253 spluttering and gasping for air

[bigg_vin]

hey people,

i jsut had an exhaust fitted to my car, extractors and all.

when i start her up, she will idle fine, but if i flat foot it when cold, it will splutter and gasp for air, and nearly stall..... and just revs really unevenly, but slowly makes its way to 3 grand, then it will rev smoothly.....

as soon as she is warm, it revs smoothly throughout the rev range with the foot ont he floor.

if the foot is not on the floor, but only graduly pressing the accelerator down, then the problem does not exist....

any ideas what this could be?

i have set the fuel pressure at 4.5psi, and it was not happening before i had the exhaust fitted???

cheers

[253@7k]

Id say your auto choke is rooted.

But foot flat to the floor when shes cold? I think Id get pretty pissed at you too......

[craigvk]

If your choke is working, which it sounds like it is, if you put your foot to the floor when cold, your secondary throttle valves won't open. The secondary valves (wide open throttle) only work when the car is warm, so that's normal.

[SL/ENUT]

Sounds like its letting to much fuel in the carby. So i'll would be looking at the jet size.

[Goon]

Extractors help out with rpm, cooling and fuel flow.

check your timing again for the rpm side of things, i had a similar issue when i installed mine.

Cooling - it will take an extra minute or so for her to warm up.

Fuel - she might be saving on extra fuel atm so she might be getting to much..

Just some areas to look at mate, goodluck

[Smitty]

xtractors eh...?

and she runs like a dog when cold?
my guess....
someone did not refit the warm air tube
that goes from the zorst manifold to the air cleaner
and also probably blocked off the warm air
zorst crossover in the inlet manifold

without them...?
it'll run sick when cold
but
be ok when warm


hth

cheers

[bigg_vin]

ive kinda disconnected the warm air tube cos i was told it is uneccessary pollution gear that just kills your kilowatts!!!

but thanks for the help....

[craigvk]

You can tecnically do without it, because when ever you put one of those chromey air cleaners on, it isn't used. I even have the heat stove on my extractors right now.

[bigg_vin]

i just had a look underneath the car....

on of the bolts on the extractors is loose....

where the two pieces of the extractors come together....

not on the block, but on the y piece.....

the top bolt is loose, and there is no way known to reach it.... the other two on that flange are tight, and there is a heap of exhaust glue/putty innbetween, but the bolt is loose....

i started the car, and sat underneath it, and there is no leak (yet)

[craigvk]

You might need to use a multiple long extension bar and ratchet from inside the engine bay and onto the bolt on the flange, then have a helper with a spanner to hold the nut and then do it up. I had to do that with my exhaust.

[bigg_vin]

yeah, i did try that!

you cant reach it from the top, and even if you could, the nut is sitting behind somethinng, so you wouldnt be able to get a socket onto it...

and then the bolt head is also sitting behind something, so you can even swing a spanner on it....

how would i adjust the auto choke?

[bigg_vin]

oh, and is it usual for a holley blue fuel pump to be rally noisy?
as in hear it over the engine?