttle the IMRC won't have enough vacuum to activate!

 

[Off Road SHO]

Without it, at full throttle the IMRC won't have enough vacuum to activate!

He meant to say de-activate. The secondaries are activated by springs, and de-activated by vacuum.

What did you do with that little ******? Unless you welded it closed, there is enough aluminum in that place to drill, tap and insert a hose barb fitting.

Also, there is a forwards and a backwards in that canister because of the one way valve within. The a white dot and a yellow-ish dot next to each ****** on the one side of that canister.


Tom

 

[pjtoledo]

Found this reference in the SHO Motor book to a purge canister hose (A), but it doesn't describe the other ends location.

Looks to be the same hose shown in SHO Phoenix Project photo (circled in yellow). Where does the other end connect?

MAP sensor ??? eh, just a small TYPO, nothing to worry about.

 

[intimdatr]

MAP sensor ??? eh, just a small TYPO, nothing to worry about.

Wow. Thats an interesting Typo.

 

[Off Road SHO]

Gerard,

The other end of that hose goes to the electrically operated air valve that is commanded to open every once in a while by the PCM. When the valve is open, it lets the fumes that have been building up in the charcoal canister, be sucked into the engine. If you're not going to have a charcoal canister, you can plug that opening in the throttle body.

Tom

 

[jelloslug]

Gerard,

The other end of that hose goes to the electrically operated air valve that is commanded to open every once in a while by the PCM. When the valve is open, it lets the fumes that have been building up in the charcoal canister, be sucked into the engine. If you're not going to have a charcoal canister, you can plug that opening in the throttle body.

Tom

Or just remove it completely.

 

[hawkeye18]

MAP sensor ??? eh, just a small TYPO, nothing to worry about.

Not necessarily a typo - this book was an instructional manual from '88, and Ford hadn't really standardized the acronyms yet. Many of the sensors in our SHOs have different names in this book - the IAC is called the ISC, the MAF is called the MAP, the IMRC is called the IAC, and a few other ones are named differently as well. It's just something you have to kind of translate in your head.

 

[3d914]

What did you do with that little ******? Unless you welded it closed, there is enough aluminum in that place to drill, tap and insert a hose barb fitting.

Also, there is a forwards and a backwards in that canister because of the one way valve within. The a white dot and a yellow-ish dot next to each ****** on the one side of that canister.

Tom

Tom,

Its been welded over. And I also got rid of the mounting pads for the assembly. I plan to mount it to the read firewall next to the engine.

I also ran the supply line over to a T in the FPR hose. I might need a new vacuum canister for the IMRC. The outer plastic housing looks like someone laid a soldering iron up against it. Appears to be air-tight though. I'll test it this weekend.

 

[Off Road SHO]

Shake it a little. If you hear a rattle sound, the one way valve on the inside has broken off and it wont work.

If the soldering has made it a little thin, just throw some epoxy coat over it. You can also make your own storage container with an external backflow preventer. Just keep it close to the source of vacuum; the same rules of resistance = diameter x distance applies to vacuum as well as positive pressure.

Tom