Ok so new engine is installed and running great, however, I get high idle (around 1500) with the AC on.
I tap the pedal and it will bring it down to normal every time.
700RPM w/ AC on and 500RPM off.

2001 XJ w/ 98 ZJ block and head

Already checked vacuum, IAC and TB was cleaned well before putting all back together.

Otherwise, engine runs great

Thoughts?

 

How well did the 98 head match to the 2001 intake and exhaust manifolds?

 

It didnt
Actually wouldn't know by personal experience how far off the exhaust would be, but research pretty much revealed this before I even started the project, so I never even bothered to try it.
Used a header (SpeedDaddy) for the older head, then paid a shop to tie it up with the rest of the exhaust.

Intake was perfect fit to the head, but did take some beating at the header (pipe 1 and 6) to clear.

Cool notes about the 98 ZJ block; oil press sensor and oil filter location same as the newer WJ/TJ blocks... No adapters needed

 

Ok, so it did it this morning without the AC on.
Was about 1200RPM. Basically the idle difference with and without AC.
Maybe vacuum leak... but it is random.
Always comes down as soon as I tap the gas.
Very strange...

 

anyone?

 

bump