Vacuum octypus problem

[KBoomBoxx]

So for the past few weeks I have trying to determine where the faint smell of raw gass has been coming from without success... also, about 2 weeks ago, where the the vaccum lines meet together in the engine (otherwise referred to as the vacuum octypus) have a hard cap on one of the openings that at some point in time the cap blew off... I replaced the cap, but noticed that some times I have difficulty starting the engine... it may 2 or 3 cranks before the engine turns over... well last night I have the same problem, only this time I heard a loud noise and the cap came off the vacuum octypus...

Can someone help me diagnose the issue? These are the only symptoms... no check engine lights come on... no problems with the engine... it doesn't seem to idle as nice as it did when I first got it in January 2006, but it does have 145,000 miles on it... I thought I read something about the fuel pressure regulator? or something with the fuel lines (which would explain why I have the faint smell of raw gas still)... any suggestions would be appreciated.

 

[ma96782]

If you haven't yet............INVEST...........in a HAYNES Manual.

Chapt 4 deals w/ Fuel and Exhaust Systems.

Anyway...........the fuel smells could be as simple as a leak, or evaporator canister, or alot of other small things.

As for the idle.....there are many posts (SEARCH) about that problem........and there are many fixes that have worked for different people (and some that haven't).

Try to narrow down your "problems." Perhaps, it's just time to do a, "tune up."

Aloha, Mark

 

[KBoomBoxx]

I have the Haynes manual and yes its a good investment for fixing and solving minor problems, but they are never as detailed as the actual service manual.... the search function has not been working as of right now so, I thought that there was a posting that talked about the cap flying off and what potentials problems were the cause?

 

[ma96782]

Good show.......

Now, which "octopus", (the one that comes to my mind is the one next to the A/c evaporator).

When all else fails........could you post a pic? If not here, how about on another site?

My vehicle isn't at home right now (I've the same year vehicle).....but, seeing a pic may help to know exactly what you're refering to.

Could it be that, "engine backfire" is popping off the line?

Or some other source of built up pressure. So, trace back the vacuume line to source.........what is it connected to?

Aloha, Mark

PS..........as for the idle........you may just need a tune up..........when was the last one? Plugs, wires, clean (or replaced) IAC, MAF, TB.

 

[ma96782]

This may help:

Vacuum Line Diagrams

http://www.explorerforum.com/forums/showthread.php?t=154816



Aloha, Mark

 

[KBoomBoxx]

This may help:
Vacuum Line Diagrams
http://www.explorerforum.com/forums/showthread.php?t=154816
Aloha, Mark

In the diagram from the attached thread I will need to go through each of the lines and see if I can diagnose a potential problem. The search button is working again and I read that I might have a modulator problem. What does the modulator do? It would appear to be a part that sits on top of the transmission and is only accessible through the floor from the interior. Any idea how to test and see if it is indeed the modulator? Any idea of a part # from AutoZone or other parts store?

 

[LXNavajo_94]

you also might want to check you trans vacum modulator it caused my lines to come off like that

 

[shamaal]

A couple possibilities come to mind

1. As mentioned, if you have an automatic transmission, they are notorious for blowing the lines off the tree when the modulator fails. There is usually automatic transmission fluid around the line or the tree if it happens. The slight smell of gas may be from the carbon cannister line that is now escaping through the tree.

2. There has been at least one instance where the fuel pressure regulator has gone bad and leaks gasoline into the vacuum line.

MA96782 recommendation to buy a Haynes manual is a good one. It gives you basic information, some nice drawings and a basis for information you may read. Search the forum, ask questions, spend the 20 bucks to become elite.

 

[Bryce]

Mine does the same thing.

Wow, my '91 does the exact same thing.

The 'popping' noise that occurs when I'm trying to start the truck is absolutely a backfire. It doesn't backfire very often, but when it does it usually blows the vacuum lines off.

The vacuum lines have become loose and that's why they come off easily. I've noticed oil residue on the connections. A mechanic told me once that when the piston rings wear out there can be some oil "blow back". I guess pressure escapes past the rings and causes oil to spew out various orfices of the block / intake. The engine in my truck is coming up on about 325K miles so I guess the rings are probably a little worn. I had a similar problem with an old Marquis with a Ford 5.0. It used to get oil stains on the air filter. Anyway, the point is that the vacuum lines are all greasy and they slip off easily when the engine backfires.

I always thought that the gasoline smell was unrelated to the vacuum lines. Now that I look at the vacuum line diagram I guess they could be related. I think the charcoal canister on the gas tank is probably clogged / leaking and that is why I get the gas smell. It's the 'vapor recovery' system right? Now that the truck isn't recovering vapors, I can smell them.

 

[shamaal]

Your symtoms describe the blown transmission modulator problem. If you have an automatic transmission I would look for that first. The symptoms are oily and loose hoses and transmission fluid in the line that goes to the transmission. To replace:
http://www.explorerforum.com/forums/showthread.php?t=62684&highlight=access+panel+modulator

The evap recovery sytem vents the tank to the cannister. The cannister solenoid empties the cannister into the intake manifold. The smell of gas can be the gas vapor going through the manifold and coming out the open vacuum tree when the engine's off. The other less likely possibility is a bad FPR leaking gas into the vacuum hose.

Do some searches, ask some questions.

 

[AlsExplord]

Bolts Just Turn


I have the exact same problem as described at the start of this thread, and happily took the great advice. Bought my vacuum modulator, removed the 2 bucket seats and console, peeled back the carpet and there it was; the shiny access plate on the hump. Thing is, they just turn and turn. I shot wd40 on 3 of the 4 from underneath(couldn't find the 4th), and still nothing. Anyone have any ideas? I'm tired of buying quarts of ATF... :fire: