ZE rebuild complete. Idle question- The symptom is. halp plz

[DiaMagus]

It was running fine until I wanged on it hard to 6k than it started to go from 1.5k rpm to 1k rpm back up to 1.5k rpm than down to 1k exactly on time. Its consistent- Sounds like vaccum to me dont know why it started after I revved it up. But when you shut it off and turn it back on its fine for 20 seconds than it starts doing the 500rpm up 500 rpm down and doesnt stop unless you shut it off. Im guessing a sensor or fuel pressure regulater. I dunno help me I wanna take this thing on the road. BTW It sounded sick when I wanged on it lol thanx

[JWMX3]

sounds typical for a kl. if everything is hooked up like it should be then a good tb and iac cleaning with carb cleaner might help you.

also, did your rebuild include new piston rings ? if so, its a very bad idea to "wang" on it right away.

there is break -in time on a rebuilt engine and a specific procedure to follow in order to seat the new rings properly... did you do that ?

[DiaMagus]

2k rpms for 10 min and 2.5k rpms for 2 min for break in :p WITH break in oil and break in cam lube/oil Gibbons fluids

[DiaMagus]

Not only the rings, dont forget about the bearings

[JWMX3]

you ran your motor at 2000 rpm with no load for 10 minutes ? ?

To seat piston rings in a rebuild you have to drive the car... usually 3rd or 4th gear. accelerate to 60, then leave it in gear and take your foot off the gas, dont touch the brakes and let it slow to 30 by itself. accelerate back to 60 and continue that process 12-15 times to seat the rings.

also change your oil after first startup, after 500 kms, after 2500 kms.. and dont abuse it until breakin mileage it passed. also Use dino oil for break in, not synthetic.

[DiaMagus]

I used break in oil started it a few times like 5 that sounds excessive as hell with changing oil three times I used Joe Briggs from my machinest? I should drain it now!? Why didn't my instructor tell me this? Wow ah

[JWMX3]

changing the oil like i mentioned is more a matter of opinion. But using the proper procedure to seat the new rings is critical if you want your engine to last. Joy revving a fresh rebuild to 6k+ just for fun before the tires have even hit the road is not smart.

how did the tps adjustment go ?

[DiaMagus]

Haven't set it yet ill be working on it in a couple hours

[Steeb]

Do u have a the check valve in your brake booster vacuum hose?

[Bolverk]

My RPMs will jump up and down like that while idling when its cold. I usually just turn on the rear defroster and it settles down.