International Full Size Jeep Association
Home Forums Reader's Rigs Tech Library Trail Stories FSJ-List
International Full Size Jeep Association  

Go Back   International Full Size Jeep Association > Tire Kickin' > General FSJ Discussion

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 10-24-2011, 01:04 PM
Blake Blake is offline
Bleedin' Gasoline
 
Join Date: Dec 22, 2005
Location: longmont, colorado
Posts: 2,123
MC2150 carb bowl is dry after sitting overnight

I'm troubleshooting a bad cold start condition on my '88 waggy with the Motocraft 2150 carb. I think I know all about how to adjust the choke, fast idle, fuel filter orientation, emissions systems, etc.

The waggy has been sitting in the garage since yesterday afternoon. I went home for lunch and my suspicions were true - the carb bowl was 95% empty. I think the bowl vent is doing it's job - venting the carb bowl and returning it to the tank.

So my question is surrounding this;

How can I circumvent this? Electric pump that can 'fill up' the bowl? Remove the vent system? Install a Holley Truck Avenger?
__________________
Please come on over to http://fsjnetwork.com/forum and have a look.
Reply With Quote
  #2  
Old 10-24-2011, 01:07 PM
Ristow Ristow is offline
 
Join Date: Jan 20, 2006
Location: The Great Googley Moogley Midwest.
Posts: 17,192
the vent cannot empty the bowl. once the fuel is in the bowl it can either leak out,like through the power valve,or evaporate.
__________________
Quote:
Originally Posted by Hankrod
Ristows right.................again,




Quote:
Originally Posted by Fasts79Chief
... like the little 'you know what's' that you are.




Quote:
Originally Posted by Fasts79Chief
I LOVE how Ristow has stolen my comment about him ... "Quoted" it ... and made himself famous for being an ***hole to people. Hahahahahahahahahha!


→ Where the kids hang out...

fsjbuilder.org come for the mindless chat,stay for the hand drawn emoticons.

It's like you're unraveling a big cable-knit sweater that someone keeps knitting...and knitting...and knitting...and knitting...
Reply With Quote
  #3  
Old 10-24-2011, 01:25 PM
derf's Avatar
derf derf is offline
360 AMC
 
Join Date: Jul 12, 2001
Location: Littleton, CO
Posts: 3,403
I can let mine sit for a couple of days without it evaporating.

You could be getting heat soak causing the fuel to evaporate too rapidly. Is your spacer in good shape?

Your float could be set too low and you don't have enough to last overnight.

Is your bowl vent hooked up to the evap canister (or capped)? If not, the evaporation could be accelerated.

Perhaps you have some grit or damage on the needle/seats allowing it to flow back into the line and back to the tank somehow.

You may be leaking through the power valve at the bottom of the bowl. How's your valve and gasket look?

It could be a combination of more than one of those too.
__________________
Try out my gear ratio calculator

My Jeeps: Truck Norris and Grimm Jeeper

Truck Norris doesn't need a brow. He has fists.
Reply With Quote
  #4  
Old 10-24-2011, 01:41 PM
Blake Blake is offline
Bleedin' Gasoline
 
Join Date: Dec 22, 2005
Location: longmont, colorado
Posts: 2,123
I've recently rebuilt the carb and have a new PV, gasket, spacer, needles, float, etc.
__________________
Please come on over to http://fsjnetwork.com/forum and have a look.
Reply With Quote
  #5  
Old 10-24-2011, 01:45 PM
twmattox twmattox is offline
350 Buick
 
Join Date: Feb 24, 2003
Location: Indiana
Posts: 1,282
I have a similar issue. I know my spacer and fiber gasket are fully in tact. I know the power valve is new (with the rebuild kit). I know my bowl vent is fully operational (new replacement). I know my needle and seat are not "backflowing". I know my float is set to the correct level.

To me, this means that my power valve is leaking somehow (even though it is new). It is the only thing that makes sense. It does not leak through the diaphragm. But, I think it may be leaking by the seal (kind of like a bathroom sink draining).

