Engine stumbles below 3500rpm

[GunRunner]

This past monday I had a mechanic replace my intake manifold gasket. After picking up my car tuesday after work I noticed on the drive home that below 3500rpm that the engine seems to skip/stumble/choke somewhat while accelrating. This also causes the car to shake. after 3500rpm its drives like normal. This only occurs after the engine is warm and has been run for several minutes. So far I have replaced the spark plugs and spark plug wires. I need to get all these bugs out before the spring meet (2 weeks).

EDIT: I called the mechanic this afternoona nd told him what was going on. He told me to look for any loose hoses. I have looked from under the hood and under the car. I cannot find anything out of the ordinary. I won't be able to get my car back to the shop until monday afternoon due to a wedding i'm in this weekend. Good thing dad has a spare car

NOTE: In each video clip the throttle was held at a steady position.

Video Clip 1:

Video Clip 2:

Video Clip 3:

[The G-Man]

I would say check any and all things attached to the intake manifold, make sure coolant is getting to it. Maybe the IACV valve?

[GunRunner]

video clip 1 posted

[GunRunner]

video clip 2 posted

[GunRunner]

Last video clip posted. Any help will be appreciated.

[Fake Thug]

Your IMG might not sealed properly.Take some carb or throttle body cleaner and with car running at normal operating temperature spray around the intake mani gasket and all the vacuum lines going to the plenum and vacuum box.. If you notice any surge or drop in engine speed(rpms) that hose or the img is the culprit.

[GunRunner]

Your IMG might not sealed properly.Take some carb or throttle body cleaner and with car running at normal operating temperature spray around the intake mani gasket and all the vacuum lines going to the plenum and vacuum box.. If you notice any surge or drop in engine speed(rpms) that hose or the img is the culprit.

thanks man, great idea. I actually hadent thought of that.

[GunRunner]

Your IMG might not sealed properly.Take some carb or throttle body cleaner and with car running at normal operating temperature spray around the intake mani gasket and all the vacuum lines going to the plenum and vacuum box.. If you notice any surge or drop in engine speed(rpms) that hose or the img is the culprit.

oki did this jsut a few minutes ago. The engine did idle DOWN while i sprayed the IM where it bolts to the head. Guess it is not tight enough? any more ideas will be helpful. Also I still cannot find any loose vaccum lines/hoses.

[NAiL05]

Either bolts are not tight enough OR the gasket is shot in that area.

[Fake Thug]

oki did this jsut a few minutes ago. The engine did idle DOWN while i sprayed the IM where it bolts to the head. Guess it is not tight enough? any more ideas will be helpful. Also I still cannot find any loose vaccum lines/hoses.

Does he warranty his work?
Take it back to your mechanic and have him recheck his work.

[GunRunner]

Either bolts are not tight enough OR the gasket is shot in that area.

I checked the bolts jsut after making my last post. I turned about 4 of them 1/4 of a turn. Then took it downt he road much further than i have been for it to start messing up. Ran like normal. Probabily drove about 8 miles. Once back in my driveway idling in 1st gear jsut rolling i gave it gas and it started to stumble some but nothing like it was. So tomorrow after work I'll be coming home and checking the lower bolts of the IM.

Does he warranty his work?
Take it back to your mechanic and have him recheck his work.

He is a family friend, so no problem with him correcting a problem he made. I plan on stopping by tomorrow since I go right by there while working.

[GunRunner]

Update

Ok, Now I have tightened all of the IM bolts and the problem is still there. Car will be going back to the mechanic soon. I have to get this thing running right before I make the drive to the spring meet (May 26). I hate having to take it to a mechanic but I jsut dont have the time to mess with it right now.

[NAiL05]

Does it idle funny? YOu can try cleaning out your EGR that can cause some low RPM stumble.

[GunRunner]

well it does idle funny. and it only acts up after the car has been driven for a while or when it is hot outside like it has been lately.

Either way its going back to the mechanic this week (maybe tomorrow) because it was not doing this until after the im gasket was replaced.

[mtnickel]

I have a similar problem...mine was a result of high boost and overheating.

It only ildes high, and it has that hesitation and sounds like it misses sometimes.

When I cover the air intake completely it still idles, so must be a pretty bad leak.

I also have my Crankcase ventilation plugged off and checked all vac lines. Not running the best.