HELP PLEASE: Engine Idle Problem
 

Hi Everyone,

I am experiencing an engine idle problem. I just bought this car

HERE'S MY PROBLEM.

My engine idles fine in park, HOWEVER, as soon as I turn on the AC and I'm in park position, the engine begins to idle up and down between 500-900 RPMs. It has even stalled once. I took a look under the hood and this is what I discovered. (See pics below) Picture 1 & 2 shows kink in hose. Picture 3 is of a proper install with the horse shoe shaped coupler.

There is a kink in the hose originating from the Stillen left air intake going to the crankshaft. I'm not a car mechanic expert at all, but this does not look good. I am going to have my mechanic fix the problem ASAP. The proper install is shown on the 3rd picture where the hose is connecting to a horse shoe shaped coupler. I received this picture directly from Stillen after speaking with their tech, although it is a picture of a G37, its the same engine.

Could this be the reason why my engine idle is acting erratically while parked and the AC is on? Your opinions are highly appreciated. Also, what are the negative impacts this kink in the hose could present? I have parked the car until I have it fixed.

Unkink it and go for a drive.

I plan to but you didn't answer the question posted. Thanks.

What I meant was, unkink it and see if it has anything to do with the AC first hand.
It's a hose. Just make it straight.

I'm going to have my mechanic fix it properly with the correct fittings and with the horse shaped coupler. There is basically ZERO air flow going through that hose! ARGH! But I believe that could be the problem. THanks and I'll post the results after the fix.

Does the horseshoe shape coupler come with these intakes??
Like did Stillen mention it because if not, It would be good to know for all the Z ppl with these intakes.

I see the problem. You're completely missing the coupler. Whoever did this install doesn't know how to follow simple directions. :shakes head:

Below are some pics I just took from my car. If you get that part installed properly and it still gives you problems, the next most likely suspect would be the UD pulley. Keep an eye on your voltage gauge to see if it fluctuates wildly with turning on the AC.

^ What he said. That "horseshoe coupler" comes from the stock car, and is supposed to still be used when you install the Gen 3 intake. Looks like they tossed it and tried to hook up the hose directly without it, resulting in the kink. I can't imagine it would affect idle that badly, but who knows, things are complicated sometimes :)

SEMTEX,

I still have the original intakes, and YES, you're right. The guy did not attach the horse shoe shaped coupler as it is still attached to the original intakes. Also, as you mentioned, I did notice a slight fluctuation with the voltage gauge. Not much but it is noticeable. I see that it fluctuates a smidgen below 12 but it constantly remains just above 14 for the most part. I will play around with the AC and let you know.
Is the UD pulley the same as the crankshaft pulley? I have the crankshaft pulley from Stillen installed and I fear it may not be installed properly if the same guy did the install on the intakes.

MY FINAL QUESTION. Could the kink in the hose be the cause for the erratic engine idle?

Stillen makes two crankshaft pulleys. A lightweight one that is stock diameter, and an underdrive one that is smaller (and thus underdrives that accessories). And yes, that kink in the hose could be the cause of the idle issues. You know that you can download the installation instructions from the Stillen website, right? They're pdf files. Might come in handy.

I have the UD pulley Stillen part # 400370. Yes, I know about the PDF files. Already printed them out and ready to give to my mechanic. He's so busy, I have to book at least 3-5 days in advance. He's scheduled to fix next Thursday. I'll give an update then. Thanks for all the helpful replies!

It would be super easy to fix the horseshoe thing yourself if you want to. It goes together in a pretty obvious way, as you can see in the pics you've posted. If I were you I'd do that yourself ASAP and see if it fixes the idling issues you're experiencing.

Did you order the replacement Gates belt that goes with the UD pulley? It's shorter than the stock belt, you might want to double-check it. If they re-used the stock belt it would slip, which might cause some of your idle issue as well.

As far as voltages go with the UD pulley: With the engine warmed up and idling in neutral, it should be at least on the 14 mark, if not higher. Mine will dip pretty low (not quite to 12) under certain conditions briefly, but it never stays low. "Certain conditions" being things that suck more amperage, like the end of the power window auto-up and auto-down movements.

Thanks WSTAR! I have the appropriate Gates belt from Stillen. The previous owner gave me the original pulley and original belt. I guess I could do this fix myself. I'm going to my local parts store for the fittings to tighten the hoses to the coupler. Thanks everyone! I'll post an update after the fix.

^ see, I beleive in you to fix it urself...... U just have to beleive also.