Canister Purge Valve Question

[MyrtleBeachFord]

Quick question....

On the canister purge valve, once the vacuum hose is hooked to the one end of the valve, shouldn't the other end OF THE VALVE have suction? (the port that goes to the canister itself)

Another question...can't the canister purge valve be bypassed?

JEFF

 

[shamaal]

Quick question....

On the canister purge valve, once the vacuum hose is hooked to the one end of the valve, shouldn't the other end OF THE VALVE have suction? (the port that goes to the canister itself)

Another question...can't the canister purge valve be bypassed?

JEFF

The purge valve is the vent for the gas tank. One end (input) has vaccum, the other end (output) will have vacuum when the purge is commanded to open by the computer.

Bypassing the purge valve will cause a constant vacuum in your tank and constant evaporation of the fuel.

 

[MyrtleBeachFord]

Oh, ok - thank you. Just wanted to make sure. I'm still getting a rough idle, black smoke out of the tailpipe and CEL. I've gotta change the FPR, I think....

Another question about the CPV..... on the input side that goes to the vacuum port near the throttle bottle or intake (or wherever that is), the hose that slides on that port is slightly kinked and is not the right size for that port either, so I hear some air escaping. Could that cause the black smoke, rough ride, CEL or gas odor?

Jeff

 

[shamaal]

Yes sir, depending on the severity, any leaks in the vacuum line can cause the symptoms you described.

If symptoms still exist after fixing the vacuum leaks. There are a number of other possible causes. Is there any particular reason you suspect the FPR?

Do some searches, feel free to ask questions, this group has a lot of knowledgeable people.

Is the Check Engine Light (CEL) on?

 

[MyrtleBeachFord]

Yes, CEL is defintely on. This has been an on-going problem for me for quite sometime. Initially, I had a really rough idle, fluctuating by itself, but after I cleaned the MAF, IAC, reinstalled a new PCV valve and reconnected a few vacuum hoses that clearly came off - the rough fluctuating idle stopped. Then came poor gas mileage, black smoke out of the tailpipe and a really disturbing foul odor from the tailpipe. First I suspected the MAF was bad, but don't think it is, after inspection. I changed the Canister Purge Valve and reset the computer, still same symptoms. I am defintely running really rich. So I'm thinking it's either the FPR or maybe a Fuel Injector stuck open (which I dont have the tools to diagnose and fix).

I'm gonna pick up a used FPR at the junk yard and see if that does the trick. Any other suggestions?

 

[shamaal]

Posting the codes will greatly help in assitance and recommendations.
See the EEC IV forum
http://www.explorerforum.com/forums/forumdisplay.php?f=114
for directions. Ask questions for the bits you do not understand. The auto places will pull codes for free also, but may no longer have the readers for the early models.

Generally speaking your symptoms speak of running rich. The high sulfur gas used outside of California, produces a 'rotten egg' smell. If you have an automatic transmission and are blowing the vacuum hoses off, that's a sign of a bad modulator, there will be ATF around the vacuum tree and it gets sucked into the intake. To check the FPR, a gauge can be connected to the schrader valve on the fuel rail. Pressure should be 30 - 45 psi.

At any rate try some searches and ask questions.

 

[MyrtleBeachFord]

Thanks Shamaal...

I actually have already replaced the Tranmission Vacuum Modulator. I replaced it after noticing that when I pulled the hose off, ATF came running out. That was about a month ago.

...Still same symptoms though. I've tried numerous Advance Auto Parts and AutoZone stores in the area and they won't pull codes for anything older then a 95, they supposedely "don't have the connection for it".

Is there a thread you know of listing any 1st Gen Explorer owners who are parting their trucks?

JEFF

 

[shamaal]

Try a search on '91 parts'. I get a couple recent hits. It seems to me ther's a way to read the codes by counting the flashes on your CEL after jumpering a connector. Perhaps someone can point you in the right direction. I could never find the right connectors.
Good Luck!

 

[MyrtleBeachFord]

Jumpering CEL?

So I can get codes without hooking up a code reader? How can I do this?

Jeff