Code 21 After long sitting & under plenum repairs. Help...

[My_Q45]

Hey,

I just got my Q put back together after 4 months of sitting in the garage. I was planning on working on it & took the manifold off. After that I lost the time & have been using my jeep since. Now that I have finally put it back together, I am getting a code 21. It was not doing this before. The work I just finished is as follows. Replaced the knock sensors, temp sensor & rotated 2 injectors that are going out with 2 newer ones.

I know the code is related to the ignition & about 18 months ago all the coil packs were replaced. I really feel it is just a forgotten wire but I don't see any missed! If anyone has an idea as to trouble shoot it or a common forgotten wire, please let me know.

Thanks...

[elwesso]

I get the exact same code..... my car runs perfect........

[My_Q45]

Very odd... I haven't even gotten to drive mine yet. Since I got my car it has felt sluggish & am pretty excited to see what it's got now. I just hope this will be a cheap or easy fix.

[elwesso]

Id just go back and double check all connections.......

Just go ahead and start it up, and see how it runs..... IF you have any symptoms, let me know....... Id be really interested to see what you can come up with, cuz I dont even have anything to go by, since it runs the same or better than the day I bought it!!

[My_Q45]

I already started her up. At first it wasn't a happy car, but about after 6 seconds it quited down with a bouncy idle. After another minute the engine seemed smooth. Turned her off & checked the codes. You know the rest. I'll take her out tomorrow for a test drive & post my results.

Have you had any ignition system work done?

[elwesso]

I replaced the plugs about 4 months, or 1000 miles ago (I dont drive very far)...... Ive checked codes thrice since I did it, and the most recent time is the only time Ive gotten the code.....

Only "symptom" i notice is that its a little hard to start... Instead of the normal 2 cranks, it takes like 4, only when cold..... When its warm, 2 cracnks........

It runs perfectly smooth and quite, idles right on at 650.......

A lot of people have mentioned something about a rough idle after a plenum job...... Maybe the ECU not used to the cleanliness?? Usually they take it out and its golden!

[AZhitman]

Wes - There's no 16" Q BBS rims.

[Q451990]

...with a bouncy idle. After another minute the engine seemed smooth.

That sure sounds like an injector to me. I think I'd run it for a while, clear the codes, and see if it comes back. I'd think sitting that long can allow some corrosion and mositure that needs to get cooked off.

Heath

[elwesso]

Any results!!!?

[My_Q45]

Sorry about the delay...

My keyboard decided to leave this world today. Hopefully it will be happier at the garbage dump!

Anyway...I started up my car today & it ran like crap! I heard a vacuum leak & found an unconnected metal line but can't find it's mate. I am confused since yesterday it idled well & no sound of a vacuum leak. I'm gonna start a new thread on that topic so it gets the proper attention.

So sorry but nothing new to report.