Good way to test if the return fuel line or vent line is clogged?
05-05-02, 11:38 PM
#1
Rotary Enthusiast
Thread Starter
Join Date: Dec 2001
Location: Atlanta
Posts: 918
Likes: 0
Received 0 Likes
on
0 Posts
Good way to test if the return fuel line or vent line is clogged?
Someone brought up that my problems with the car flooding on hot start may be do to excessive fuel pressure in the carb due to the return line being blocked or something like that. I'm trying to figure out a good way to check this.
This theory makes some sense. When I remove my gas cap, you can hear the pressure releasing pretty good. This seem like it may be a reasonable place to look?
Thanks
This theory makes some sense. When I remove my gas cap, you can hear the pressure releasing pretty good. This seem like it may be a reasonable place to look?
Thanks
05-06-02, 06:42 AM
#2
Senior Member
Join Date: Apr 2001
Location: Tenn.
Posts: 573
Likes: 0
Received 0 Likes
on
0 Posts
what kind of engine carb or fi, if its carb there is a metal check valve not far from the carb, clean it out and replace the same way u removed it (one way), replace fuel filter, and clean the two screens on top of the carb where the fuel line attaches, also have u checked that the "hot start assist thingie" is working,,,good luck
Last edited by DONNA; 05-06-02 at 07:03 AM.
05-06-02, 06:55 AM
#3
Nikki-Modder Rex-Rodder
Join Date: Feb 2001
Location: Trying to convince some clown not to put a Holley 600 on his 12a.
Posts: 2,890
Likes: 0
Received 14 Likes
on
6 Posts
It's a bad sign. It means your evaporative emission system has gone to hell. Two things are generally responsible for this. They are:
The charcoal canister has accumulated water, and is now a big useless can of wet sand serving as nothing more than a cork at the end of your breather line;
Or, your PCV valve (Positive Crank Ventilation) has become filled with ****...a mixture of oil and water emulsified into a sludge that inhibits flow, and is working its way thru the hose on its way to carb....Once again effectively blocking the flow of vapor that is to be made to the carburetor.
You need to understand the goal of the designers of the emissions control when diagnosing many of these engine problems with fuel delivery on cars that still have their E systems in place. That goal simply was to design a system that allowed your engine crank and gas tank to breathe while the car was on, and have the vapors that occur during expansion go into the carburetor as part of the intake air. That way they get all burned up yaddayadda. But when the car is off, there are solenoids that close up so that no vapors escape into atmosphere. One of these (like the PCV) may be failing you.
The goal was to build an airtight engine in the sense that NOTHING escapes anywhweres but thru the tail pipe.
Try doing a search. There's alot of info.
The charcoal canister has accumulated water, and is now a big useless can of wet sand serving as nothing more than a cork at the end of your breather line;
Or, your PCV valve (Positive Crank Ventilation) has become filled with ****...a mixture of oil and water emulsified into a sludge that inhibits flow, and is working its way thru the hose on its way to carb....Once again effectively blocking the flow of vapor that is to be made to the carburetor.
You need to understand the goal of the designers of the emissions control when diagnosing many of these engine problems with fuel delivery on cars that still have their E systems in place. That goal simply was to design a system that allowed your engine crank and gas tank to breathe while the car was on, and have the vapors that occur during expansion go into the carburetor as part of the intake air. That way they get all burned up yaddayadda. But when the car is off, there are solenoids that close up so that no vapors escape into atmosphere. One of these (like the PCV) may be failing you.
The goal was to build an airtight engine in the sense that NOTHING escapes anywhweres but thru the tail pipe.
Try doing a search. There's alot of info.
Last edited by Sterling; 05-06-02 at 07:00 AM.
05-06-02, 09:15 AM
#5
Rotary Enthusiast
Thread Starter
Join Date: Dec 2001
Location: Atlanta
Posts: 918
Likes: 0
Received 0 Likes
on
0 Posts
I am going to try disconnecting the charcol canister and see if that helps. I'm learning a little bit about this as a go, so I have a few things to try tonight.
05-06-02, 12:31 PM
#6
Open up! Search Warrant!
Join Date: May 2002
Location: Kicking down doors in a neighborhood near you
Posts: 3,838
Likes: 0
Received 3 Likes
on
3 Posts
The charcoal canister is a black box with a rubber hose going to it and it usually sits up front next to the fender. Check the Haynes book for your specific make/model. Also when you find the PCV Valve(positive crankcase ventilation valve) an easy check is to shake it. If you hear the needle inside rattle then it is good. If not, its a $3.00 fix.
Trending Topics
05-06-02, 10:49 PM
#10
Rotary Enthusiast
Thread Starter
Join Date: Dec 2001
Location: Atlanta
Posts: 918
Likes: 0
Received 0 Likes
on
0 Posts
Well, I got it to start tonight while hot with considerable less smoke after opening the gas cap like the person suggested to relieve pressure, but it's still not to where it was before I changed carbs. Just telling myself...baby steps.....
05-06-02, 11:33 PM
#12
Banned. I got OWNED!!!
Join Date: Jan 2002
Location: Da Barrio!!!(Irving, Texas)
Posts: 984
Likes: 0
Received 0 Likes
on
0 Posts
ok... well..... someone tell me what I should do.... It rained a day or two ago.... and I left me air lid box with the charcoal canister outside.... what should I do??? THANX..... LATERZ
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
07-01-23 04:40 PM
