GavinJuice

I finished replacing all 3 intake manifold gaskets and as many vacuum lines in the process of getting my port actuators to work. They work now which was my goal. When i start my car now and let it idle i get about a 1500-1200rpm idle. Now i know most of you are going to say vacuum leak but i can't seem to pinpoint it anywhere. I doused my engine with starting fluid with no difference, i used propane and probed all over to find something with no avail also.

My cruise control cable seems to be tugging on the throttle a bit also, when i tug back on it the idle will drop to like 600 and i get a loping effect at idle. I can't seem to bump it up with the air adjust, just bring it down. I get kind of a vroom.....vrooom.....vroom idle. I also get the same thing at a higher idle but it's not as noticible inside, but looking at the engine you can see it's not smooth. I changed my plugs which i totally forgot them being fouled out, it seemed to help a bit. My throttle was sticking on the fast idle cam a couple times at idle.

I was thinking seen as how i lost coolant that maybe i am low causing the wax pellet to not warm up,cool down properly, but I did top it off though.

Ok so here's the recap, i'm looking for help on the loping idle, possibly electrically related as in wires cap rotor? I'm thinking all these little problem all relate to my problem of the idle.

nevarmore

The loping noise might be the mixture. You need to adjust both the idle speed and the idle mixture. The loping noise is beacuse its a tad lean.

WankelingBeer

ChasRX

Please clarify...Clockwise to lean; counterclockwise to richen?

Mr BiG G

couldn't it be air in the cooling system? wat exactly is a loping idle?

ChasRX

vroom...vroom...vroom. Like the idel is 'chanting' I suppose; not smooth and consistent.

nevarmore

Yep. It'll sound different. Lean makes it 'hunt'. Read this: http://www.sterlingmetalworks.com/idle_circuit.html

Good directions coming from the best in the buisness. The only thing he couldn't really help me with was figuring out how to thread my screwdriver around all the crap in the bay and on the carb to get to the idle speed screw.

slashdawg00110

Have you looked at the SE idle troubleshooting threads in the FAQ? I'm assuming you still have fuel injection on this one.

nevarmore

D'oh! If its fuel injected disregard everything I've said. I was giving advice for carburetion. It still sounds like a lean conditon but I'm not sure how to go about dealing with that on a FI motor.

GavinJuice

I did think about the mixture, but to set it according to the FSM you get a constant 800 idle and turn it (i can't remember which way) till it drops to 780. But i don't have a constant idle to begin with which is my problem. It made me think of that when i noticed my car really stinks now. If i pull it into the garage to tune the idle, i'll walk out and my clothes just reak. That made me think Rich, not lean. And yes it does seem to be hunting, the effect of having my tps out of adjustment gives me pretty much the same effect. BUT, it is properly adjusted.

Does anyone have any ideas as to properly adjust the mixture without having a steady 800 idle? And also, can anyone follow up on Mr BiG G's response on air in the cooling system? I'm pretty sure there's not, i had no fluxuations in temp when running.

djjazzynads

I just installed a rebuilt motor in my 85 GSL-SE and I have the same exact problem. I am attempting to follow the instructions in the FAQ, but so far it has been to no avail.

Kentetsu

Not sure how similar these FI systems are to Nissan, but I'll take a shot here...

I had an '83 Z car, washed the motor, and ended up with an idle that went from low up to something like 3k, over and over again like it was cycling. Turned out to be a wet connection at the throttle position sensor. My dad had the same thing with a VW rabbit, so maybe this isn't so rare. Might be worth a shot. Good luck.