Carburetor Issues

[cooprasupra]

I am currently at a head scratching standstill getting my truck to run. I have installed a Weber 32/36 and I am pretty sure that is what the problem is at this point. After many searches for my symptoms I have came up empty handed.

 

What happens is when it turns on the electric choke engages and revs high but then it revs really high and will not come back down. When I hit the accelerator it slows down the rpms but as soon as I come off it takes back off.

 

This even happens when the idle set screw is backed all the way out.

 

I just adjusted my float level because prior to this it would shut off the fuel and bog down and die. 

 

Any advice would be greatly appreciated.

[Lockleaf]

Have you disconnected the choke wire, or jammed the choke open to see how the engine runs off choke?

[cooprasupra]

Have you disconnected the choke wire, or jammed the choke open to see how the engine runs off choke?

 

Yeah, I disconnected the electric choke and same thing persists.

 

Perhaps this could be distributer related?

[banzai510(hainz)]

sure the cable is slack????????

 

distributor to far advance might give a higher idle.

 

 

make sure the 2nd barrel is closed Theres a spring to keep it closed but usually this makes it not idle.

 

 

when one swaps to a weber the weber needs a helper spring for the cable

[datzenmike]

Not distributor related.

 

 

Throttle cable too tight?

 

Fast idle cam sticking? Spray the linkages above the throttle shaft liberally with carb cleaner or WD-40.

 

Secondary barrel is not fully closed. Use a flashlight and look down it.

 

BCDD not shutting off. Pull rubber cover plug off and turn adjustment screw Counter Clockwise to reduce sensitivity.

[cooprasupra]

sure the cable is slack????????

 

distributor to far advance might give a higher idle.

 

 

Not distributor related.

 

 

Throttle cable too tight?

 

Throttle cable is loose. 

 

I will look into the idle cam.

 

When I say this thing is running high RPM I really mean super high.

 

Would it be a possibility that if the timing chain is off a bit that it could cause this? Just trying to narrow down.

[Lockleaf]

Please answer all of the following questions.

 

What engine are you running?

 

Was the truck running on the old carb? How well did it run?

 

why did you switch to Weber?

 

Is this a new or used Weber?

 

Have you done ANY other engine work in the recent past? If so, what did you do?

 

These answers, as clear as possible, will help us help you.

[racerx]

don't think it's your timing chain. When you say high RPM, how high?

[cooprasupra]

Please answer all of the following questions.

 

What engine are you running?

 

Was the truck running on the old carb? How well did it run?

 

why did you switch to Weber?

 

Have you done ANY other engine work in the recent past? If so, what did you do?

 

These answers, as clear as possible, will help us help you.

 

Surely.

 

Truck has an L16, it was not running on the stock carb. Head gasket recently blew when initially trying to get it run.

 

We tore the motor down and had the head machined and reworked. Threw the Weber on as the old carb was too damaged to use and I could not find parts.

 

We replaced all gaskets and installed a new fuel pump as the old one was not working. 

 

Yesterday the truck had the same symptoms except it would eventually die. I adjusted the float level and now I am stuck with the issue however it does not die anymore.

[cooprasupra]

don't think it's your timing chain. When you say high RPM, how high?

 

I do not have a tach but it is insane, if I had to guess I would say 8k. It sounds like it thinks it is under load.

[Lockleaf]

Used Weber or new?

[racerx]

First, get a tach., very cheap or buy a tach/dwell meter.  When warming up my tach is a little below 2K and have a 32/36 manual choke weber.  At this point, you are not sure how high is high.

[banzai510(hainz)]

Is weber old or new?

 

I assume the motor is timmed correctly. YOu can see my You tube vid on how to install the oil pump /distributor drive to get it close.  look up:Hainz Datsun L series and it will pop up.

 

 

put motor on TDC and ck the cam timming then the dist timming.  If used carb then it has to be the carb. Even if off a tooth I dont think it will do this(high idle)   does the butterfly/flap look bent?

 

Really you dont need a Tach  I dont have one on my 3 datsuns.

