PHH and Knock Sensor visual verification

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hisandhers80s

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Madison, MS
I have removed both the upper and lower intake manifolds. When removing the lower manifold it slipped down and broke a connector to what I think is the rear Knock Sensor which is right below what I think is the Pesky Heater Hose. I have consulted the FSM, posts on Mud and several YouTube videos. I just want to verify these are indeed the rear knock sensor and PHH before I order parts. This is on a 4/1994 FZJ80 with a 1FZFE.


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I just bought this 80 and my baseline/while you’re in there is wild. I am going to start a build thread soon just to detail it. And you are right, it looks terrible, just like every hose, belt, and vacuum line on this truck.
 
Change the other two coolant hoses as well, known as the throttle body bypass hoses. The one right next to the pesky in your photo which feeds throttle body and the other one coming off the throttle body; there is a third one down the line but that one is easy
 
I have all three hoses arriving tomorrow via FedEx. Replacing every single coolant hose on the truck along with all vacuum hoses.
 
Quick tips:

Replace or at least sand, prime, and paint the pipe connected to the PHH.

If you buy a new phh-pipe assembly, toss the new OEM hose that comes attached (because it's wimpy which is why IMO they all rupture) and replace it with GATES GREENSTRIPE 5/8" heater hose but still sand prime and paint the new pipe because the original paint is super thin.

Use OEM clamps, or BREESE Constant torque clamps or GATES Power Grip clamps (bands). Never use those sheit worm screw type clamps.

You won't have to touch the PHH again for 20-30 years.
 
Should I use high temp engine paint and primer or what is the recommended paint and primer for this application?
 
You're on the right track with the knock sensor and hoses...and since you mention baseline work, while you are in there, check your injector harness plugs at each injector for being brittle/broken. These fail at this age and the 5-6 cylinders in the back are especially prone to this being back by the EGR pipework and extra heat. I also found a few other sketchy connector plugs on mine which can all be easily sourced and replaced now while you are apart and they are easy to get to.

It's also prime time for some EGR "maintenance and testing" if you so choose to address it.
 
CrabCake said:
You're on the right track with the knock sensor and hoses...and since you mention baseline work, while you are in there, check your injector harness plugs at each injector for being brittle/broken. These fail at this age and the 5-6 cylinders in the back are especially prone to this being back by the EGR pipework and extra heat. I also found a few other sketchy connector plugs on mine which can all be easily sourced and replaced now while you are apart and they are easy to get to.

It's also prime time for some EGR "maintenance and testing" if you so choose to address it.
Click to expand...
I have a brand-new EGR valve and Modulator, as well as the metal hose that connects them to the block. I was going to delete it, but my parent company is based in Arizona, and I've heard they have emissions testing. So, I don't want to do something that will prevent me from being able to register there if, by chance, I get moved out there for a promotion.
 
hisandhers80s said:
I have a brand-new EGR valve and Modulator, as well as the metal hose that connects them to the block. I was going to delete it, but my parent company is based in Arizona, and I've heard they have emissions testing. So, I don't want to do something that will prevent me from being able to register there if, by chance, I get moved out there for a promotion.
Click to expand...
AZ emissions is only around Phoenix and Tucson. Not the entire state. Of course that is also where most businesses are located.
Northern cities don't have emissions requirements: Flagstaff, Sedona, Prescott, Payson . . .

ADEQ VEC Locator

ADEQ Vehicle Emissions Control interactive map.
mygis.azdeq.gov
 
doc_random said:
AZ emissions is only around Phoenix and Tucson. Not the entire state. Of course that is also where most businesses are located.
Northern cities don't have emissions requirements: Flagstaff, Sedona, Prescott, Payson . . .

ADEQ VEC Locator

ADEQ Vehicle Emissions Control interactive map.
mygis.azdeq.gov
Click to expand...
The company I work for is based in Phoenix.
 
So, Phoenix has emissions testing, but being Full Time 4-Wheel Drive, that means 1995+ OBD2 compliance testing which is plug-in, not inspection.

What I'm getting at is that if you can complete the EGR delete without drawing OBD2 error codes, you'd probably be fine testing and passing in Maricopa County, where Phoenix is located.

When I test, they never even open the hood.
 
LongDuck said:
So, Phoenix has emissions testing, but being Full Time 4-Wheel Drive, that means 1995+ OBD2 compliance testing which is plug-in, not inspection.

What I'm getting at is that if you can complete the EGR delete without drawing OBD2 error codes, you'd probably be fine testing and passing in Maricopa County, where Phoenix is located.

When I test, they never even open the hood.
Click to expand...
I have an OBD1 4/1994 unfortunately. Is there a cheater way around on the 1994?
 
I don't know how the test program runs on pre-OBD2 4×4s, but it's certainly NOT going on the rollers. Maybe a 3FE owner in Phoenix can help,
 
For priming and painting water pipes in the heater circuit you can use just about any engine enamel paint (and primer) that is good up to say 250'F or higher. I used SprayMax 2k Epoxy primer and 2k Hot Rod black (Satin/Semi-gloss black similar to the original color) and it's holding up.

FWIW most 2k paints in a rattle can (paint and hardener in same can) have to be used up within 24 hours of mixing the two components. IME it helps to plan out the project ahead of time, ie: get a bunch of parts clean, sanded, ready to hang up somewhere so you can paint them all at the same time.
 
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hisandhers80s said:
I have removed both the upper and lower intake manifolds. When removing the lower manifold it slipped down and broke a connector to what I think is the rear Knock Sensor which is right below what I think is the Pesky Heater Hose. I have consulted the FSM, posts on Mud and several YouTube videos. I just want to verify these are indeed the rear knock sensor and PHH before I order parts. This is on a 4/1994 FZJ80 with a 1FZFE.


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Hey Kernal, I am wanting to replace my PHH. What parts did you end up using? -thanks
 
Do you mean for the PHH? On of my 80's I used a section of 5/8" Gates GreenStripe heater hose and Breese constant torque clamps, still holding
after15+ years.

On my other 80 I went a bit deeper, bought a new PHH-hose assembly but removed the factory clamp and OEM hose, sanded the new PHH pipe, primed and painted it using 2K Epoxy primer and top coat. Then installed a section of Gates GreenStripe heater hose.
For clamps I used two GATES PowerGrip hose "clamps" which are actually a type of heat shrinkable thermoplastic bands which you apply heat to from a heat gun and they shrink down forming a good concentric seal. The Breese clamps work well also.

While you're up in there is a good time to also replace the bypass hose that runs up to the Throttle Body. For that you'll need the OEM formed
hose and at least one OEM clamp (or two if you use one on the bottom end instead of something else.

The advantage of using OEM hose clamps is when working in a cramped area the OEM clamps come with a clip that holds them open
so you just have to get the clamp in place then flick the little clip off the clamp and it shuts, no fiddling with pliers on the clamp.
 
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