i think i have a fuel problem

[73series88]

hi
how is everyone
ive just about finished putting my 73 series 88 together
all new ignition
coil
leads
plugs
wires
cap
rotor
points
ht leads
lapped valves new head gasket
good compression
new fuel lines
new pump from rovers
cleaned out tank
new pickup lines
and filters
ok
here we go
i put a second hand weber ich 34 on there
looks very clean but i havent rebuilt it
the only way it will start is if i restrict the intake with my hand and it will start.revs come up for the choke down for the idle.
if i try and rev the motor with the throttle it stalls out on me.
maybe clogged jets?
everything else has been ruled out.
does anyone else maybe have an idea?
thank alot for any help
were down to one car and ive got to get this on the road.
thanks
aaron

[kevin-ct]

Yes, it could be clogged jets or a vacuum leak.

Did you change all those parts to fix this problem?

Kevin

[yorker]

open up the Weber and clean the jets.

[Jeff Aronson]

Oh, boy, this is a tough one to diagnose because you did so much at once before finding this problem, but here goes.

First, please check that you have gapped the points correctly and that the gap is accurate. A lot of poor start/poor running problems are in the ignition.

If the gap is fine, then turn to the fuel issue. Covering the carb intake with your hands implies that you need to enrich the mixture a lot in order to get the car to start. What happens once the car is started? Does it idle correctly once warmed up? In other words, is the starting the only problem?

I assume you don't see any gas leaks anywhere, right?

If you have the single barrel Weber, they do run a bit lean, but they also generally start really well. Is your choke working? When you pull it out, does it close off the carb throat?

If you have a major vacuum leak, then you will encounter the symptoms you describle. Is the carb tight against the manifold? Is the intake manifold tight against the exhaust manifold? Did you install new gaskets? Are the top carb screws tight? Usually, a vacuum leak will also affect acceleration and smooth running.

When the car is running and the choke is off, try spraying WD-40 or PB Blaster around the carb, the intake and exhaust manifolds. If the rpms increase suddently, then you have a vacuum leak, which will cause your starting problems.

The Weber has a mixture screw on the rear, facing the firewall. It is usually turned in until it stops, and then turned out 1 to 1 1/2 turns. It controls the mixture at idle, and if it were completely in, it might starve the carb when it needs it most. If it came off a well running car, then it should not need any adjustment.

The Weber has two jets, one for low speed idle and one for high speed idle. They are accessed by removing the top cover screws, and lifting off the top cover and float as one piece. Look inside the fuel chamber - it should be full of fuel, too. You'll see two tiny brass colored screws at the bottom. Remove them and carefully lift them out. You can spray carb cleaner through them and then screw them back in. There are also jets on the side of the carb facing the valve cover, and on the rear, where the mixture screw is located. If they are clogged, they might affect your starting.

My II-A runs a Weber, and I find that I must pump the acclerator a few times before trying to start the car, especially the first time in the morning. But it does start.

Do you run dry gas in your car this time of year? Carb icing usually affects the car only when you try and accelerate, but it might affect your situation, too.

Those are some thoughts from my experiences with my Rover. Let us know what you find out.

Jeff

[kevin-ct]

Oh, boy, this is a tough one to diagnose because you did so much at once before finding this problem, but here goes.

First, please check that you have gapped the points correctly and that the gap is accurate. A lot of poor start/poor running problems are in the ignition.

If the gap is fine, then turn to the fuel issue. Covering the carb intake with your hands implies that you need to enrich the mixture a lot in order to get the car to start. What happens once the car is started? Does it idle correctly once warmed up? In other words, is the starting the only problem?

I assume you don't see any gas leaks anywhere, right?

If you have the single barrel Weber, they do run a bit lean, but they also generally start really well. Is your choke working? When you pull it out, does it close off the carb throat?

If you have a major vacuum leak, then you will encounter the symptoms you describle. Is the carb tight against the manifold? Is the intake manifold tight against the exhaust manifold? Did you install new gaskets? Are the top carb screws tight? Usually, a vacuum leak will also affect acceleration and smooth running.

When the car is running and the choke is off, try spraying WD-40 or PB Blaster around the carb, the intake and exhaust manifolds. If the rpms increase suddently, then you have a vacuum leak, which will cause your starting problems.

The Weber has a mixture screw on the rear, facing the firewall. It is usually turned in until it stops, and then turned out 1 to 1 1/2 turns. It controls the mixture at idle, and if it were completely in, it might starve the carb when it needs it most. If it came off a well running car, then it should not need any adjustment.