My plan is to buy a better quality power valve and try a single stage version to see how it works.

I will post up when I get around to getting this done.
__________________
'83 Scrambler (CJ-8) / 258 / T-5 / D-300 / DANA 30-AMC20 (3.31)
'88 Grand Wagoneer (SJ) / 360 / TF727 / NP229 / DANA 44 (2.73)
'05 Wrangler Unlimited (LJ) / 4.0L / NSG 370 / NV231 / DANA 30-44 (3.73)
'15 Wrangler Unlimited (JKU) / 3.6L / 42 RLE / NV 241 / DANA 30-44 (3.73)
Reply With Quote
  #6  
Old 10-24-2011, 02:10 PM
derf's Avatar
derf derf is offline
360 AMC
 
Join Date: Jul 12, 2001
Location: Littleton, CO
Posts: 3,403
Quote:
Originally Posted by Blake
I've recently rebuilt the carb and have a new PV, gasket, spacer, needles, float, etc.

I've gotten new parts that were broken before. I once bought a new fuel pump off the shelf that didn't work and I had to exchange it. I'd check the power valve just to be sure. I'd double check the float level as well. I'd also give the needle and seat a once over. It never hurts to double check everything. Even I make mistakes once in a while and I have to go back and fix something I've just rebuilt.
__________________
Try out my gear ratio calculator

My Jeeps: Truck Norris and Grimm Jeeper

Truck Norris doesn't need a brow. He has fists.
Reply With Quote
  #7  
Old 10-24-2011, 02:39 PM
Blake Blake is offline
Bleedin' Gasoline
 
Join Date: Dec 22, 2005
Location: longmont, colorado
Posts: 2,123
I'm gonna pull the PV vacuum hose off and see if there is any fuel in there.

I have several Holley power valves laying around, all in good shape. They appear to be about the same as the MC PV. Will a holley PV work in a MC carb?
__________________
Please come on over to http://fsjnetwork.com/forum and have a look.
Reply With Quote
  #8  
Old 10-24-2011, 03:41 PM
Ristow Ristow is offline
 
Join Date: Jan 20, 2006
Location: The Great Googley Moogley Midwest.
Posts: 17,192
the threads are too short. you'll get a turn or so out of it before it tightens up.

Quick Fuel PV's are longer.
__________________
Quote:
Originally Posted by Hankrod
Ristows right.................again,




Quote:
Originally Posted by Fasts79Chief
... like the little 'you know what's' that you are.




Quote:
Originally Posted by Fasts79Chief
I LOVE how Ristow has stolen my comment about him ... "Quoted" it ... and made himself famous for being an ***hole to people. Hahahahahahahahahha!


→ Where the kids hang out...

fsjbuilder.org come for the mindless chat,stay for the hand drawn emoticons.

It's like you're unraveling a big cable-knit sweater that someone keeps knitting...and knitting...and knitting...and knitting...
Reply With Quote
  #9  
Old 10-24-2011, 05:40 PM
talntar's Avatar
talntar talntar is offline
 
Join Date: Jun 12, 2002
Location: ansonia ct. 06401
Posts: 5,530
make sure your filter is in the right position.it can siphon back to the tank.
__________________
85 gw 215k and still going
castrated(de-wooded)360 2" espo springs 31x10.5
89 gw,free,almost legal

She can dance a Cajun rhythm,Jump like a Willys in four wheel drive,

the world is full of kings and queens who blind your eyes and steal your dreams

"Our militarized "law enforcement" has become the standing army our founders feared"
Reply With Quote
  #10  
Old 10-24-2011, 05:45 PM
Ristow Ristow is offline
 
Join Date: Jan 20, 2006
Location: The Great Googley Moogley Midwest.
Posts: 17,192
it cannot. the fuel inlet needle is above the fuel level. how the heck can it siphon it back?
__________________
Quote:
Originally Posted by Hankrod
Ristows right.................again,




Quote:
Originally Posted by Fasts79Chief
... like the little 'you know what's' that you are.




