'88 Carby starts then dies - (not a fuel line or pump issue)?

[95Compact]

Car was running fine up untill a few days ago.. Now, just to get it started I need to pump the throttle about 3 full strokes. Car starts with a high RPM surge, then immediately dies (2-3 seconds).

Tried already:
- Blew out the fuel lines from pump to tank, pulled the fuel back up the line - no change.
- Removed the fuel filter and replaced with a 'bypass tube' - no change.
- Installed a hose with a funnel directly to the pump inlet, filled funnel, cranked engine. Watched the fuel being sucked in - no change.


Notes:
- It seems that the only fuel being provided is by the acceleration pump.
- Mech fuel pump seems to be working fine (replaced about 1000 mi ago).
- Seems like the main jets are not supplying any fuel.


Questions:
- Does the tank have a return line?
- Does the accelerator pump get its fuel from the line or the bowl?

Any help would be appreciated!

[WmWatt]

I think the fuel return line is just to equalize pressure.
They want to isolate the fuel system from the outside atmosphere
to prevent vapour from contaminating the air people breathe.

Have you coinsidered the automatic choke might be sticking?
Clean and check linkages? Check butterfly valve in carburettor?

[95Compact]

Will check those now, thanks!

[95Compact]

Ok, all free and clear there.

Can't tell if the choke is shutting off though, because the engine won't run to warm up..

[Movin]

The accelerator pump gets its fuel from the float bowl, same as jets. Fuel muck is far more likely to plug jets however, accelerator pumps self clean to a point.

The fuel return line is to keep fuel cooler by constantly bringing cool fuel from the tank through the fuel pump and back. This helps to prevent vapor lock, a common problem with older cars.

[95Compact]

Any way to clean out the jets without disassembling the whole kit and kaboodle? Compressed air somewhere maybe?

I really want to do the Weber conversion, but I just want to check my options before that. This is currently my only (lol) 'running' car!

[WmWatt]

I spray the carburettor with carburettor cleaner once a year when I do the tuneup.
I'm not very knowledgeable but I'd check the vaccum lines.
Also would wet spark plugs mean it's getting fuel and quitting from something else?
Check condition of plugs right after it quits?

[Movin]

If you want a weber I sure wouldn't remove the carb, pull the bowl cover and carb cleaner spray followed with blasts of air to clean all passages and others around the throttle plate. I sure as heck wouldn't check all the vacuum hoses you would remove in a weber conversion for splits, cracks, leaks or down right not hooked up. Then I would put the weber on instead of the OE carb that would likely work fine...


BUT if you have the money those webers rock!

[95Compact]

Thanks y'all, can anyone tell me how to remove the bowl cover?

BTW, there IS fuel in the bowl - I just found the sight glass...

Also, is there any vacuum line problem that could cause the carb to NOT feed fuel from the full bowl to the jets?

[FestYboy]

Thanks y'all, can anyone tell me how to remove the bowl cover?


Also, is there any vacuum line problem that could cause the carb to NOT feed fuel from the full bowl to the jets?

1: YES, remove air box, disconnect fuel line, remove the 2 screws that hold the load comp diaphram (set unit off to side), then there's 2-3 upper vac lines that need removed, then you have 5 screws to take off.
you should empty the bowl first: there are 2 12mm bolts that need removed to empty bowl and access the jets.

2: no vac line can keep the fuel from getting from bowl to jet, the jets are IN the bowl.

[95Compact]

Excellent, thanks Festyboy!

[spoman]

I seem to be having the same problem. I usually turn on the lights or vents just to keep the engine running. However, as soon as I turn those off the engine quits even when it's warmed up. Also I should mention that I rebuilt the carb. It's running better than it was, but I'm still having this problem.

I can't afford a weber conversion so that is NOT an option.

[FestYboy]

spoman, make sure your idle screw is set properly and you don't have a gross vac leak at the base. there are 5 small ports below the primary butterfly that can cause a severe lack of flow signal to the idle and primary jet circuits. it sounds like you have a fuel delivery issue.

[spoman]

I plan on doing some checking this weekend. Seeing as it won't idle without either the vents or lights on, what should the idle be with those running? Or can O set the idle without the engine running i.e. number of turns?

Sent from my DROID RAZR using Tapatalk 2

[FestYboy]

engine must be running to set loaded idle RPM. the loaded RPM is adjusted via a small sprung set screw on the driver side of the carb right below the choke step.

the engine should idle at ~700 rpm at all times no matter what the load excepting that the A/C is on, then you want about 800.