I6 Cold Start Issue

[Winmon]

Having cold start issues with my 250ci I6 w/a manual choke. Once it is warm, it has no issue starting, starts right up. Funny thing is I can pour a cap full of fuel directly into the carb and it will start right up cold. I then checked to see if the throttle was feeding fuel and it was. It has a clear fuel filter right before it enters the carb so I know the carb is getting fuel. I then assumed the carb just needed to be gone through so I rebuilt it last weekend. Issue still persists. Any ideas what else to check?

[Nanook]

I would check the float level...

[Winmon]

Originally Posted by Nanook

I would check the float level...

Float level was way off when I disassembled the carb to rebuild it, thought to myself I just found the cause. Adjusted as per the rebuild sheet specs and did not seem to change anything.

[jtrichard]

When you say "throttle was feeding fuel and it was" are you talking about the accelerator pump/nozzles spraying when you "pump" the throttle? First pace to look is accelerator pump and choke when it dont like to start cold... " I can pour a cap full of fuel directly into the carb and it will start right up cold" also says accelerator pump is NOT working correctly

[TJ's Chevy]

X2 with checking accelerator pump. I have to wonder though....What's the initial timing set at?

[awbrown]

Explain your cold start issue , stalling ?? blubbering and belching clouds of black smoke ? what is it doing ??
If it is a manual choke ,normally you control all it does ... once it is pulled crank til it starts and at that moment you much push it in till it runns smooth ,also with the choke pulled , it should raise the idle ,and the idle should come down as you push the rod in .. Does it work as such ??

[Winmon]

Thanks guys!!!

When you say "throttle was feeding fuel and it was" are you talking about the accelerator pump/nozzles spraying when you "pump" the throttle? First pace to look is accelerator pump and choke when it dont like to start cold... " I can pour a cap full of fuel directly into the carb and it will start right up cold" also says accelerator pump is NOT working correctly

X2 with checking accelerator pump. I have to wonder though...

Accelerator pump was my first thought and main reason for rebuild, it was replaced when the carb was rebuilt.

What's the initial timing set at?

Have not checked the timing yet, will have to do that

Explain your cold start issue , stalling ?? blubbering and belching clouds of black smoke ? what is it doing ??
If it is a manual choke ,normally you control all it does ... once it is pulled crank til it starts and at that moment you much push it in till it runns smooth ,also with the choke pulled , it should raise the idle ,and the idle should come down as you push the rod in .. Does it work as such ??

It will not start at all for the first several times trying (with choke on, even tried it at various openings), you really have to keep at pumping the throttle a bunch, then it will finally fire. The choke seems to be working correctly, brings the idle up and if turned off too soon, when still cold, it will want to stall. Once it does fire and warm up a bit, it fires super easy with no effort every time.

It does seem to have a "surge" though at speed now also.

[jtrichard]

Just because you replaced the Accelerator pump does NOT mean it is working .... is it squirting a good stream into the carb?

[TJ's Chevy]

Originally Posted by Winmon

Thanks guys!!!






Accelerator pump was my first thought and main reason for rebuild, it was replaced when the carb was rebuilt.



Have not checked the timing yet, will have to do that



It will not start at all for the first several times trying (with choke on, even tried it at various openings), you really have to keep at pumping the throttle a bunch, then it will finally fire. The choke seems to be working correctly, brings the idle up and if turned off too soon, when still cold, it will want to stall. Once it does fire and warm up a bit, it fires super easy with no effort every time.

It does seem to have a "surge" though at speed now also.

Has it backfired at all? Like when pumping and pumping? When you punch the throttle has it backfired? Normally that would show a sign of it running to lean. If the accelerator pump wasn't working the engine will have major hesitation when given throttle. Had that same issue with one of my 6 cylinders.