Just blows air when trigger is pulled.

The problem stated could be in one of two places.
1st the hammer mechanism, symptom when trying to loosen or tighten a nut the tool locks up. Disassemble and and check components for wear or broken parts..
2nd under a no load condition, depressing the trigger and only air blows through the exhaust could be a combination of hammer and motor. Also must inspect the anvil bushing (item #19) located in the hammer case, they have a tendency to slide out of place and binding the mechanism as a whole, then check air motor for scarred a
endplate (item # 12) cylinder (item# 9, damaged vanes (item# 11)
Follow this link to the parts list. http://manualarchive.ingersollrandproducts.com/ir_pdfs/Tools/Vehicle%20Service%20Tools/Air%20Impact%20Tools/45534070_ed3.pdf

The I.R. 2135Ti or TiMAX has some known issues with the trigger o-ring (item# 22A) swelling, the throttle valve (item# 28D) bending or breaking, and the throttle valve seal (item# 28E) wearing out or deteriorating. Procedure wise you should not be able to remove the trigger without first removing the inlet bushing assembly (item# 26) the reason is that the reverse valve (item# 24) keeps the throttle valve from tipping forward and releasing the trigger, there is a slot for the stem of the throttle valve to slide into.
Follow this link to the parts list:
http://manualarchive.ingersollrandproducts.com/ir_pdfs/Tools/Vehicle%20Service%20Tools/Air%20Impact%20Tools/45534070_ed3.pdf
When reassembling the tool first install the inlet bushing assembly and then install the trigger, make sure to lube the o-ring before inserting.

If debris enter the gun, over time the vanes will not move into proper positon and react to air-flow. Vanes can become stuck if stored for long period of time. Pour small amount of diesel fuel into the gun and activate the trigger. The fuel should come out clean, if however black gunk comes out, keep adding fuel until gun is clean. Eventually all the the debris will be washed out and restore function. Good luck

Since the engine is running it needs to have an exhaust port, If it is in fine working order I would assume that it is simply the exhaust from the chainsaw. even with the trigger not pulled you are still idling causing exhaust build up. I would need more information to be able to delve deeper.

Yes, if you take it apart you'll find that the trigger isn't allowing air to pass through to the veins of the impact wrench. It's a relatively simple mechanism, where maybe something is broken inside.

If it were blowing air but the veins were stuck, I would say, lubricate it. But, if no air goes through it at all, then the trigger housing houses the problem part.

Have you tried to disassemble the air wrench?

fill it wit oil hold in triger and flick between forard and reverse should free up the vains inside

first im sure you have tried this but use a lubricant on the trigger if that doesnt work try unscrewing the case and inspecting the trigger inside for broken or stuck parts you mayneed to buy a new trigger switch

Make sure that you have at least 50 psig of air pressure before you attempt to troubleshoot your impact. 70 is better, 90 is perfect. Impact wrenches are powered by internal sliding vanes, which can sometimes stick. There are a couple of ways to get it going again. Try 1 before going to 2, etc,:
1. Spray W-D 40 or a similar oil into the impact, while you are holding the trigger down. Give it a good shot. Connect the hose and pull the trigger. Tap the sides of the gun with a plastic hammer to help free up the vanes. Repeat. Normally, this is enough to get you back running.
2. Place it in a bucket and cover the gun with W-D 40. Work the anvil end and trigger to work the oil deep into the gun. Ley it soak 1 hour, and repeat the process, working the oil in, and the air out. Remove it from the oil, and drain the oil back into the bucket by holding the trigger down. Hook up the air, and blow it out.
3. Remove the cover on the head that covers the vanes. Make sure that the vanes will slide freely, and that all gaskets and "O" rings are in good condition. If you note any dry areas in the inner parts of the impact, lubricate with W-D 40, and reassemble.
4. I'm all out of ideas.. If that didn't fix it, I'd go get a new one.
Best of luck, --W/D--

if air sound comes out when you press trigger your pressure regulator pin is stuck-oil gun and attach hose repeate until pin frees or remove pin and clean with brake kleaN oil and replace

I have ran into this many times, even though you keep it oiled dirt can and will get inside. what you need to do is unscrew the 4 alen head bolts and pull the nose off. You will see a shaft that looks kind of like a crankshaft with 5 or 6 flat carbon fiber plates sitting loosely in groves around the shaft. pull those out and clean them with solvent and check them for damage or wear. clean the inside of the gun with solvent or brake cleaner, reassemble and it should work fine. If the plates need replaced then you should be able to order them from a tool supplier,and they are not that much.