PCV hose

[Pulse97]

Aloha team, 3 quick questions:
1. Anyone have tips for determining if the PCV hose from the back of the engine is bad? How about replacing it- any easy way to remove/replace?
2. I just replaced intake gaskets - how can I tell if I'm still leaking?
3. Where else to look for a persistent 171 code and a rough running engine?
Thanks!

 

[1997XLTRollover]

Get a cheap cigar, take a puff and blow smoke down the tube. See if it leaks out somewhere.

 

[chefduane]

Do this:

http://www.explorerforum.com/forums/showthread.php?p=2308817

Also, did you replace both upper and lower manifold gaskets?

 

[Pulse97]

Thanks chefduane! Yes, I replaced both. I am running out of ideas. So far I can't find any obvious vacuum leaks but the engine stumbles when you rev the throttle, has rough idle, and still throws the 171 code. i put on new wires and plugs, cleaned the MAF sensor and throttle body and cleaned the upper intake manifold.

 

[chefduane]

Have you checked the IAC? Idle Air Control. Should be under the plastic shroud cover of the manifold. Easiest thing to do is give it a good cleaning. Search "IAC" here. There are numerous threads about IAC's.

 

[2000StreetRod]

P0171 System too Lean (Bank 1)

Bank 1 is the passenger (right) side of the engine. Check all of the vacuum hoses on that side: Intake manifold vacuum lines . Your 1997 has VIS. Check the hoses for it: VIS Conversion

 

[Pulse97]

Thanks 2000streetrod. You have some awesome posts my friend- mahalo!
I checked all the vacuum hoses and cleaned the IAC valve. No change. I put a stethoscope on the lower intake manifold and hear what sounds like a pretty good hissing from the front left port. I recently changed the gaskets - may have screwed something up. Any thoughts on whether to go to a thicker gasket? Any tips on best way to clean the gunk and old gasket residue?

 

[2000StreetRod]

where leaking?

Is the leak you detected between the head and the lower intake manifold or is it between the lower and upper intake manifold?

I've only used gaskets that were in a kit designed for the engine. I suppose that you could find thicker O rings of the correct diameter for between the head and the lower intake manifold. If so, make sure they are specified for a suitable high temperature.

 

[Pulse97]

It's leaking between the head and the lower intake. I bought some OEM gaskets today and will install tomorrow. I used felpro last time and I noticed the OEM are slightly smaller. Perhaps they'll give a better seal.

 

[Pulse97]

171 gone - now 174

Well team, I'm out of ideas. I put new upper and lower intake gaskets on, checked vacuum hoses, and initially truck sounded much better. Went to put gas in (was on E) and when I started up, CEL came on with a 174 and 705 instead of 171. Truck has new plugs, new wires, but there's a definite spark knock and loss of power. Any suggestions?
Forgot to add - I put a bottle of royal purple in the tank before heading to the gas station- not sure if that we affect anything.

 

[2000StreetRod]

fuel pressure?

Have you measured the fuel pressure? Maybe the fuel pump is weak.

 

[Pulse97]

Fuel pressure is right at 30 - the minimum. I'm thinking that shouldn't cause it to throw a code.

 

[Pulse97]

Ok, I took it to Ford. The diagnosis: bad compression on bank 2 caused by some sort of internal engine problem. Bad o2 sensor as well. I'm planning to drive it until it goes for good - not worth h the cost to rebuild. Thanks to all for your help!