Quote:
Originally Posted by Fasts79Chief
I LOVE how Ristow has stolen my comment about him ... "Quoted" it ... and made himself famous for being an ***hole to people. Hahahahahahahahahha!


→ Where the kids hang out...

fsjbuilder.org come for the mindless chat,stay for the hand drawn emoticons.

It's like you're unraveling a big cable-knit sweater that someone keeps knitting...and knitting...and knitting...and knitting...
Reply With Quote
  #11  
Old 10-24-2011, 05:47 PM
talntar's Avatar
talntar talntar is offline
 
Join Date: Jun 12, 2002
Location: ansonia ct. 06401
Posts: 5,530
what i can say is that is what fixed it on mine
__________________
85 gw 215k and still going
castrated(de-wooded)360 2" espo springs 31x10.5
89 gw,free,almost legal

She can dance a Cajun rhythm,Jump like a Willys in four wheel drive,

the world is full of kings and queens who blind your eyes and steal your dreams

"Our militarized "law enforcement" has become the standing army our founders feared"
Reply With Quote
  #12  
Old 10-24-2011, 06:13 PM
Rich88's Avatar
Rich88 Rich88 is offline
FSJ Maniac
 
Join Date: Nov 20, 2008
Location: Wilds of Ellington, CT
Posts: 4,182
Quote:
Originally Posted by Blake
I'm troubleshooting a bad cold start condition on my '88 waggy with the Motocraft 2150 carb. I think I know all about how to adjust the choke, fast idle, fuel filter orientation, emissions systems, etc.

The waggy has been sitting in the garage since yesterday afternoon. I went home for lunch and my suspicions were true - the carb bowl was 95% empty. I think the bowl vent is doing it's job - venting the carb bowl and returning it to the tank.

So my question is surrounding this;

How can I circumvent this? Electric pump that can 'fill up' the bowl? Remove the vent system? Install a Holley Truck Avenger?

Bowl vent is out the top of the carb, and can only vent fumes unless you roll the Jeep upside down. Therefore its impossible for the gas to go that way.

Re-engineering by removing the vent or installing an e-pump will not cure the basic problem. Getting a new carb is an expensive waste of money unless you want on anyway for the heck of it.

It is also physcially impossible for gas to jump the air gap up to the needle valve intake and drain back into the tank...and regardless of the infamous fuel filter wrong position syndrome.

Also, I assume that this did not used to happen but now it does. This eliminates boiling out.

This leaves draining out through the power valve as most likely.
__________________
Jeepasaurus (Wagonus Grandi quadropedus)
88 GW 360-.030 over/2150/727/229/Posi, e-pump, AC (broke), tow package, Monroe Air Shocks, TFI, CTO-Free, AIR-free, oil & tranny coolers, dried knuckle blood all over, GM 350 TBI in a box, waiting...
"You're an FSJ'r when the parts guys memorize your name, phone & credit card#."
Reply With Quote
  #13  
Old 10-25-2011, 12:33 AM
Blake Blake is offline
Bleedin' Gasoline
 
Join Date: Dec 22, 2005
Location: longmont, colorado
Posts: 2,123
I pulled the power valve vacuum line tonight after it had been sitting for 2 hours.

Not a single drop or hint of fuel was in that line. Zero.

So what does that leave me? how else can fuel escape the carb?
__________________
Please come on over to http://fsjnetwork.com/forum and have a look.
Reply With Quote
  #14  
Old 10-25-2011, 05:35 AM
twmattox twmattox is offline
350 Buick
 
Join Date: Feb 24, 2003
Location: Indiana
Posts: 1,282
Like I posted above, I think the fuel slowly drains past the power valve, through the internal channels, down into the intake.

The diaphragm just pulls the power valve closed (under vacuum). If it is ruptured, it will allow fuel to drain out the manifold line you looked at and the power valve will not work like it should. However, if it is not ruptured, it doesn't mean that the power valve is not leaking internally. Think of the power valve like the drain plug in your bathroom sink. The diaphragm would be like the actuator that raises and lowers the power valve. You can pretty easily tell if the actuator is leaking. But, if it is dry and functioning, it doesn't mean that you can fill the sink and the drain plug won't leak.

