emission hosing help 1983 305 5.0L

[Electric Medic]

Friends:

I have a 1983 Chevy Pickup with a 305 5.0L engine. Almost all of my Emission Hosing were cracked, all but the big ones that run down to the big canister and up to the PVC and over to the carb. However, all of the little hoses were cracked. I decided to remove all of them, from the two temperature vacuum switches that mount to the intake, right up front of the engine. I removed them from the carb and plugged all vacuum connections on carb. I straight ran a hose from the front of the carb to my dist. Advance. OK, now for my problem: The engine cranks fine and runs good with no skips now, however, when I turn off the engine and it is warm or HOT and the choke is wide open, the engine will not start. It just cranks and cranks. If I let the engine cool until the choke closes the throttle plates, it cranks up fine, then will run good forever until I turn it off. Then it won't crank again until the engine cools off. I was hoping I could take off those emission hoses without causing this. Is there maybe one line that has something to do with a vacuum to the choke or anything? Thanks.

[CRRoy71]

I am assuming you have the electric choke, if it's the stock carb.
Is the electrical wire still hooked up to the choke. Should be one wire on the passenger side of the carb.

Not sure if this is the problem or not, but that's the only thing I could think of.

[Electric Medic]

Yeah, it is electric choke, and it has a green wire running to the choke and it also has the 12v olts there.

Thanks

[CRRoy71]

I am no expert here, but it seems to me that when you shut your engine off hot, maybe your fuel is vaporizing. Then as it cools off, the fuel condenses back to a liquid and starts fine? Have you tried to manually choke it while someone tries to start it hot?

I don't know of any vacum lines going to an electric choke.

I am just guessing here, and trying to keep your thread towards the top so that someone else can give you some expert advise.

That's the best I can do.

[Electric Medic]

Thanks Chris and all. Yes, I still need help! Yeah, that is what is strange. It starts fine if I choke it manually while someone else cranks it. Even while HOT. I totally went thru the choke operation today, I found that the electric choke voltage supply line only has about 2.8 volts when hooked to choke winding, however if I remove the choke wire from the choke winding, it reads the proper 12v. I then ran another switched 12v to the choke and it doesn't load down that way. The choke appears to operate normally, it closes the throttle plates slowly after switched 12v is removed, then opens the plates when it is energized. Like you said, I am not even sure if I have a choke problem. I don't understand the workings of a choke fully, or how a engine starts when hot without the choke closing the throttle plates, but how you have to close them when the engine is cold. That is part of my problem. I removed those emission hoses because half of them were dry rotted and the engine was skipping, runs much better, but..now I have this starting problem when hot or even if I just drive it far enough for the ckoke to fully open. It will not start until the choke closes again, and that takes awhile. I only removed the hoses that were connected to those two temp. vac. switches in front of the engine, there are about 4 hoses to each switch. I didn't plug those two temp vac switches because I didn't feel any vac. there. I did plug the manifold vac port and the carb ones. The engine runs fine once you get it started. I know it has to be a problem with removing these hoses because I didn't have a starting problem before I removed them. I just thought someone has maybe removed them before and might have experienced this problem.

Perry

[Electric Medic]

I found this thread in archives and I didn't recalibrate my carburetor is maybe that is why it will not start when hot. I want to get some sort of eldebrok intake and carb and replace this stock stuff anyway soon, but,,I still have to drive until then. Maybe this emission removal did cause me some carb problems. Still needing help, stranded in Augusta, Georgia.
Perry

jimfulco
Senior Member

Registered: May 2003
Location: Shreveport LA
Posts: 658

You will need to recalibrate your carburetor if you remove the EGR. Removal without recalibration will cause pinging (detonation) under part-throttle acceleration. When you remove the exhaust gas from the intake charge, its volume is replaced by air, resulting in a lean mixture which will detonate. The EGR is not active at full throttle, so it shouldn't make a difference in power.