So I just rebuilt the engine and installed bigger cams and I know I need a tune. But I’m breaking in the engine before I take it to get a dyno tune. Meanwhile the thing doesn’t want to idle. Is there anything I can do to help it idle better until I get it tuned?
Idle issue is common w/new cams and no tune. I had to do the same thing - break in time to seat the new clutch and to make sure cooling is working, no leaks, etc. You can crack the nut loose on the idle screw loose and turn it in a bit to try and get an idle, and will need to milk the idle when you come up to stops when the engine is warm. I broke mine in 350-400 miles before going to dyno - it may be lean in spots or rich in spots, so just don’t beat the daylights out of it, and know that it will probably run tougher and sputter during tip-in (partial throttle) and may load up when idling. It may pop at lower rpm under load, so keep the motor at moderate rpm’s when cruising, so it isn’t lugging. Not fun in any traffic so best in rural areas with some stops & goes. Much easier with a clutch car.
Sometimes you have to run the motor in before the dyno, but it won’t be running its best. In my case I cannot strap it on a dyno with a brand new clutch kit & flywheel - they need some break-in. They are correct, though, that fuel and timing will be off quite a bit with cams. If you change up your injectors, a base tune is definitely needed so you don’t wash out cylinders.
When you go in for tuning, change oil and let them know you adjusted the idle (mine was all the way in w/stage 2 cams and still only idled well after cold start-up .. once warm idled like garbage). The tuner can adjust everything for drivability and tip-in.
