New Weber 45, Fuel in but none out?
Thread Starter
Joined: Nov 2006
Posts: 8,482
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From: Huntsville AL
New Weber 45, Fuel in but none out?
So I got the car all buttoned up after many months. Got spark, got fuel, and of
course air. I turned the car over with no spark for about 15 seconds to get oil
pressure up beforehand and fill/semi-lube the combustion chambers. After all is said
and done, I turn the spark on and begin to crank. And crank. And crank. Nothing.
Not even a wheeze! So I set my engine to TDC, set dizzy to TDC and check for
spark. All checks out. Crank crank crank, nothing still. The MSD makes the spark
plugs sound pretty cool though, but that is beside the point
Pull the plugs and they are dry as a bone. Interesting, this leads me to
carburetor. I pull the lid off the Weber 45DCOEm and sure enough, there is fuel in
there. Check the E-Tubes and they are wet as well. I go to the back of the carb
and turn the adjustment screws so they gently bottom out, then crank out 1.5
turns.
Crank crank crank, nothing. Dry.
Any ideas? I am searching as we speak and looking in the weber tuning handbook
as well.
course air. I turned the car over with no spark for about 15 seconds to get oil
pressure up beforehand and fill/semi-lube the combustion chambers. After all is said
and done, I turn the spark on and begin to crank. And crank. And crank. Nothing.
Not even a wheeze! So I set my engine to TDC, set dizzy to TDC and check for
spark. All checks out. Crank crank crank, nothing still. The MSD makes the spark
plugs sound pretty cool though, but that is beside the point

Pull the plugs and they are dry as a bone. Interesting, this leads me to
carburetor. I pull the lid off the Weber 45DCOEm and sure enough, there is fuel in
there. Check the E-Tubes and they are wet as well. I go to the back of the carb
and turn the adjustment screws so they gently bottom out, then crank out 1.5
turns.
Crank crank crank, nothing. Dry.
Any ideas? I am searching as we speak and looking in the weber tuning handbook
as well.
Joined: Mar 2001
Posts: 31,837
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From: https://www2.mazda.com/en/100th/
it might just be really lean. i'd squirt a little brake clean in the carb, and see if it fires.
cold engine needs a lot of fuel to start, but not as much to stay running
cold engine needs a lot of fuel to start, but not as much to stay running
Thread Starter
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
fuel is on the plugs. I don't want to turn it over much longer. The thought of metal
on metal with no lube sends chills up my spine.
I just blew a little bit of air where the needles seat at, and it came out in the E-tube
area, so I know that atleast some air can get through it.
Thread Starter
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
So I got someone to crank the car as I stood outside and covered the velocity stacks with my
hands. After about 3 turnovers she kicked and sputtered and I told him to stop turning it over.
Fuel came pouring out of the stacks. This has me thinking that the main circuit is working, but
the idle isn't?
EDIT: She started up when I cranked her again, but only ran for about 4 seconds. I believe
that was from the gas that poured out of the velocity stacks getting sucked in a bit. Still nothing
after cranking
hands. After about 3 turnovers she kicked and sputtered and I told him to stop turning it over.
Fuel came pouring out of the stacks. This has me thinking that the main circuit is working, but
the idle isn't?
EDIT: She started up when I cranked her again, but only ran for about 4 seconds. I believe
that was from the gas that poured out of the velocity stacks getting sucked in a bit. Still nothing
after cranking
Last edited by Jeezus; Apr 19, 2010 at 06:18 PM. Reason: More Info
Joined: Mar 2001
Posts: 31,837
Likes: 3,234
From: https://www2.mazda.com/en/100th/
So I got someone to crank the car as I stood outside and covered the velocity stacks with my
hands. After about 3 turnovers she kicked and sputtered and I told him to stop turning it over.
Fuel came pouring out of the stacks. This has me thinking that the main circuit is working, but
the idle isn't?
EDIT: She started up when I cranked her again, but only ran for about 4 seconds. I believe
that was from the gas that poured out of the velocity stacks getting sucked in a bit. Still nothing
after cranking
hands. After about 3 turnovers she kicked and sputtered and I told him to stop turning it over.
Fuel came pouring out of the stacks. This has me thinking that the main circuit is working, but
the idle isn't?
EDIT: She started up when I cranked her again, but only ran for about 4 seconds. I believe
that was from the gas that poured out of the velocity stacks getting sucked in a bit. Still nothing
after cranking

