88' D100 3.9L stalling out
 

Can someone help me track down a problem. My Truck starts on the first crank idles amazing but stalls out at soon has I put it in gear. just did plugs and wires because it was having idle problems but now runs fine. I was thinking it's a timing problem or the egr valve. 90k miles

90K is a bit early to need a timing chain. Since you have fuel injection, I'd clean the throttle plate. Get a can od spray fuel injection cleaner. Don't get carburetor cleaner unless it specifically says it's for fuel injection. Gummout used to say on the can to NOT use it for F.I.. It can damage the inside of the plenum and cause problems. Open the butterfly plate by hand and using a paper towel, spray around inside the throttle throat. Rub the paper towel in there. You'll see a bunch of gooky stuff (<----fancy technical term) on the towel. This is from the EGR and PCV valves. It builds up and causes air flow problems. Once you have it clean, reassemble the air cleaner and start the engine. It WILL be hard to start and run really rough. That's all the crud you washed off the throat and plate burning off. It will smooth out and run better in a couple of minutes. The reason you use a paper towel is if a piece gets loose, it will burn right up. Cloth may hold a valve open a bit and start a burnt valve down the road.

We are ordered a new egr valve and hoses. Turns out the line running of the exhaust manifold had dry rotted underneath and we didn't notice till it broke from us unhooking it