Hi guys have some issues with my EB XR8.
I replaced the head gaskets and now have it all back together my issue is it still hi revs on start up and cant work out why have had this issue for a few years now and its been running to lean.
Have replaced the intake manifold with a really good 1 as mine was corroded out,
I used permatex rtv ultimate gasket maker for the intake ends but still no different, has just had the injectors done so shouldn't be there I have even bypassed the brake booster and the black lines to the dash and still the same.
I'm going nuts on what it could be
any help would be great

Checked MAF?
Then there is the Air temp sensor in the lower intake plenum. The coolant temp sensor? Perhaps the ICV on the side of the intake stuck or slow (dirty) - it regulates the exta flow of air past the throttle flap.

Basically can be a few things, but if you have done the heads and intake gaskets, you can rule them out leaking.

ok so have done a few tests now and still the same.
1. Bypassed the valve thingy on the strut tower drivers side no luck
2. replaced the idle control sensor no luck.
3. cleaned and checked the EGR no luck
4. checked the vacuum hoses and even bypassed the ones going into the cabin no luck

Going to do a check on my MAF sensor and MAP sensor
Replaced air temp sensor and coolant temp sensor with new 1s no luck
dizzy has new electrical box and new coil.
I had issues a while back when it wouldn't start and there was a S.P.O.U.T thing in the ECU that I had bypassed and its been high reving since.
Once the idle drops to normal when you put in reverse or drive the high revs begin again until ya put into neutral then back to normal revs

if its idling fast all the time check tps voltage, if its over .9v at idle turn the idle screw down a little, someone may have adjusted it in the past?
for the lean running have you replaced the 02 sensors at all?

Yea i have replaced o2 sensors about a month ago
Revs at 2000rpm for about 40seconds then returns to under 1000rpm does this hot and cold.
I reset the tps its at .97v not running
This problem has been like this since 2009 when the intake was leaking water so removed it repaired and installed then this is whats been happening.
I have noticed that if i clean the maf sensor it a little better for about a week or so
Gonna test that tonight

what about the idle speed controller?
try cleaning that as they do get lazy when they get dirty or corroded inside

Have done that to and i thought i fixed but i forgot to plug it in
When i remove the ics it dies
Timming is at 30 degrees aswell
As soon as i put it in reverse it hi revs again until i neutral it
Mmm its a brain teaser

Just wondering whether the TCM is telling the ECU to bump idle usually when put in gear. If that signal is given (cant remember whether that's actually the case on EB) and something is cactus there, maybe thats why you experience the idle issues.
You certainly have an interesting one there mate!

Anyone got something that could help 1966 Xr falcon out?