Rough Idle

I have a 87 Chevy S10 Blazer with a 2.8 liter engine. It was running fine until I changed a valve cover gasket that was leaking oil. After putting it back together it does the following:

Upon starting the truck, it idles really low and rough. After 5-10 seconds the idle picks way up and runs smoothly. Within about 1-2 seconds of the idle going up, the "Service Engine" light comes on and stays on until the truck is restarted. The idle stays high from this point on.

This is duplicated everytime I start the truck. It does seem to run fine when driving it, though it does seem to run a little rough.

I'm positive I have everything back and connected, though I did have to repair two crappy/broken hose connections (1 from the passenger side of the carb to the air filter and another larger one from the passenger side of the carb also). I'm not sure though what causes this light to come on, or what causes the idle to pick up.

Any help would be much appreciated.
Jon

You'll still have a broken hose somewhere or a kinked hose

Don't waste your time hunting for a hose. Let the ECM point you in the right direction. Retrieve the stored error codes and go from there. Why fight it?

That truck is OBD1 of course, Have you checked to see what the codes are registered in your computer. You don't have to have a scanner to check the codes. Locate your DTC connector and take a wire and plug it in the A terminal and the B terminal. Turn your key to the on position ( do not start it) watch your instrumnet panel for the service engine soon light. It will flash one long flash and then 2 short flashs. This means code 12, it will flash the code five time, then after that, count the flashes after that. if it flashed three times , then pauses for a second and then flashes 2 times, that means it has stored a code 32 in your computer, if it continues to flash, count the flashes because it may have more codes. If it goes back to the code 12, then there are not any more codes stored. I hope you can understand this and I hope it helps. Post back with results if you can.
Thanks
SC