So I had a plenum spacer on my Z and since then my idle on really hot days was jumping up and down like 500rpms. Especally after being heavy on the pedal. Yesterday I took off my spacer thinking it would solve the problem and a wierd thing happened. Well, the car became much faster. Makes no sense. Also the idle is a little funky still and moves up and down only 200 rpms or so. Not as bad. I did not think much of it. Well today after stepping on the pedal, I got to a light, and the rpms just dropped all the way till the car shut off. What can this be?

 

i had problems with my car stalling after an upbrupt stop, or after pushing in the clutch and brake quickly. (to stop real fast) Sometimes the car would just stall on me. I had the altenator tested to make sure it wasnt failing, next i tested for vacuum leaks on my intake. After all that brought no solution, i changed my air filter that was passed due and i havent had any problems since. How dirty is your air filter?

My friend said he used to have the same problem in his '94 240sx

 

I have a new air filter that has been in my car for less then 6 months. So it could not be that

 

i'm not sure than partner. It must have just been Coincidence that it stopped doing it to me. Now that were talking, ill probably go for a ride now and stall out

Please update me if you pin-point what the problem is. Before it stopped, i thought it might be a fuel problem, like a bad line, or a fudged up gas tank stopping fuel on an abrupt stop. I dunno, i tried to block it out because it stopped happening.

 

I would check the air filter and see how dirty it is anyways.

Also - sounds like a vacuum leak - somewhere

 

same thing is happening to me after my AAM intake and spacer install... the only time my rpms jump, and the car SOMETIMES dies is when i turn my heat on and i am idling (Which sucks, but hey its summer...) or when my fan kicks on.. (sound like the same situation as you) i am going to go back and take a look at all my bolts for my pleneum. I put the intake and spacer on at the same time, so i dont know what is causing the problem... What vacuum lines should i check? The ones going into the top of the pleneum.. would make sense since we had to lift it up to get the pleneum in there... maybe it got pulled off a little.. anyone with pictures of where to look.

I also checked my top 6 bolts on the pleneum and there appears/feels and sounds like there are no leaks.

Dave

 

Check them all, really. They connect to multiple areas and one end could have come loose.

Also, your MAF sensor could have come loose when you took everything apart. Make sure it's good as well.

Another item to check/task to do. Remove the negative battery terminal for 8-10 minutes, put it back on, turn ignition key on, not starting though, and depress the brake pedal for 30-45 seconds. Then turn ignition off and restart.

This is the correct ECU reset battery method. Perhaps it's sensing something as well, that has been cleared up.

Rick

 

rick thanks for the ideas... i will try to battery check when i get home (as i have been meaning to do this for a week or so now..) ill let you know how it goes.

Thanks again.

Dave

 

Ok. So I tried cleaning the throttle Body with a spray.
I also cleaned my MAF with a spray.
Checked my AAM intake and it seems to be clean.
I tried re-setting the ecu.

Still the car shuts off on me. Especally on warm days. Anyone else have any ideas? One of my friends told me to change my lower collector, because it could have been stripped when AAM Installed my spacer.

 

you have a leak. the your intake pipe on the plenum side.

 

Update: So today I took the car to AAM to get it looked at yet again!!! 3'rd time there since I bought a spacer and intake from them.

They ended up saying that because of my AAM intake I need to buy a heat shield and it will fix the problem. (Reason being: that when the fan turns on, it sends hot air to the intake which makes the MAF sensor go crazy, which makes the rpm's jump up and down)

They installed my spacer again (since I took it off cause I thought it was the problem) and then also they installed the heat shield.

Well thoughts so far, I don't think its going to fix the problem but we will see! I will update this thread in a week or so.

 

No Heat Shield = Weird Engine Idle?

Next week's update = AAM: "After diagnosing your car, we figured out the real issue... you don't have twin turbos therefore your idle is irratic. But before you purchase those... In order to do it right the first time, one must also purchase a built motor (to be safe) and have it installed by us... oh yeah, make sure to also sign the waiver."

 

i have a funky idle with cold air intake. No hot air? I also had a funky idle with the short ram conversion. I think it's an engine flaw nobody can correct without turning up the idle slightly. (reflash)

 

I had re-flashed the car a while back. Anyways so far so good with my car. No funky idle yet.