Dreamin of drivin my 7!
iTrader: (18)
Joined: Feb 2009
Posts: 1,073
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From: Seabeck, Washington
If you are pumping the throttle, even if the idle jets were somehow clogged, you'd be getting the "main" shot when the butterflys opened. What's the fuel pressure at the carb? Check the pump jets and be sure they aren't clogged or "bound". If you have a compressor, put the blow attachment on and pull the top cover, blow out all, the jets and tubes, then press the tip to each hole in the carb body and verify that air is passing through where it should.
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Have you checked to make sure you get a nice blast of fuel when you open the butterflys? If not might be a bad accelerator pump. If you have other jets try some others in the event you have something plugged in your current ones. Idle jets in particular. Also try opening your idle skrews out 2 full turns. Give her 10 full pumps and turn over without any gas.
IN my experiance no matter how poorly your weber is jetted, as long as you have fuel you should get it to at least kick over.
IN my experiance no matter how poorly your weber is jetted, as long as you have fuel you should get it to at least kick over.
Thread Starter
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
Fuel pump works, fuel pressure is at 3psi. I have fuel in the floats, but as far as I know that is
as far as it can get. I'll give it another go tomorrow and pick up some carb cleaner.
as far as it can get. I'll give it another go tomorrow and pick up some carb cleaner.
You got some varnish built up in one of those small tubes. You may want
to pull it apart and clean it real good. If it sat for 6 months with no movement
its likely gummed up some passage.
to pull it apart and clean it real good. If it sat for 6 months with no movement
its likely gummed up some passage.
Joined: Mar 2001
Posts: 31,837
Likes: 3,234
From: https://www2.mazda.com/en/100th/
Thread Starter
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
yesterday when I tried to crank it over.
I pulled all the jets out and blew through them. The idle jets looked wet inside, but
not on the outside like the mains are. I blew some more air where the E-Tubes go
and got a face full of gas (this was after I drained out all the gas). I have no way to
get the carb off the manifold, it is held in by allen bolts that I can't get to with my
set.
Carb was rebuilt and prepped before I got it. Never put any gas into it until
yesterday when I tried to crank it over.
I pulled all the jets out and blew through them. The idle jets looked wet inside, but
not on the outside like the mains are. I blew some more air where the E-Tubes go
and got a face full of gas (this was after I drained out all the gas). I have no way to
get the carb off the manifold, it is held in by allen bolts that I can't get to with my
set.
yesterday when I tried to crank it over.
I pulled all the jets out and blew through them. The idle jets looked wet inside, but
not on the outside like the mains are. I blew some more air where the E-Tubes go
and got a face full of gas (this was after I drained out all the gas). I have no way to
get the carb off the manifold, it is held in by allen bolts that I can't get to with my
set.
clean it then, being very careful not to ruin any gaskets.
I use star sockets on an extension to get allen screws out all the time.
Usually one of the star sockets will fit the allen head really well and I just
put it on an extension and use my rachet to get it off.
They look like this:

What kind of manifold is it on?
Thread Starter
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
Oh you left that little tidbit out. So I would take it completely apart and
clean it then, being very careful not to ruin any gaskets.
I use star sockets on an extension to get allen screws out all the time.
Usually one of the star sockets will fit the allen head really well and I just
put it on an extension and use my rachet to get it off.
They look like this:

What kind of manifold is it on?
clean it then, being very careful not to ruin any gaskets.
I use star sockets on an extension to get allen screws out all the time.
Usually one of the star sockets will fit the allen head really well and I just
put it on an extension and use my rachet to get it off.
They look like this:

What kind of manifold is it on?
I have taken the top off, pulled both idle and main tubes and blew through them.
Also compressed air the holes they went to, removed all the screw holes in the
back for the accel pump/progression/needle and made sure they were all clean. I
am drawing a blank here on where the fuel ends at. I might get some food
coloring and drop it in the float bowl and see where the color comes up at.
Thread Starter
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
Finally got her running! Got Rob from Rotaryshack on the phone. Ended up taking out the accel
pump jets and she fired up. Sounds like it is running off of one rotor, and the thermostat is
stuck as well (took cap off radiator and no bubbles, turned car off after temp needle got about
1/3 way up). She won't stay below 2.2k, or else she starts to slow and stall out. Tried calling
Rob back but he is a busy man
pump jets and she fired up. Sounds like it is running off of one rotor, and the thermostat is
stuck as well (took cap off radiator and no bubbles, turned car off after temp needle got about
1/3 way up). She won't stay below 2.2k, or else she starts to slow and stall out. Tried calling
Rob back but he is a busy man
Dreamin of drivin my 7!
iTrader: (18)
Joined: Feb 2009
Posts: 1,073
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From: Seabeck, Washington
If you are pumping the throttle, even if the idle jets were somehow clogged, you'd be getting the "main" shot when the butterflys opened. What's the fuel pressure at the carb? Check the pump jets and be sure they aren't clogged or "bound". If you have a compressor, put the blow attachment on and pull the top cover, blow out all, the jets and tubes, then press the tip to each hole in the carb body and verify that air is passing through where it should.
Thread Starter
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
Thought thats what it might be. Glad you sorted it out. those pump jets fit really tight at times, and can be overtightened or blocked on install ocassionally. Also can be a pain to get out. Sometimes they get put in upside down too. there's a small "ring" around the top, which makes for easier removal and identity. When you pulled them, was the ring on top?
removed the accel jets, and replaced the cap. That is what got the car started. I put
them back in now but tightened it to where the o-rings touched, then half a turn
more.
Did some more tuning on it today, it seems something is funky with the rear rotor.
The front rotor's needle can be backed off to about 3 turns out, but the back's
needle can go all the way down and up and no difference.
Thread Starter
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
Is there any way that these screws can be screwed down far enough to stop the A/F mix from
going past it?

