Engine only runs with starter fluid

[hatepotholez]

Hello everyone, making great progress on the Z. Two weekends ago we got the car running. We used starter fluid to start her up and then light throttle to keep her on.  The week after I buttoned up most of the fuel lines and a quick spray of the starter fluid we got the engine running again and maintained with throttle.

We tried to start it again yesterday and it started up without starter fluid. Yesterday I tried again, no luck, tried starter fluid but stays on then dies even with throttle application.

 

 We are getting fuel at the carbs, I am assuming there is a blockage from the float bowl to the dampers. Also I know for sure the timing is off but I wanted to set the timing with the engine running.

 

Any advice would be greatly appreciated.

 

Thanks!

[siteunseen]

The nozzles maybe too high. Turn the adjustment knob counter clockwise 2.5 turns from the top. They could be stuck, do the nozzles move down when you pull the choke?

They're under the carbs. The hose from the bottom of the float chamber connects to the nozzles on the bottom of the carb bodies.

Sorry I can't show you pics now, on my dumb phone.

[hatepotholez]

The nozzles maybe too high. Turn the adjustment knob counter clockwise 2.5 turns from the top. They could be stuck, do the nozzles move down when you pull the choke?

They're under the carbs. The hose from the bottom of the float chamber connects to the nozzles on the bottom of the carb bodies.

Sorry I can't show you pics now, on my dumb phone.

 

Ok i'll check that out. In the meantime I will look for a SU manual as I am used to Webers.

[siteunseen]

Front carb.  #19 is what I'm talking about.  Tighten it all the way up, then go counter clockwise 2.5 turns for a general setting.  There's TONs of stuff on here about these carburetor.  I think it may have it's own sub-forum?  It does, http://www.classiczcars.com/forum/71-carburetor-central/

 

Whoops, I see your in the forum now. 

[hatepotholez]

Thanks! My buddy tried to remove the float plate, but looks like it won't come off due the main carb having a tab over it? Do I have to remove the carbs off the manifold to get access to the float chamber?

[Mark Maras]

Nope The float chamber is alongside the carb body. The fuel enters into the top of the float bowl. 3 or 4 screws & probably a new gasket.

[siteunseen]

I think you are talking about the metal "bracket" (used for lack of the correct word) that has to be bent down around the fuel inlet on top.  You can take the screws out like Mark says and that bracket will be loose, lay it off to the side and gently pry the lids off, probably still tearing the one use gaskets.     

 

Here's a picture of what I'm talking about, it's called a brace.  The big bolt with the internal fuel filter goes through it.  Bottom right corner of this picture is the thing that has to be bent to loosen the banjo bolt.  Probably confusing you more as I'm no good at explaining, sorry.

 

Get the DVD "Just SUs" from Z Therapy, it's a must if you've got SU carburetors that you want to work on. 

[hatepotholez]

Thanks guys, i'll take a video and photos to explain more.

[hatepotholez]

Ok the plot thickens, I have or(had) gas coming out of the float tube going to the nozzle. This is exactly where the fuel stops. No fuel comes out of the nozzle under the dampers, bone dry. Took apart the front carb, looked decent and set the float. I followed the service manual and back out the fast idle screw and balance screws and then tightened and turned back the nozzle adjusting screw by 3 turns based on ambient temps, I also then put 2 more gallons of gas, I have at minium 4 gallons of gas.

Next step, used carb cleaner to the nozzles, there was no blockage.

Then attacked the fuel pump. I disassembled the fuel pump which was dirty but nothing looked clogged, and put it back together. I then removed both hoses off the fuel pump and put my fingers over them and felt no suction.

Ill try and rebuild the pump and replace the internals with new parts or get a new pump.

[hatepotholez]

I should add that before I dissasembled the fuel pump my fuel filter never passed the halfway mark, now its at the 25% mark. I beleive the fuel filter should be full at all times?

[beermanpete]

How much fuel is visible in the fuel filter in not important, nor is it a reliable indicator of fuel flow. Try using a remote fuel tank to run the car via gravity feed to the carbs. If it runs then you know the carbs are ok and the problem is the pump or a problem in the fuel line somewhere.

[siteunseen]

Is it a mechanical pump or electric?  If it's mechanical you won't feel much air just turning the motor with the starter. 

 

Those little hoses have to be just right or they'll kink and you'll have no flow between the float chamber and the carb.  My red 240 had some rock hard 1/4"? fuel line on those carbs that wouldn't let the nozzles move down.  Hard to start.

 

I did what Beerman says, put a 2 gallon plastic gas jug in front of the radiator and ran the 2 lines into that and the car ran fine.  Then dropped the gas tank and cleaned all the crap out.

 

When I bought mine the valves were so far out of adjustment it took forever to start.  Set them and then it would start as soon as I turned the key.