Hey everybody.
My first post on this board.
I have tried others that I usually frequent but no one seems to know...so here goes.
I have a 90 Sammi. (still carb)
In the morning when I start it cold it idled up for about 10 sec. than chokes itself to death.
I stinks like raw fuel and idles at 600rpmm or so for as long as I will leave it.
Recently I have held the revs at 3000-3500 to use up the fuel so my kids can sit in er with me without gasping for air. It wont hold an idle, but stalls out.
Once it warms up a bit it will  stall. When I re-start it it idles up to 2000rpm and runs awesome.
Someone suggested the computer(ECM) may be to blame.
I tried shutting it off and restarting to no avail.

Should I try a different ECM?
Will any one work from a Sammi with the puter controled carb?

Anybody recognize this or have a suggestion I would appreciate it.

I would start with the float (fuel) level
in the carb, then check the choke to see
if it's not opening up a little after start, as
the trucklet warms it should open more
and more until it's completly open at running
temp.

After that, if that doesn't work, you may have to
rebuild and or just clean the carb, check for junk
in the needle valve, broken/missing rubber on the
needle, dirt in the bowl, etc.

It ran good once, find what went wrong, it will
run good again

Wild

I'll have a snoop around the carb.

I just wondered if I plugged a different ecm in and it fixes the problem then I would know it was the issue.
If not then I could start messin with the carb.

I am unsure of the intercange between years.

O.K.
I swapped the ECM.
It seemed to idle up well and kick down well, but it was still a bit warm from running it earlier.
I will leave the new ECM in and see if there is any difference when cold.
If not then it is prolly safe to asume that it is carb and not elec.
I will post later as to the results.

If anyone has any other suggestion I am all ears.
Thanks

If not then it is prolly safe to asume that it is carb and not elec.

If it's a Hitachi, it has a water choke.

Another thing to check are the vacuum hoses.  Inspect them carefully as they might break off in your hands if they are brittle.  There are a group of them on the firewall side of the carb that interconnect with the choke system.  They are short and only go to the carb or items attached to the carb.  These might be associated with any warm-up or idle problems -- but then again, any of them tend to screw things up when loose or broken...

Hmmm...never checked the vacuum lines.   

I will try that in the morning.
What do you mean by water choke?
I have never heard that term before.

Thanks alot for the info!   

Engine coolant heats the
choke closer spring

So along the lines of a thermostat, but for the choke?

 

How do I know if mine has a water choke. Or can you tell without dismantling the carb?
Man these are finicky little carbs.

I live in Canada.
I can get pony carbs for 20-30 bucks.
Is this a better option?

You will have a small water line going
to the carb and the coolant flows thru
the area next to the spring, the spring
gets longer with heat, and opens the
choke flap

Pony carbs, I dunno, I'm a EFI guy.

Alright, almost got it.
I swapped brain boxes to rule that out.
Different box, same problem.

I checked all the vaccum lines for correct routing.
I removed the air cleaner assy.
I cold started er and went back to the carb.
After 30 sec. or so it started stinking and was idling at about 600rpm as it always has.
I put very light pressure on the choke plate and it idled up awesome.
Every time I took my finger off the choke it would almost close completely, and back to crappy idle and rich smell.
I put very little pressure back on and let it warm up for 2 or 3 min.
When I took the pressure off it idled and warmed up well.

If only I could get it to do that in the mornin without my assistance.

Should I relace my idle up valve?
How do I know if I have enough vaccum to actuate the valve?
Is there an adjustment somewhere for the choke?

Thanks in advance for any info. on this.

Has anybody experienced this before?

ttt