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Re: MGA 1500: Carbs intermittent flooding question

To: "MG List" <mgs@autox.team.net>
Subject: Re: MGA 1500: Carbs intermittent flooding question
From: Steve Morris <smorris@en.com>
Date: Tue, 29 May 2001 13:19:29 -0400
Thanks to all who replied about my carb problem (re-quoted again, below.)

I have the Lucas pump, and it is pumping at exactly 3.5 PSI, so the 
possible overpressure problem that a couple of you mentioned was not a 
problem. Neither were the floats, as they were floating high without any 
gasoline inside. It appears the rear needle/seat was the problem. Both 
were adjusted just right at the 7/16 measurement as prescribed, but the 
rear one must have been stuck.

I took it apart, inspected, cleaned, and re-assembled the float chamber. 
There was a little bit of sediment in the bottom of the bowl, but nothing 
noticeable in the seat. THe float moved very freely on the shaft, and 
there were not any snags to hang up on. Started it up after assembly, and 
it ran just fine. Took it out for a test spin, and about a mile down the 
road, there it started again, but this time it was not intermittent. It 
was pumping out a full flow from the rear float bowl overflow!

I took it apart again, stoned the outside of the float lever (in case it 
was hanging up on the lid), checked the needle/seat again, and put things 
back together. Started fine, and didn't flood. I didn't get to take it 
for a test then, because it was lunch time. After lunch, I went to start 
the engine, and when I turned the key, the pump was clicking away pumping 
gas out the overflow.

Did it all again, but this time I swiveled the fill hoses around so they 
were not pulling so snuggly against the float bowl. Voila! That seems to 
cured things. I've driven it about 30 miles since, and tried to empty the 
bowl (80MPH) and back off quickly to get it to stick, but no 
problems...yet.

Meanwhile, while looking though the A-Antics book for some possible 
solutions, I read about the Grose Jets as a sure cure for the sticking 
needle. Moss catalog and another article seem to recommend them, as well, 
so I ordered a set to give them a try. I also ordered the SU shop manual 
and the carb adjusting kit that was the topic here last week.

So, I seem to be working now, and hope to get the replacements before the 
weekend. If so, or even maybe if not, I can give it a try to get to 
Perrysburg for Edwin's Lake Erie Car Show Sunday!

Thanks again for the help and suggestions,
Steve

>List,
>
>Coming home from Easton last week in Columbus, my MGA was missing on
>occasion. It felt like intermittent fuel starvation. I thought it was gas
>boiling in the bowls while I was in traffic, but it continued out on the
>open road.
>
>I haven't really started digging into the problem yet, but last night I
>was showing my Dad what it was doing, and I discovered a strange symptom.
>I started he car and it ran fine. After a while, when it warmed up, it
>suddenly slowed down and started stumbling. Then after a few seconds it
>would be OK, and then go through this again. Then I smelled gasoline.
>
>I looked at the overflows, and the rear one was squirting gas...then it
>wasn't...then it was, all timed to the stumbling of the engine. It would
>squirt for about 3 seconds, then run OK for about 8-10 seconds, then
>squirt for three over and over.
>
>I know about float adjustment, bad float needle seat, etc., but I can't
>think of anything that would cause this intermittent flooding. Oh, and
>when the key is on and the engine is not running, nothing squirts, and
>the pump is silent.

Steve Morris     Avon, Ohio
1958 MGA 1500    Red/Black
NAMGAR #5987     BuckAyes Ohio Chapter
LoCo Brits       <mailto: MGA1500@mac.com>
http://www.en.com/users/smorris/mga/

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