[cooprasupra]

Is weber old or new?

 

I assume the motor is timmed correctly. YOu can see my You tube vid on how to install the oil pump /distributor drive to get it close.  look up:Hainz Datsun L series and it will pop up.

 

 

put motor on TDC and ck the cam timming then the dist timming.  If used carb then it has to be the carb. Even if off a tooth I dont think it will do this(high idle)   does the butterfly/flap look bent?

 

Really you dont need a Tach  I dont have one on my 3 datsuns.

I am fairly certain it it timed correctly. The chain did slip when I put the cam back on even though I used a wedge. It seems to be pretty agreed upon that you can't get the chain back on the tensioner correctly without removing the timing chain cover but I did get it on. Nonetheless even if it is off time it should not idle this high from what I read.

 

It is a new Weber however it sat for about a year with dirty gas in it. With that being said I cleaned the hell out of it and made sure the jets were clean and fine. Butterfly does not seem bent. I guess first order of business is to check the little cam on the carb.

[kelowg]

Without choke wire connected to switched 12 volt source,choke WELL NOT DISENGAGE. Power to choke heater makes choke butterfly open. sticking carb linkage is fairly common. bell crank nut over tightened can cause sticking too.

[Rick-rat]

Have you checked for vacuum leaks?

[mrbigtanker]

You do have a good return spring right.

[datzenmike]

High RPM is subjective without a tach. Normal fast idle on an L carb is 1,800 to 2,200 and it sounds like it's going to to blow but it's nothing. Without a tach and hard numbers revving to 8k is meaningless.

 

 

For the engine to rev up you need gas and air. That's it. The cam isn't going to do this nor the distributor or the timing chain or the ignition timing.

 

Next time it revs up shut it off and look down the primary and secondary barrels.

Already asked about this....

 

 

Secondary barrel is not fully closed. Use a flashlight and look down it.

 

 

 

It should be fully closed.

 

Primary should be almost closed, hardly even noticeably cracked open.

[Charlie69]

It is a new Weber however it sat for about a year with dirty gas in it. With that being said I cleaned the hell out of it and made sure the jets were clean and fine. Butterfly does not seem bent. I guess first order of business is to check the little cam on the carb.

 A new Weber has not sit on a shelf with gas in it for a year!

[banzai510(hainz)]

maybe the dist is install a tooth advanced??????????????

 

 

I dont think a year gas sitting is going to kill it as I go 6months not starting my car.

 

Its something simple. I Lay money on it

 

 

show us the Cam timming and the dist spindal with the distributor removed at TDC

[DanielC]

A lot of gasoline sitting in a tank probably is OK.   A carb sitting with a float bowl full could be a problem, because some of the gas will evaporate, and leave a gummy residue in the bottom of the carb, where the jets, and feed to the accelerator pump are.

[datzenmike]

Some back story.... the head was removed and the tensioner fell out. Cam timing is now suspect and should be confirmed as correct. UNLESS it was running properly between the timing chain setting, and installing the weber.... then it would be the weber.

 

 

High revving won't be the cam. Something is letting in more air and gas.

 

Did you look at the throttle plates??? are they stuck open?

[cooprasupra]

Noticing today that if I cover butterfly with my hand it significantly slows the idle down and while a little rough sounding it seems to be idling ok.

 

Guessing vacuum perhaps, unfortunately I am not sure where to go from here.

[Roadster-ka]

Take carb off, turn it upside down and locate what is keeping throttle from closing!

[Rhino13]

I installed a sync link kit on my 32 36 and the secondary linkage was welded slightly off and holding the secondary butterfly open causing it to idle at 3000 rpms. Its already been said, but you have air getting in somewhere causing this. Which vacuum lines do you have hooked up or capped off? Did you use a new adapter or used? Did you use all fresh carb gaskets? Are your fittings on the manifold tight? Are you using the manual fuel pump or an electric? And you were saying it won't idle now, if you keep your foot on it can you keep it running? And if so where does it cut out? (Obviously a rough estimation since you don't have a tach)