Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - Gen 1 Insight

Two weekends ago, I cleaned the EGR passages plate. That went well. In doing so, I found the steel tube connector for the vacuum hose that powers the fuel pressure regulator. It was rusted to the point of leaking vacuum. With engine idling, spraying some carb cleaner or similar at the tube caused engine rpms to go up and down. It needed to be fixed.

The steel tube connector rises up out of the intake manifold. It's the thinner hose, located forward of the thicker PCV hose that also rises up out of the intake manifold.

In this first photo, there's a rubber sleeve that I hose-clamped over the rusted steel tube connector. Testing with a spray can of carb cleaner showed it still leaked.

https://wbryga.bn1302.livefilestore....&cropmode=none

This next photo (below) shows the completed repair, or at least the part that's visible at the top side of the intake manifold. The old hose that went to the fuel pressure regulator (fpr) is still there, but detached from the fpr. The new hose is a 1/8" ID fuel hose. It's routed down through the manifold arms and is connected to another (original) hose down below using a hose barb.

https://wbo2pa.bn1302.livefilestore....&cropmode=none

This next photo (below) shows a closeup of the rusted tube, with the original hose still attached there but disconnected from the FPR. This is after the repair. Part of the new hose is visible in the upper right, crossing at an angle.

https://wbq8lw.bn1302.livefilestore....&cropmode=none

This photo (below) peers in under the intake manifold, from the driver's side. You can see the connector fitting with no hose on it - I pulled it off. The hose with the added new extension is visible just to the right. The plated hose clamp grips the 3/8" ID hose, with the original 1/8" hose inside it. You can see just a bit of the bright white hose barb, and the new 1/8" ID hose extending up from the barb. There's an electrical connector with the other half pulled off for better access. Remember to reconnect it. I posted the photo in high resolution so you can blow it up for a better view.

https://wbrrba.bn1302.livefilestore....&cropmode=none

Here's the repair I did.

I suspected and confirmed that the steel tube goes down through the manifold and connects to another hose beneath the manifold. A drawing from the parts desk at Honda shows that. You can replace the steel tube assembly ($35 part) but it's screwed to the underside of the manifold. I wasn't ready to learn how to detach the manifold, in order to replace the tube assembly.

The fix is to use a new 1/8" ID fuel line hose, from the FPR, down through the intake manifold arms, joined to the existing hose that originally went to the lower end of that rusted steel tube. There were a few things to deal with.

1) Find the other end of the steel tube. Use two hands under the manifold, one on each side. The tube bends towards the driver's side. You can just see the hose stuck on the end of the tube when you look in from that side.

2) Once I pulled the hose off the tube (not so easy with no easy access), I tried a 1/8" hose barb to join my new hose to the existing one. Nope. Old hose is all stretched out, the barb would not go in tight. And that skinny hose is too small for any decent hose clamp I know of.

Purchased a second hose, 3/8" ID. And a 14 mm. hose clamp. The really good kind that are made for fuel injection systems. I cut a 1" or maybe 3/4" piece of the 3/8" ID hose. Put the hose clamp on it and tightened it up just a bit. Put a little lube inside it and slipped it over the end of the existing hose that I had pulled off, from under the intake manifold.

Be careful. I never did see exactly where that hose goes. I have no clue what work it would be, to take stuff apart for access, if that under-the-manifold vacuum hose got pulled off wherever it's other end goes to.

3) Before putting the hose barb into the under-manifold hose, put it into one end of your new 1/8" hose. Then into the under-manifold hose, which already has the 3/8" ID hose plus clamp slipped onto its available end. Tighten up the whole thing. I used a 7 mm. socket on a screwdriver-handle type "wrench". I was just able to get my fingers in there to do the job.

4) Thread the other end of the new hose up through the manifold arms and onto the connector on the fuel pressure regulator. Again, some lube on the outside of the metal nipple helps the hose slip on. It must be a metric size, about 1/2 mm bigger than the 1/8" ID hose you can buy in the good ole USA.

You're done. No more vacuum leak.

It's really hard to work and see under the intake manifold.. There's just enough room to do the job, if you're patient.