After The Cam Swap

[malc]

Now itīs all back together and the new oil temp sender is in the car runs and drives just great.

BUT.......

On cold startup it coughs, farts and splutters, the vac gauge needle fluctuates wildly then as
I peddle it, it starts to run properly and settles down to idle at 800rpm.
I set the initial at 14 BTDC as Edelbrock recommended, the mixture screws are one turn out,
fuel pressure is 4.5.
Once the motor is warmed up it re starts no problem.

Where do I look first to get this sorted ?

[cstmwgn]

Malc - sorry if I haven't been paying attention. Are you saying that all your grief has been around some odd ball timing chain setup / specs that are specific to Edelbrock's parts?

As to your question - what type of choke do you have? It sounds from a far distance that the choke isn't giving it enough richness to compensate during cold start up. Also the fuel pressure seems a tad low BUT I don't believe it is causing your cold start running issue.

[malc]

More or less.....things did get better after buying Edelbrocks "recommended" chain.

I've got a 750 Speed Demon vacuum secondaries
and electric choke.
My mode of starting is to press pedal which closes the choke another to squirt some fuel and
crank.
I know the choke closes as I can see it from inside the car.

[cstmwgn]

so how many pumps of the pedal when cold?

If you are only pushing it down one time you might try a few more pumps. On my stuff 3 or 4 pumps does a good job of getting enough fuel in the manifold. Can you tell is there is any black smoke on start up? From your description it sounds lean so a few more pumps might help.

[Deaf Bob]

Qjet on flatbed needs rebuilding.. Crank, pump then crank to start..
Colder days may take several tries..

[silver_bullet]

IIRC, 6-7 psi is what you need at idle for a demon based carb....

[malc]

Just had a look at my carb's instructions.......
setting fuel pressure to 6psi later today..
and see what happens.

[anotheridiot]

if its choking, caughing and hacking there is already too much fuel to the air its getting. Sounds like the butterfly needs to be adjusted to be a little closer to opening.

[malc]

I've set fuel pressure to 6.5.

Worked on the mixture screws and got a steady 15" at idle.

Iīll set the choke to give it some more air.....tomorrow, motor is still hot.

[DanStokes]

if its choking, caughing and hacking there is already too much fuel to the air its getting. Sounds like the butterfly needs to be adjusted to be a little closer to opening.

I wonder if a Muscinex in the tank would help (I'm useless at tuning stuff so I take it to the dyno shop).

Dan

[malc]

Don't you mean Mucinex ?
If so.....we ain't got that here.
So do you go to the dyno or pharmacy ?

[malc]

I set the choke this morning to be a tad more open, it was virtually
closed shut.
Start up went a whole lot better and itīs getting better to drive with use.
The idle is really lumpy but it changes as I get over 1500rpm, it smooths out and
pulls hard.

Itīs almost like having a new car.

Next up will be the installation of my 1.6 rockers.

Then itīll be the two piece timing cover and maaaaybeee advance the cam 4š.

Iīve also got an air/fuel ratio gauge to go in......

and a speedometer to fix, hoping itīs just a broken cable.

[anotheridiot]

I set the choke this morning to be a tad more open, it was virtually
closed shut.
Start up went a whole lot better and itīs getting better to drive with use.
The idle is really lumpy but it changes as I get over 1500rpm, it smooths out and
pulls hard.

Itīs almost like having a new car.

Next up will be the installation of my 1.6 rockers.

Then itīll be the two piece timing cover and maaaaybeee advance the cam 4š.

Iīve also got an air/fuel ratio gauge to go in......

and a speedometer to fix, hoping itīs just a broken cable.

I hope you can stop after that new car thought and enjoy it for a while.

[malc]

I hope you can stop after that new car thought and enjoy it for a while.

Thanks for pointing me in the right direction..

[Loren]

The heavy mechanical stuff will surely make incremental improvements but if it were me, I'd do the O2 sensor and speedometer instead for now, just for interest. Take a break from the other for a bit, after all that.

Or not...

Am I helping?