motor surges

Well ever since i put my ZC in the motor surges up and down at idle it goes from 600 to 2000 rpm up and down up and down up and down well ya get the point not real sure what it could be i have ben figling with it four 2 days now any help tnanks

lol, same problem here! :D

Damn, that shit is soooo anoying. I have not had time to really look it over. I can think of a few things to check though.

-Make sure all vacuum lines are hooked up correctly, and no leaks.
-Timing set properly..
-Sticky throttle cable.
-User error. :D

Yeh, my first b16 did that when we first did the swap. We had the vacuum lines mixed up. It did it once again when we changed the Intake manifold gasket...there was a large vacuum leak. If you spray like carb choke cleaner or brake clean on the intake/vacuum components while the engine is surging like that- and if the idle is normal for a second or two when you spray a certain area then that is where your leak is. You most likely just don't have the vacuum lines hooked up correctly, tho. Do a search for a vacuum diagram. :cool:

well unless i am missinf some lines i am not sure what to look for this sucks and it is running real rich also.

you are running really rich? Check your FPR (fuel pressure regulator) vacuum line connection.

got vacum to the regulator and hoses are conected stillno go :(

I sort of have this same problem. I haven't done any swap, still the stock D15, but everyonce in awhile my idle will surge much like that. Then after I take off it will go back to normal next time I stop.

how can you tell if your really running rich or lean? I think im running a bit rich but dont really know what to look for to make sure.

on my d16z6 engine swap, the first time i start the car after it has been sitting a couple hours, it will fire up and then cough and sputter & die a couple seconds later. Then i will start it up again and it will run smooth. Im not sure what the problem is.

My ecu is throwing O2 sensor, so i changed the O2 sensor and it is still throwing a code. Im guessing that maybe my injectors arent keeping up with my engines performance needs because im using HF injectors. I know it is running lean because the car knocks sometimes and pings, and the spark plugs indicate lean burn.

From what i have found on the net this a problem but nobody has an answer. ever thing checks out. does any body have a pic or can take a fpic of the vacum line routing on a ZC motor that does not act up i can not drive this car like this i can not stand a car that does not run right.


the car idled right for about 1 day and it is back to surging again its time to Sell IT if this is somthing that i am just going to have to live with.

wich valve is the idel air contorl valve and will the one off the stock si motor work. on the zc

Check the idle speed. Disconnect the EVAC (back side of the intake) then set the idle to ~750 RPM with the engine warmmed up and all accesories off. If it is set too high the EVAC tries to compensate then it almost stalls,the EVAC then opens up too far, idle shoots up too high then ....... over and over again. This fixed mine! Hope it works. This is assuming the vaccum lines are all where they are supposted to be and not leaking.