ljobbins

While working on my engine I broke this line. It looks like a vacuum line but not sure. It is an 88 4.0 engine. The line goes from above the engine attached to some squarish thing attached to the body to a rubber thing on the side of the throttle body (Sorry for being so technical). The line broke off inside of the rubber part on the throttle body. I was wondering how the line attaches to that rubber thing? When I replace it is it just push into the rubber thing? do I need to take that rubber thing out to get the broken piece? What is the line for? Is it stocked anywhere? It seems like a small enough simple enough repair, but for some reason they seem to give me the most trouble. Thanks for any help.

Travis88XJ

That is the MAP sensor vacuum line. For mine it is just pushed into that rubber grommet and I would take it off to get the broken piece out. Basically the MAP sensor (small box near top center of the firewall) tells the computer how much vacuum is present and adjusts how much fuel it needs. As far as being stocked anywhere I wouldn't know but cruiser or any one of the other Renix engine experts should have more info on this.

DFlintstone

Edit; I almost forgot. I hear any manifold vacuum to the MAP is OK. (Like, "T" off that big line rear of the TB). Of course you need to plug the hole in the rubber plug. I kept mine as designed.

Yea, like Trav says, it's the MAP tube and very important. I actually used a tiny left hand thread screw extractor to get my broken piece out. Really though, any tiny screw you could get to get a grab in it might work. The rubber plug comes out OK. (the first time I tried I thought maybe it didn't). I'm not near a store. What I did was to keep the sections if rigid tube that were still OK, and carefully heat and bend a couple pieces, (very careful there, the tube will melt), then found some small vacuum line that would fit over that and spliced my tube back together. Was not a super fit so I put RTV silicone on the rigid only . Reason being it's crucial nothing blocks that little tube.

Possibly ACE or somebody sells small rigid tubing that can stand under-hood temps, Idk.

cruiser54

This may help put things into perspective.

That line is no longer available.

cruiser54

This is what I did:

Removed the Renix TB. Found I could tap the vacuum port for the MAP sensor line 1/8 NPT and thread a plug right in. No drilling required. I put a vacuum fitting into the intake manifold where the IAT was before I relocated it to the air box. Using spare plastic line from previous vacuum harness replacements and a hair dryer, I formed a new pipe from the intake fitting to the MAP.

ljobbins

What is the IAT mod you are taking about Cruiser?
And thanks for the help guys.

cruiser54

I thought I did a write-up but can't find it.

http://www.angelfire.com/my/fan/IAT_sensor.html

ljobbins

cool thanks