Aceca Stalling at Stops

[pjbowman]

My AC engined Aceca has developed a nasty habit of stalling when I come up to a stop sign, or any other type of stop from a run. If I blip the throttle a few times to prevent this it will settle into it's idle, but can't always do that between braking and down shifting. I've got plenty of fuel, have set the idle speed up some, but nothing seems to help. Any chance it's a weak fuel pump? Any other ideas? Runs fine when I'm just driving.
   
   Peter B.

[Gus Meyjes]

When the engine is not fully on temperature I have the same thing. Did not think much of it, as it goes away when warm. Takes a long time to get it to fully warm up.
   
   Gus

[pjbowman]

Thanks Gus, mine does it even when fully warm, that's what's puzzling.
   
   Peter

[tinnes]

Peter - a couple questions and a wild hare -
   
   Does the engine idle OK when started from cold? How about when re-started while still hot?
   
   Is it possible that this is an electrical problem, e.g. a bad/resistive connection that lowers the effective voltage  to the fuel pump? When you increase throttle the effective voltage to the pump would also increase.
   
   When starting from cold, the idle speed may be just higher enough that the fuel pump can do its job. What happens if you simply let the engine idle for several minutes until the starting carb shuts off?
   
   I did say it was a wild hare - good luck!
   
   tom i
   AEX456, BE772

[AC Ace Bristol]

quote:Originally posted by pjbowman
   
My AC engined Aceca has developed a nasty habit of stalling when I come up to a stop sign, or any other type of stop from a run. If I blip the throttle a few times to prevent this it will settle into it's idle, but can't always do that between braking and down shifting. I've got plenty of fuel, have set the idle speed up some, but nothing seems to help. Any chance it's a weak fuel pump? Any other ideas? Runs fine when I'm just driving.
   
   Peter B.
   

   
   
   Peter
   
   Just a thought,  If the engine wont idle on tick over and often stalls, check you carburettors to see if the idle jets need cleaning, A simple test squirt some WD40 near each carburettor does the engine suddenly pick up ??
   
   This will also indicate if you are drawing in air due to non sealing gaskets on the inlet manifold.......
   
    Just a thought,
   
   Keith

[pjbowman]

Keith/Tom - thanks guys. The car idles fine under normal circumstances - it's only when coming to a stop that it stalls. It will fire right up again. I'm getting a fuel pressure gauge and will see what kind of pressure the fuel pump is putting out - I have my suspicions it's somehow not up to the job. Keith, I'll try your suggestion too, and will let you guys know what I find out (if anything). Thanks for the suggestions!
   
   Peter

[aex125]

Peter,
   Have you checked you float levels? The symptoms sound like the idle circuit might be getting uncovered by your braking action. I have to admit I am not familiar with the AC engined SUs, but have heard of similar problems on other SUs with low float levels so there might be a connection.
   Jay

[pjbowman]

I'll check them Jay, in case one(or more) of the floats may be partially flooded or something. Good suggestion! Now I have my weekend project all lined up. Also bought a fuel pressure gauge last night, so I'll see what kind of pressure I'm getting and compare to my Ace which has no such stalling problems.
   
   Thanks as always.
   
   Peter

[pjbowman]

Haven't had much time to follow up, but I did fit the fuel pressure gauge, and got a solid reading of 2psi, so that doesn't look to be the issue. I still need to check the floats to see if one or more may have a leak, so that's next. will report back on any findings!
   
   Peter B.