I think that my situation is a bit worse because I think my fuel line drains back as well. It takes about 45-seconds of cranking (or more) for me to finally fire up. I have checked the fuel filter and new fuel pump. So, I will be looking for a pinhole leak in my fuel line next. Even with a dry bowl, if fuel were in the line at the fuel filter level, it shouldn't take too long to get it to fill the bowl and fire.
__________________
'83 Scrambler (CJ-8) / 258 / T-5 / D-300 / DANA 30-AMC20 (3.31)
'88 Grand Wagoneer (SJ) / 360 / TF727 / NP229 / DANA 44 (2.73)
'05 Wrangler Unlimited (LJ) / 4.0L / NSG 370 / NV231 / DANA 30-44 (3.73)
'15 Wrangler Unlimited (JKU) / 3.6L / 42 RLE / NV 241 / DANA 30-44 (3.73)
Reply With Quote
  #15  
Old 10-25-2011, 07:01 AM
Comancheap's Avatar
Comancheap Comancheap is offline
Member
 
Join Date: Jan 27, 2010
Location: Indian Trail, North Carolina
Posts: 202
Yep after a few backfires (only thing I can think of different) mine is doing the same thing. If I had used it the day before it fired up quickly and choke stayed on.Now after a few backfires (down shifting to hear new muffler rumble ) anyhow mine is now taking like you said about 45 seconds of cranking and I can also see a little puddle of fuel mixed with oil on the intake on right front corner nearest accelerator pump.

You have any puddles on yours?
__________________
John

1977 FSJ, Autumn Red 360 roached gas tank to match exterior!

1972 Buick GS 455 Stage 1.Total basket

1960 Electra 225 convertible 401 Nailhead 445 ft lbs of torque.

1970 455 MF'in Muncie 4 speed Buick GSX rusty yet satisfying! Drive it sideways!

1986 Chevy Silverado Dads first nice truck, claimed by the woods : (
Reply With Quote
  #16  
Old 10-25-2011, 08:21 AM
derf's Avatar
derf derf is offline
360 AMC
 
Join Date: Jul 12, 2001
Location: Littleton, CO
Posts: 3,403
One experiment to try:

Take the carb off the manifold and set it on a stand (I use a couple of bolts through the mounting holes as legs). Supply gas through the inlet so it fills up to the limit where the float cuts it off. Let it sit for a while and see if gas is dripping from anywhere. After it sits overnight, open it up and check the level.

If it's still (mostly) full, then you have a fuel supply problem. Your fuel system is draining back and it has to prime to supply enough to get the truck started. If it's empty, you have a problem with the carb. The location of the leak should be noticable under the stand.
__________________
Try out my gear ratio calculator

My Jeeps: Truck Norris and Grimm Jeeper

Truck Norris doesn't need a brow. He has fists.
Reply With Quote
  #17  
Old 10-25-2011, 09:17 AM
Blake Blake is offline
Bleedin' Gasoline
 
Join Date: Dec 22, 2005
Location: longmont, colorado
Posts: 2,123
Quote:
Originally Posted by derf
One experiment to try:

Take the carb off the manifold and set it on a stand (I use a couple of bolts through the mounting holes as legs). Supply gas through the inlet so it fills up to the limit where the float cuts it off. Let it sit for a while and see if gas is dripping from anywhere. After it sits overnight, open it up and check the level.

If it's still (mostly) full, then you have a fuel supply problem. Your fuel system is draining back and it has to prime to supply enough to get the truck started. If it's empty, you have a problem with the carb. The location of the leak should be noticable under the stand.

