Carb trouble

[stock93]

I have a 250 inline 6 with a 2se carb on it. I recently rebuilt it. My engine wants to die when coming to a stop. I already replaced the vacuum brake booster check vavle. It only does this while in motion. If I'm sitting still I can hit the brakes and the rpm doesnt drop. At this point I'm at a loss. Theres no trash in the carb. I know the float level is set correctly. I dont think I have a vacuum leak. It runs good otherwise. The only thing I've noticed is occasionally the idle will go up to 1200-1300 on its own.

John

 

[pvfjr]

I know nothing about your carb, but your choke pull off may not be set right.

 

[diesel4me]

2SE huh---good luck!

I've had several of those "camelhumper" 6's with the 2SE carbs...one was on my 81 G10 van,that carb drove me batty--despite rebuilding it,cleaning it,setting the float perfectly,I could never get rid of the hesitation it had while accelerating--tried new accelerator pumps,etc--still acted up--but not all the time!--some days it ran perfect... --I eventually put a 307 V8 in it instead(not much better,but thats another long story! )...

The other ones I had liked to stall too,like yours is doing--I even had a carb "guru" with an excellent reputation and all the right angle gauges go thru it,and it still would not idle right most of the time..I decided the 2SE carbs were just a POS,as everyone I asked about them said they were...I sold that motor to a guy who needed a straight 6,and I put a V8 in that truck as well..

The latest one I had was in my 79 C10,it had a 250 six with the 2SE carb--as soon as I got the truck,I removed it,even though this one actually ran very well--I just didn't want to deal with any more 2SE's after the last two I had--I even considered swapping an older head on and using a one barrel carb!-I ended up adapting an Edelbrock performer onto it with a homemade adapter plate,and disconnected the rear"secondary" barrels by taking the linkage off--

It ran very well for nearly 2 years,then at 116,000 miles, the #6 piston lost a chunk off its head,exposing the top rings--barely made it 15 miles home,and it smoked like a SOB,and the motor was rapping when I got it home --used nearly all the oil...now it has a 305 V8 in it--and its like a whole new truck as far as power,and the fuel mileage actually improved(using the same 600 CFM Edelbrock I had on the 250!)....

I wont say to swap to a V8,but its not a bad idea!--I still have the 2SE carb,and the air cleaner off the 79 C10's 250 if your interested in it--its been off and sitting in my shop for 3 years,but it did work good when removed...PM me if your interested--I junked the motor,and have no use for it.(not that I ever would anyway! had enough of them)..I'd rather see someone use it,than let it sit and rot,or toss it away...its probably the only one that ever worked right!...

 

[diesel4me]

just thought of something...

Your 250 might have an "internal" vacuum leak!--I noticed the ehaust manifold unbolts from the intake ,even though the intake is casted "integral" with the cylinder head--and there is a stainless steel gasket between them,the only thing that separates the exhaust from the intake passage directly under the carb..this area looks like a "bulls eye" pattern in the steel gasket--its function is to "pre heat" the raw fuel being dumped into the intake,to give better mileage and performance--any leaks in that gasket will allow exhaust to enter the intake,which dilutes the air fuel mixture,like a vacuum leak does,only worse because its already burnt gasses going in instead of fresh air!-...

The EGR valve can cause stalling for the same reason too,if it opens when it shouldn't,or gets stuck open slightly sometimes...--be best to make sure its not that before blaming the carb...you might get lucky,and find the carb isn't the problem at all...take it off and fab up a "block off plate" and try it..I also have seen distributor advance weights get rusted and stick in the advanced position,that can cause stalling and poor performance too...