The Weber has two jets, one for low speed idle and one for high speed idle. They are accessed by removing the top cover screws, and lifting off the top cover and float as one piece. Look inside the fuel chamber - it should be full of fuel, too. You'll see two tiny brass colored screws at the bottom. Remove them and carefully lift them out. You can spray carb cleaner through them and then screw them back in. There are also jets on the side of the carb facing the valve cover, and on the rear, where the mixture screw is located. If they are clogged, they might affect your starting.

My II-A runs a Weber, and I find that I must pump the acclerator a few times before trying to start the car, especially the first time in the morning. But it does start.

Do you run dry gas in your car this time of year? Carb icing usually affects the car only when you try and accelerate, but it might affect your situation, too.

Those are some thoughts from my experiences with my Rover. Let us know what you find out.

Jeff

Jeff,

Thats what I said! But, I did it in 10 words!

[Jeff Aronson]

Yes, but I'm hoping I can get paid by the word one day

Jeff

[LaneRover]

Yes, but I'm hoping I can get paid by the word one day

Jeff

Maybe thats how Congress thinks its getting paid . . .

[TeriAnn]

Silly question. Does the Weber need the fuel cutoff solenoid and if one is there or needed do you have a wire going from the solenoid to switched 12V??

I'm rewiring a friend's 88 with Weber and had the same problems you are experiencing until he told me about the solenoid. Getting 12V to the carb instantly solved the running problems. Its an easy one to overlook.

[73series88]

ive just been putting the truck together since august. When i bought it it was just a tub and frame. down in wallingford. no top, floor panels, motor dash was even ripped out the dash. but the frame is in really good shape. 600 bucks on craigslist many orders from host and some very good generous friends. it almost back together.
so all the work ive done to it was just for personal reassurence and relliability. im ordering a rebuild kit for the weber. hopefully that will hash out the running issue. this carb doesnt have the solinoid . is that just a backup fuel shutoff? here are some pics. i'll let you guys know. i havent been this deep in a vehicle since i brought my old mga back from the dead.
creates a real deep bond when your done, you know?
thanks,
aaron

[Tim Smith]

Kevin-CT once told me about a quick cheat if the jets are clogged. I believe it was to rev the motor up and then put your hand over the carb. The vacuum generated might just suck the problematic gunk right through the jets.

I guess this is really a side of the road sort of trick but it might give you some results. Watch out for blow back.

[Jeff Aronson]

It's an old British car trick for SU's, but it does not seem to do much with Webers. I've tried it before and I've always had to remove the jets and spray through them.

I certainly hope it works for you, though!

Jeff

[73series88]

well finished the rebuliding the weber
i noticed when i was putting the adapter plate on
it wasnt sitting strait on the intake.
that round lip was fitting in the plate.
i stacked up some gaskets to try and level the carb.
charging up the battery.
i hope this is it.
aaron

[Jeff Aronson]

If you were sucking in air because the adapter plate did not fit snugly, it would cause some of the symptoms you mentioned in your earlier post.

Good luck!

Jeff

[73series88]

didnt make a difference at all.
carb wasnt dirty inside .
well at least i know the carb is good now.
maybe im having a voltage drop giving me a weak spark
im gonna throw a meter on the pos lead and see where im loosing spark
thinking about getting one of those lucas replacement distributors
does anyone have anything to say about these?
its the last thing i can change out
thanks
aaron

[Jeff Aronson]

The problem you identified first was an unwillingness to start unless you blocked off the carb by hand. Is this correct? Have you ever tried starting it with a brief shot of starting ether? Generally, once the ether is inside the carb throat, it will start if you have any spark at all. If it runs and then dies, you can assume you have a fuel delivery problem.

When you were diagnosing your problem, did you ever remove the carb bowl top plate to see if you had a bowl full of fuel? Ir have you seen fuel in the carb throat?

There's an accelerator pump on the valve cover side of the carb. It has a tiny diaphragm, held in place by small screws. If that diaphragm was bad, you will usually see a gas leak there and it might affect your starting.

Once it started, I inferred that it ran fine. If you had a significant electrical problem, then it wouldn't run smoothly or with power once it started.

Before replacing big pieces like the entire distributor, consider checking its innards first. If you have a new cap and rotor, please check the gap at your ponts. Run an emery board lightly across the points and then gap them again. Does the car start now?

Pull a spark plug and then crank the engine. You should hear a good snap as the plug is held [use insulated pliers] near a ground source like the valve cover. It's an easy way to check the quality of the spark.

A new distributor will make a car with a wobbly distributor shaft run much smoother. You can time it correctly, too, so it obviously run better. I've done it once in my Rover when the old one wore out after a rebuild. So it's not a waste, but I would want to make certain that it's the root of your problem first.

Good luck,

Jeff