I was driving the datto today and she started idling at 1500rpm, i thought nothing of it till it climbed to 2000rpm, i gave it a rev to make sure the butterfly in the throttle body was returned fully and it picked up to 3500rpm! I disconnected the pipe from the throttle body to intercooler and put my hand over the throttle body fully, revs only dropped 500rpm ish, then i went full throttle and nothing changed. I cant hear/see any airleaks so my question is, is it only air leaks that can do this, what should i look for? Hopefully my head hasnt cracked an inlet port sucking in air as i cant find any damn leaks!

yeh could be air leaks.

Buy some carby cleaner(airosol) and spray it around the inlet gaskets etc. The rpm should change if there is a leak because it is burning the carby cleaner though the leak.

What kind of setup is it? I read L20B turbo in you sig. Id it EFI or suckthough?

thats a good idea beattie, ill try with some crc or similar, Yea its a custom injection system, im confused to say the least, would have thought id hear an air leak, hopefully just a blown gasket, may need to machine both manifolds flat if its blown

What gasket did you use after you killed the eazifit head gasket? Does it run with the aircleaner completely covered, if so its still sucking air to run.

Edit, sorry you did this, what manifold gasket did you use?

well if its idleing with your hand covering the throt.bod then its an air leak, take the plenum (or whatever you are using, intake manifold etc) off and change all gaskets (use a bit of aviation form-a-gasket on them), retighten all nuts/bolts and start the engine again. if it idles up past normal, kick it....

yea just another cheap ass sprint manifold gasket brand, yea might silicone it a little too, was hoping it might be something else. I can get it to idle at 1000rpm by backing out timing but then it wont rev damn it, yes i want to kick it, its giving me the ####s at the moment, gotta have faith and stick with it but

well i found my problem, cracked manifold, what could cause this???

Sorry to hijack your thread but what is that throttle body off it has less polution crap on it than mine

too much heat ..and cooling it too fast. After welding you should get it heat treated to get all the heat stress out.

Sometimes using the wrong filler rod will contribute to that too.

Thats sucks man, that would of been one massive air leak.

Could it be too much heat when welding caused the metal next to the weld to go brittle?

Edit, beat me to it dattodude.