Flooding Out

[chuckndonna67]

Jeep Motor Mount Bracket Location?

:?: Every time the weather gets cold the problem occurs
I have an '88 YJ, L6, Auto, Carter Carb.
If the mosheen sits overnight I depress the pedal down one time and it starts most times right up (although it sounds like it running on 4 cyl until the temp comes up. BUT if I let the mosheen sit one to two hours after use then start it it floods out everytime and then I'll spend 5 minutes or so trying to dump the fuel build-up before it turns over then trying to get it to smooth out. What's wrong? I have tried not depressing pedal, depressing pedal half way, pumping pedal---everything results in flooding. Need cause/solution please. CAB

 

[Tug-n-pull]

I have an '88 YJ, L6, Auto, Carter Carb.

Not to give you a short answer but I think the carter is your problem as it is on all most all carter equiped jeeps. tug

 

[Inspector-Gadget]

Hello chuckndonna67,

My guess: automatic choke vacuum break non-functional.

Clue 1: Problem occurs every time weather gets cold.

Clue 2: Motor sits overnight and cools down to where it needs and can ingest the very rich air-fuel mixture provided by a fully closed choke, so the motor starts and runs -- poorly -- but it starts and runs.

Clue 3: Motor sits for two-hours and only partially cools down, but in that time the automatic choke re-closes, giving the partially warm motor an overly rich air-fuel mixture on the next start-up. The motor starts and then drowns because the vacuum break is not cracking open the choke.

Solutions, in order of likelihood of cure:

1. Check vacuum break operation (the silver dollar sized vacuum diaphragm at the rear of the carb base) for functionality. The diaphragm should retract and the choke plate should open a bit as soon as engine starts and produces manifold vacuum.)

2. Check electrical connections to choke heater and manifold heater.

3. Crank automatic choke in small increments toward a leaner mixture.

Again -- my guess -- but hoping it helps.

Gadget

 

[richsia]

I have the EXACT same problem... Still have it with the Webber.
Starts up just fine when cold, but after some driving, and I let it sit for over 5 minutes, I need 5 minutes to start her back up due to the carb being flooded.
I checked the choke plate, and she's operating fine...
I re-adjusted the lean idle mixture, and she's good, so my next guess would be that she's running too rich.
I had a fuel pressure regulator (pep boys 15 bucks) on there, but removed it... i'll put it back on and let you know the outcome

 

[jeep90]

hey richsia

your posts always make me laugh because its like you stole my jeep, or vice versa. i am having the same problem as described above. in the morning does your jeep start, then shut off and you have to start it again? anyway, the weber requires a key hot wire going to the electric choke. im not sure about yours but i tested my wire going to the electric choke with a hot wire tester. turned on the key and no juice. started the jeep and boom i have juice going to the wire. shut it off to check again with the key on, no juice. it seems that the wire that went to the carter carb for the choke is only live when the jeep is running. hence the starting and immediately shutting off, then quickly start again when the plates are partially closed and she fires right up. it only does this when cold. i will run a key hot wire and see what happens.

 

[jeep90]

oh and a fuel pressure regulator helped me about this much....NONE.

 

[Inspector-Gadget]

Hi jeep90,

If your Jeep is 4.2, I-6 engined, the lack of electrical power to the automatic choke with key on, but engine not running, is entirely normal. The automatic choke is not supposed to be supplied with electrical power until the engine is running.

This selective electrical power application is accomplished by running a source of 12-volts through a pressure activated electric switch that is mounted on the oil pressure sending unit. (lower rear passenger side of engine)

When the engine is started, oil pressure goes up which causes the oil pressure sending unit mounted electrical switch to close, which in turn then routes 12-volts to the automatic choke heating coil.

The thinking behind this scheme is that you don't want the choke heater operating and pulling the choke open prematurely while the key is on, but the engine not yet started.

So, the Jeep, as originally wired, provides key-on hot, but delayed, (not until the engine is running) electrical power to the automatic choke heating coil.

Regards,

Gadget

 

[richsia]

Jeep90... I think everyone with a 90 YJ has the same problems as we do.
You mentioned a few weeks back that you were planning on running the nutter bypass, have you had a chance to? let me know

Here's what happens to me on a cold morning...

Get in, press gas, start jeep (1-2 cranks), fast idle works fine... she'll get up to 2200 rpms, let her run for 1-2 minutes, press gas again to deactivate fast idle. all that is fine...
but if i shut off the car for over a few minutes... i'll try to start her back up, and it takes almost 5 minutes of cranking, pressing gas, waiting, over and over until she'll start up... but after she starts, she's fine

i've leaned her out as much as possible to avoid running rich...
but this still happens, every indication points towards choke or "vapor lock" but i know it's neither

Maybe it's the FLOAT BOWL LEVEL... I don't even want to mess with that

 

[jeep90]

hey richsia....
that sort of does sound like a float bowl level problem, BUT what are the odds that the weber that was designed for your jeep and my jeep both seem flooded after running for a few minutes? design flaw? mine does the same thing....weird :? . i have heard somewhere that you should get the optional smaller idle jets for the weber. anyone hear of this? i need to check her for vac leaks too....that may be the problem. plus you shouldnt call her a car, she gets upset...she is better than that. :lol: ... about the nutter bypass, i havent gotten around to this..busy at work. plus its too cold. as soon as i do i will let you know though.

Gadget....does this delayed power to the choke thing only apply to the stock carb, or all carbs? i have the weber and i am wondering if i should run a key hot wire to it...that is what the install guide said to do.

 

[Inspector-Gadget]

Hi again, jeep90,

jeep90 wrote:

Gadget....does this delayed power to the choke thing only apply to the stock carb, or all carbs? i have the weber and i am wondering if i should run a key hot wire to it...that is what the install guide said to do.

jeep90, in my post about the selective power to the automatic choke, I endeavored only to provide background information as regards why your automatic choke has 12-Volts applied when the engine is running, but 0-Volts when the key is on, but the engine is not running, and why (according to the Gospel of Jeep) that was done.

That said, I would certainly not contradict the Weber designers. If the Weber "install guide" directs that 12-Volts should be applied to the automatic choke at key-on, whether or not the engine is running, then I would configure the wiring to satisfy that direction.

What have you to lose by trying it out? I cannot envision how following that direction could damage anything, and maybe it would help. I bet there are several Weber transplant surgeons on this board who would be interested in your results.

Give it a shot, see what happens and then let us all know.

Regards,

Gadget