It's supposed to snow here tomorrow, so my GF and I are going snow 'wheeling. She will take the waggy and I will take the Honcho. I'll remove the carb and set it on my custom carb stand that I made and see if it's leaking anywhere tomorrow night.
__________________
Please come on over to http://fsjnetwork.com/forum and have a look.
Reply With Quote
  #18  
Old 10-25-2011, 07:04 PM
Rich88's Avatar
Rich88 Rich88 is offline
FSJ Maniac
 
Join Date: Nov 20, 2008
Location: Wilds of Ellington, CT
Posts: 4,182
Quote:
Originally Posted by twmattox
I think that my situation is a bit worse because I think my fuel line drains back as well. It takes about 45-seconds of cranking (or more) for me to finally fire up.


Do us a favor: Next time you park for the night, crimp the fuel hose (gently) between carb and filter with something (like a small vice grips) and see if it really drains back or not. Before starting next time, remove crimp tool and see if you still have to crank for 45 seconds. Report back results.
__________________
Jeepasaurus (Wagonus Grandi quadropedus)
88 GW 360-.030 over/2150/727/229/Posi, e-pump, AC (broke), tow package, Monroe Air Shocks, TFI, CTO-Free, AIR-free, oil & tranny coolers, dried knuckle blood all over, GM 350 TBI in a box, waiting...
"You're an FSJ'r when the parts guys memorize your name, phone & credit card#."
Reply With Quote
  #19  
Old 10-25-2011, 08:38 PM
Rod2's Avatar
Rod2 Rod2 is offline
327 Rambler
 
Join Date: Apr 11, 2004
Location: Claremont NC
Posts: 645
Quote:
Originally Posted by Blake
I'm gonna pull the PV vacuum hose off and see if there is any fuel in there.

I have several Holley power valves laying around, all in good shape. They appear to be about the same as the MC PV. Will a holley PV work in a MC carb?
I don't know about the 2150, but the Holley is a direct replacement for the MC p-valve in the 2100.
__________________
Rod Skaggs
'73 J4000 'WOOD GO' 360, 2100 MC, T-18, D-20, 60-2 rear, D-44 closed knuckle front, Eaton E-lockers both, Pertronix module, AC, PS, '77 Firebird tilt column, Hydro-boost, AirLift bags front and rear, 33x15 Goodyear MTR's, Pacer 15x8 aluminum Bullet Holes, Summit line lock, 3rd brake light, MileMarker 12,000 cradle mounted winch
Reply With Quote
  #20  
Old 10-26-2011, 10:51 AM
twmattox twmattox is offline
350 Buick
 
Join Date: Feb 24, 2003
Location: Indiana
Posts: 1,282
Rich88, I will give that a try. Never thought of trying it (and should have).

On a side note, I did notice yesterday (while playing around with the choke) that my carb is hot. I mean hot to the point I can't touch it. I am assuming this is not normal? If it is that hot, it would definitely speed up fuel evaporation. I have the phenolic spacer and fiber spacer installed. Not sure why it would be getting this hot.
__________________
'83 Scrambler (CJ-8) / 258 / T-5 / D-300 / DANA 30-AMC20 (3.31)
'88 Grand Wagoneer (SJ) / 360 / TF727 / NP229 / DANA 44 (2.73)
'05 Wrangler Unlimited (LJ) / 4.0L / NSG 370 / NV231 / DANA 30-44 (3.73)
'15 Wrangler Unlimited (JKU) / 3.6L / 42 RLE / NV 241 / DANA 30-44 (3.73)
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Blair Jeep Project III Tatsadasayago General FSJ Discussion 385 12-30-2014 08:03 PM
Carb Needs Primed After Sitting jeepguzzi General FSJ Tech 4 04-18-2009 02:15 PM
Reman 360 - Holley Carb - Way Too Rich JohnIL General FSJ Tech 8 01-23-2008 11:49 AM
New carb and intake how-to. bluesman2a General FSJ Tech 6 12-19-2004 04:30 AM
Fuel bowl empties overnight...Solved!! Jowersgd General FSJ Tech 35 06-02-2004 01:15 AM


All times are GMT -6. The time now is 05:58 AM.


Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
corner corner