TheSamba.com :: View topic - fresh rebuild first start plugged fuel return line or oxs?

Sun Apr 29, 2012 5:05 pm

:? 91 2.1 vanagon. i have a new tank and replaced all the rubber fuel lines. at first start i forgot the return line at the tank and had fuel everywhere :shock: but as soon as we hooked it up it started to run like crap, unhooked and let it flow in a can and it ran better. then the plastic return line somehow got pluged up but now it clear, but still once we hooked it back up it starts to load up and runs rich. :? ok saying all that i feel its the ox sensor or it acts just like my other vanagon did a few years back, once you start it, it runs great for about 2 min and then it starts to run rich and stinks. my buddy moved the ox wire and it started running better and the return line is flowing well for now, i'm afraid it well start acting up again and i'm not so sure whats going on. is it a fuel flow problem or a short in the ox sensor wire? btw i have new coolant sensors. any ideas????

Sun Apr 29, 2012 5:09 pm

Sounds like you have a bunch of things to test.

Sun Apr 29, 2012 5:12 pm

the one thing i wish i would have done is clean and blow the old plastic line out.

Mon Apr 30, 2012 3:58 pm

Is that all the help i get? thanks for all the help. SMH

Mon Apr 30, 2012 4:00 pm

Clearly the O2 wire is boofed,fix it and see what happens next.

Mon Apr 30, 2012 4:11 pm

9 times out of 10 its the wire shorting out right?

Tue May 01, 2012 4:52 pm

so it starts fine cold and sounds great, but as it was idling about 4 min it cut off and would not start. once it did start it started to stumble,buck, pop and snort, whats going on?? could the fuel pressure regulator make it do this???

Tue May 01, 2012 5:06 pm

you tell us.
test the fuel pressure.

Tue May 01, 2012 6:45 pm

I guess you got a point but everything is new or known to be in good cond. the fact is i have done everything by the book other than we put the dist gear in wrong. so how about some ideas please[/code]

Tue May 01, 2012 6:54 pm

you are not listening,get fuel pressure gauge,VOM,bently and do the basics, it is usually something shi# simple!

Tue May 01, 2012 6:56 pm

if you think the o2sensor might be at fault, cut out the crimp joint and solder the joint, and cover it in heat shrink

there's an outlet on the fuel pressure regulator, it has a small bolt in the top of it
you could connect an oil pressure gauge to that, that would tell you the fuel pressure
how clear are the breathers on the fuel tank, does it make a difference if the fuel cap is off, while you run the engine ?

Wed May 02, 2012 12:12 am

Well, if all the parts are 100%, that leaves assembler error.
As stated previously, you have many tests of all systems ahead of you.
If you feel it is the FP regulator, test it :!:
Not sure what you want readers to tell you other than that.

Wed May 02, 2012 6:20 am

Devesvw-
I know your frustrated. It can be after a new install and things
don't go right. Problem is even new parts can be faulty or a bad
connection can make a good part appear faulty.
Your best bet would be to follow the flow chart available in
the fuel injection guides testing everything in the order they
tell you to. You don't want to assume anything is good until
the meter,test light or fuel pressure gauge says it is.
I will mention though that when you first start a motor that
for the first couple minutes the ecu is ignoring the O2 sensor.
Then as it warms up it is brought into the information the ecu
is using to run the system. If you turn the can off and back on
it will ignore it again for a minute or two. It's very important that
none of the wire strands in that coax wire are not shorted to the
center wire. Even one tiny hair will mess it up.
I think the curve ball here is the fuel problem you have that
until diagnosed makes it hard to proceed or anyone to help.
A return line clog is very rare because if that much debris is
in the system it will usually clog the injectors,fuel filter,pump
first. Checking the fuel pressure needs to be done so the fuel
regulator can be ruled out and that the tank is venting properly
so the charcoal filter isnt clogged.
Like I said before I know your frustrated but don't let it get
you down. Step back,check the O2 wiring and then take the time
to go through the fuel injection manual,testing everything in
order and let us know what you find from there.

Wed May 02, 2012 4:29 pm

OK ALL IS GOOD AND A BIG THANK YOU it was the ground wire placed on the dist spade and not at the block :oops: and just in case i replaced the idle stabilizer control unit.