Need help identifying what's not stock in my engine bay

[hgeranium]

Hi, first time poster and first time Jeeper, so apologies if the formatting is odd.

 

This is the hacked up engine bay of my 1988 Comanche Eliminator 4.0. I've had this truck since 2022. Comparing it to an engine bay from the reference pic thread, there are a lot of quirks that I know are not stock. It's such a jumbled mess of wires, lines and hoses. There is only so much detail that I can gather from the single overhead picture from that thread, so any more detailed reference pics matching the ones I've submitted would be great. 

 

My main concern is the vacuum lines but please feel free to point out any other oddities if you spot them. The organization/location/routing of the lines are completely different from the vacuum line reference pics. I no longer have the traditional vacuum harness (or at least the bracket connecting the front and rear harness next to the FPR). Also, I notice that there is a HO airbox on my non-HO 4.0. I disconnected the CCV hose from the airbox because I was tired of that oil on my filter and temporarily have it going into a 'catch can'.

 

Mainly, I just need help having certain things pointed out that are different or outright wrong and if they need to be fixed. I understand the previous owner(s) did a few QOL changes like adding the 97+ electric fan but the HO air box and the lack of a traditional vacuum harness really stump me. It runs great. No major vacuum leaks, but the way that the lines are all haphazardly spread around the engine bay makes it hard to compare it to a stock diagram, so I have no idea if the lines going in and out of that vacuum reservoir are routed correctly, or if it even matters.

 

I wrench on my own vehicle but I would still consider myself a novice with only ~3 years of experience working on this motor. I can only get so familiar with it when this is my only point of reference lol. Also please excuse the dirty engine bay, I'll detail it someday when the organization of the bay is a little neater.

 

Any guidance helps! Thank you. And of course I can send more pictures if needed.

[fiatslug87]

I would replace all the vacuum harness lines. Yours has cruise control, but look through this thread.

 

 

[hgeranium]

8 minutes ago, fiatslug87 said:

I would replace all the vacuum harness lines. Yours has cruise control, but look through this thread.

 

 

That is a very helpful thread! Thank you. What do you think about the HO air box being there? Do you think it's necessary to get the correct one for the right hookups, or could I make the HO one work?

[JZLAJeep]

46 minutes ago, hgeranium said:

That is a very helpful thread! Thank you. What do you think about the HO air box being there? Do you think it's necessary to get the correct one for the right hookups, or could I make the HO one work?

We intentionally put in a HO air box and capped a bunch of vacuum lines so it should work fine.

 

That's an interesting location for the vacuum can. That is supposed to sit inside the front bumper on the passenger side. One of my sons once deadpanned when we had a bumper off that it must be the blinker fluid reservoir. 

[hgeranium]

9 minutes ago, JZLAJeep said:

We intentionally put in a HO air box and capped a bunch of vacuum lines so it should work fine.

 

That's an interesting location for the vacuum can. That is supposed to sit inside the front bumper on the passenger side. One of my sons once deadpanned when we had a bumper off that it must be the blinker fluid reservoir. 

Yeah, at some point when somebody put the bullbar on this Comanche, they relocated it to just lie there in that mess of wires lol. I haven't messed with it because I heard leaving it in the bumper was a common failure point anyways iirc.

 

Which lines did you cap off? (sorry if that's a dumb question, just want to be sure) And do you happen to know what purpose putting in the HO air box is? I'm mostly worried about having to hack up a brand new vacuum harness trying to make it work with this air box.

[JZLAJeep]

6 minutes ago, hgeranium said:

Yeah, at some point when somebody put the bullbar on this Comanche, they relocated it to just lie there in that mess of wires lol. I haven't messed with it because I heard leaving it in the bumper was a common failure point anyways iirc.

 

Which lines did you cap off? (sorry if that's a dumb question, just want to be sure) And do you happen to know what purpose putting in the HO air box is? I'm mostly worried about having to hack up a brand new vacuum harness trying to make it work with this air box.

We pulled off everything but the line to the PCV (that you've already disconnected) and the line to the canister (on a 96+ this line is gone too). We removed the EGR, The vacuum motor came out when we swapped the boxes, and we must have capped the line to "vacuum fitting." In short, all the skinny lines to the air box in the diagram are gone. Didn't lose any function because the lines and connections were so brittle and poorly connected that they weren't doing anything anyway. Just making it like the newer 4.0s.  

 

I've attached a photo of what our engine bay looked like back in December (looks a little different now) with the HO air box.

[hgeranium]

8 minutes ago, JZLAJeep said:

We pulled off everything but the line to the PCV (that you've already disconnected) and the line to the canister (on a 96+ this line is gone too). We removed the EGR, The vacuum motor came out when we swapped the boxes, and we must have capped the line to "vacuum fitting." In short, all the skinny lines to the air box in the diagram are gone. Didn't lose any function because the lines and connections were so brittle and poorly connected that they weren't doing anything anyway. Just making it like the newer 4.0s.  

 

I've attached a photo of what our engine bay looked like back in December (looks a little different now) with the HO air box.

Thank you so much!

[llhat]

regarding your catch can... and the removal of the hose from the airbox...   you need to get some type of filter on that empty hose connection,

you are bringing in unfiltered air to the engine ( note this fitting is 'above' the air filter)

 

Look inside an early 70's  GM air filter,  inside the housing is a filter assembly that pokes thru the housing and connects to the valve cover via tubing...

one of those "could" serve as a filter if you do not reconnect the front fitting on the 4.0 valve cover to the air box... 

Looks like you've got your work cut out for ya....... 

 

 

[JZLAJeep]

7 minutes ago, llhat said:

regarding your catch can... and the removal of the hose from the airbox...   you need to get some type of filter on that empty hose connection,

you are bringing in unfiltered air to the engine ( note this fitting is 'above' the air filter)

This reminds me of Cruiser54's tip for addressing the oil blowback through the valve cover. 

 

[hgeranium]

Just now, JZLAJeep said:

This reminds me of Cruiser54's tip for addressing the oil blowback through the valve cover. 

 

Yep, that's on my to-do list next time I do my VCG.

[hgeranium]

9 minutes ago, llhat said:

regarding your catch can... and the removal of the hose from the airbox...   you need to get some type of filter on that empty hose connection,

you are bringing in unfiltered air to the engine ( note this fitting is 'above' the air filter)

 

Look inside an early 70's  GM air filter,  inside the housing is a filter assembly that pokes thru the housing and connects to the valve cover via tubing...

one of those "could" serve as a filter if you do not reconnect the front fitting on the 4.0 valve cover to the air box... 

Looks like you've got your work cut out for ya....... 

 

 

I actually had that hole covered up right up until I took those pictures (to replace the tape). I've had it covered up with tape and haven't had any issues (yet :p). I'm sure I could get a more solid solution (block-off plate etc.) but as I said, purely temporary. Thanks for the input though! If I end up keeping the HO box I'll remember this