Cobra hesitating at 1500-2100 rpm?

[006]

Yes, EGR system is stock.
Serpentine has about 1500 miles on it, good shape, no fraying
AC compressor is still on vehicle and works normally.

The green and red vacuum hoses that plug into your EGR spaceship at the top of your engine along with everywhere else they are plugged into, the little hoses cannot be jammed all the way into the little rubber boots. If so, it causes them to bottom out at the 90 ° end in the rubber boots and stops the vacuum from initiating open the EGR.

The hoses have a small bulge where they meet the black rubber boots. Make sure the bulge is NOT inside the boot, but rather should be visible outside just at the entrance to the boot.

Also, your EGR vacuum solenoid could be bad, but it' rare.

http://m.ebay.com/itm/121635528263?_mwBanner=1

Your problem is EGR related for certain because all low rpm hesitation in that range is affected by the operation of the EGR.

This is the thread that led me to solving my issue:

http://www.svtperformance.com/forums/showthread.php?1085668-Egr-related-stumble-jerking-SOLVED

 

[isdnmatt]

The green and red vacuum hoses that plug into your EGR spaceship at the top of your engine along with everywhere else they are plugged into, the little hoses cannot be jammed all the way into the little rubber boots. If so, it causes them to bottom out at the 90 ° end in the rubber boots and stops the vacuum from initiating open the EGR.

The hoses have a small bulge where they meet the black rubber boots. Make sure the bulge is NOT inside the boot, but rather should be visible outside just at the entrance to the boot.

Also, your EGR vacuum solenoid could be bad, but it' rare.

http://m.ebay.com/itm/121635528263?_mwBanner=1

Your problem is EGR related for certain because all low rpm hesitation in that range is affected by the operation of the EGR.

This is the thread that led me to solving my issue:

http://www.svtperformance.com/forums/showthread.php?1085668-Egr-related-stumble-jerking-SOLVED

!!!!! You are the man!!! Exactly right. I plugged the vacuum tube on the egr valve and the problem IMMEDIATELY WENT AWAY! Now next step is to turn that off in the tune.

It has been miserable to drive the car around town. I almost avoided it. I have been driving the car for like 5 years this way. This has completely changed the way the car drives. Thank you. PM me your email and I'll send you something! Thanks! Thanks! Thanks!

 

[006]

!!!!! You are the man!!! Exactly right. I plugged the vacuum tube on the egr valve and the problem IMMEDIATELY WENT AWAY! Now next step is to turn that off in the tune.

It has been miserable to drive the car around town. I almost avoided it. I have been driving the car for like 5 years this way. This has completely changed the way the car drives. Thank you. PM me your email and I'll send you something! Thanks! Thanks! Thanks!

Lol, glad to help you solve it. I knew that once you eliminated the AC compressor & serpentine belt, only main culprit is the EGR.

No need to eliminate it, just make sure it's operating as it should.

Check all the hoses & boots to make sure there are no restrictions or it could be the vacuum solenoid.

 

[isdnmatt]

I've plugged it for now and disabled it in the tune. The vacuum lines seem to check out so I order a new solenoid. This will let me drive it until then. I immediately took it our for a 35 mile drive, just to be able to use 5th and 6th with ease again. What a huge difference, I can't believe it took me this long to figure out.

Thanks again and let me buy you a beer or something!

 

[isdnmatt]

Is there a specific range they should be in? I have a set of coils in the garage and I know one or two are bad. I'd rather not have to play the swap the COP game.

On another note, I would like to know the same thing. Seems like my original set was fine and I would like to double check them so I have spares.