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PO174 and PO171 codes, 2000 Mercury Sable

OK - 3 common problems on 3 liter 2000 Vulcan engines. Check the vacuum line on the FPR (Fuel Pressure Regulator). If it comes right off the engine can go rich, but a minor air leak can make it go lean AT IDLE. It will have little or no effect at speed.

The connection on the EGR Vacuum line is also a common leak on that engine, both where the hard plastic line connects to the rubber elbow.

They also have intake manifold problems. Disconnect the plug from the ISC (Idle Speed Control) valve to do vacuum checks with propane or ether. Leaving it connected you can not detect the leak because the ISC compensates for any change in idle speed.Check between upper and lower intake manifollds

Reply to
clare
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Do you know of anywhere I can find diagrams/schematics for the locations of these items? I'm still pretty much working in the dark not having much luck finding the info. When I google it, I am coming up with other years models so not sure if they apply or not (Duratech and such).

It's so cold here that I am going to only be able to try out these things once or twice, so I want to be sure and do it correctly. I did find info on the FPR.... is the hose on the top or bottom of it and how would I know whether or not the line is bad?

Are these items reachable without ramps?

Thanks, Sam

Reply to
Sam Seagate

All are reachable without ramps. Look at the ends of the tiny hard plastic hoses - they have rubber "elbows" on them, or possibly just rubber hoses about an inch long. They crack and split. The hoses you are interested in there are less than 1/4" diameter and fit on little nipples sticking out of the vacuum actuator cans.

A smoke test is the most effective way of locating them, but we mechanics have been locating and fixing vacuum leaks without smoke testers for over 80 years - close to 50 for myself.

I'm looking at getting myself a smoke tester to make it easier on the more complex engines. Yours is simple as a sack of rocks compared to most!!!

Reply to
clare

I made a smoke tester yesterday and it only took a minute to reveal the problem-- the leak is somewhere under I think what is called the intake manifold (the piece the throttle body is attached to). Smoke came from nowhere else other than there. Now the issue is whether or not I have to remove this entire assembly as it looks like it and the throttle body are attached. I have plenty of questions to how to go about it if so, but at least I now see where the leak is coming from. If I can now get the leak remedied, I'll share at some point how I made the smoker.... about $30 using parts from Walmart.

Reply to
Sam Seagate

If you have the plastic dual plenum intake, there have been some incidents of holes in the plastic. So it might not be a hose, but the intake itself. It will have to come off and closely inspected.

bob

Reply to
bob

Luckily, it's I believe aluminum and not plastic. I am making progress removing the manifold, but slowly. With some help, I was able to find a video of the process for this particular engine, which is the Vulcan 3.0 OHV. There are a couple of things that I missed that are still bolted on.... EGR and there is a bolted strap between the manifold and engine.

I can lift the manifold just far enough off to see the gasket underneath. I'm not totally clear from the video exactly what would need replacing once I have the manifold off.... I assume this gasket needs replaced, but the video talks about "seals" so not sure what the difference is. I also wonder if the gasket needs greased in any way.

One good thing I've spotted is that the PCV value I keep reading about on these engines seems to be in good shape. If it ever fails, I believe I can replace it without removing the manifold.

Sam

Reply to
Sam Seagate

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