Reason I ask is because the front barrel had this screw semi-loose and the rear was tight.
going past it?

Reason I ask is because the front barrel had this screw semi-loose and the rear was tight.
I hate to say this, but it sounds like the carb needs to be rebuilt. If you can get it apart without damaging the gaskets, bring it to me and I can drop it in my carb cleaner for ya.
Dreamin of drivin my 7!
iTrader: (18)
Joined: Feb 2009
Posts: 1,073
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From: Seabeck, Washington
Those appear to be the progression holes screw covers. Some webers don't even have the screws there. Take them out and look inside, there should be a few holes in the bottom. Make sure they aren't clogged.
Thread Starter
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
So I did a test to see if I was getting fuel or not. I took the progression hole screw cap thing off,
and grabbed a freezer zip loc bag. I placed it over the hole while the car was running, and
sure enough, I could see some fuel going through it and into the progression holes. I need to
do this on the needle part, to see if it is getting there. I am 99% sure it is since I stuck a pipe
cleaner through the hole between the needle and progression, and could see the pipe
cleaner inside the needle area.
I also started it up and got it running at about 2500rpm, then cut the ignition off to check to
see if I was getting any fuel on the plug. Both plugs were equally damp. I have air... seems
like I have fuel... so I checked spark. Pulled the leads off the front and rear plugs and tested
the leads. Got good spark. Even pulled the spark plugs I was using and they showed nice
sparkage.
This has me thinking, could I have a weak ground on the rear housing? There was a ground
strap that originally ran from the strut tower to the rear Iron/transmission, and I snipped
that off. Never replaced it because I hate wires, but if I need it to run I can see if I can find
something to throw on there.
and grabbed a freezer zip loc bag. I placed it over the hole while the car was running, and
sure enough, I could see some fuel going through it and into the progression holes. I need to
do this on the needle part, to see if it is getting there. I am 99% sure it is since I stuck a pipe
cleaner through the hole between the needle and progression, and could see the pipe
cleaner inside the needle area.
I also started it up and got it running at about 2500rpm, then cut the ignition off to check to
see if I was getting any fuel on the plug. Both plugs were equally damp. I have air... seems
like I have fuel... so I checked spark. Pulled the leads off the front and rear plugs and tested
the leads. Got good spark. Even pulled the spark plugs I was using and they showed nice
sparkage.
This has me thinking, could I have a weak ground on the rear housing? There was a ground
strap that originally ran from the strut tower to the rear Iron/transmission, and I snipped
that off. Never replaced it because I hate wires, but if I need it to run I can see if I can find
something to throw on there.
Thread Starter
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
Well, fustration leads to action, and I made a ground strap up. Used the old negative cable
and cut a good length off and grounded the top inspection cover to the nut holding the
heater core inlet on the firewall. Good news, it will keep its idle (may have been because it
was warm) if it stays around 1500ish. When it was warming up it would rev higher to about
2200 then slowly start to stall out and chug for a few seconds, then back up. After it stayed
around 1100ish warm, I thought to my self, screw it. It runs.
So I took it out for a test drive. It hates driving below 2400ish RPM, but then it starts to clean
itself up ( I assume because I am now on the main circuit) when I put some load on it. Got to
the end of the street and turned to the main road and it would load up as soon as I got
above 4k. Then I started to get a guy in a nissan following me. How was I to know it was
shooting 6 foot flames out the back?
He stopped when I parked and asked about the
car. Turns out he has a yellow SA with a TII motor in it, just needs the haltech thrown
together to get it running
and cut a good length off and grounded the top inspection cover to the nut holding the
heater core inlet on the firewall. Good news, it will keep its idle (may have been because it
was warm) if it stays around 1500ish. When it was warming up it would rev higher to about
2200 then slowly start to stall out and chug for a few seconds, then back up. After it stayed
around 1100ish warm, I thought to my self, screw it. It runs.
So I took it out for a test drive. It hates driving below 2400ish RPM, but then it starts to clean
itself up ( I assume because I am now on the main circuit) when I put some load on it. Got to
the end of the street and turned to the main road and it would load up as soon as I got
above 4k. Then I started to get a guy in a nissan following me. How was I to know it was
shooting 6 foot flames out the back?
He stopped when I parked and asked about the car. Turns out he has a yellow SA with a TII motor in it, just needs the haltech thrown
together to get it running
Thread Starter
Joined: Nov 2006
Posts: 8,482
Likes: 31
From: Huntsville AL
TTT
Got a bucket of carb cleaner. Took the stacks off and e-tubes out and dunked it in. Hopefully
this time tomorrow it will have whatever junk inside the carb come out.
Got a bucket of carb cleaner. Took the stacks off and e-tubes out and dunked it in. Hopefully
this time tomorrow it will have whatever junk inside the carb come out.






