Wsup Acurazine,

I've spent the past two days installing the CTSC with the low boost pulley on my CLS6. 93 Octange Gas.

I am concerned however with the high idle at 1200-1500RPM. I believe it should be at around 700 RPM.

At first, I thought it was because I did not burp the air out of the radiator. My theory was that since the coolant was hot, the ECU commanded the car to idle higher to have the coolant flow more hence preventing damage from overheating.

After leaving the radiator cap open to let the air out for about 5-10 minutes with the car runnning, I checked the idle and it was fine.

This morning, upon start up... the idle RPM was 700. After driving 5-10 minutes, the idle RPM once again shoots to 1200-1500. When this happens and I shut off the ignition, the car shuts off "roughly" with a slightly violent shake.

I wonder what is the cause to this dillema.

I bought the SC kit used from another memeber on here. He was running it with gReddy emanage blue. I, however, decided to run the CT ESM since I have no funds for tuning.

Maybe when the previous SC owner had it tuned with the emanage, the shop adjusted the FPR? Could this cause my problem? How do you remedy this?

Could improper blower belt tension cause this as well?

Any perspectives are welcome and appreciated. Thanks guys.

 

Update:

The ESM voltage was at 2.915V.
Changed the ESM voltage to 2.924V, just below the recomended 2.93V
Should this help?

 

sounds like a big vacuum leak. check all hoses and piping. make sure all the hoses are properly connected to the throttle body and the upper intake manifold and all gaskets are present and not leaking.

 

^^what he said, or clean your IAC sensor

 

Thanks man. It seems as if you are the supercharger expert on this forum these days.

If there is a vacuum leak tho, wouldn't the RPMs fluctuate up and down? I don't have this problem.

I rechecked all the hoses, and they are all properly connected to the TB.

After adjusting the ESM voltage to 2.93 however, I haven't seen a high idle. I didn't know a .015 voltage difference could make that much of a difference.

I don't know if the idle problem is gone tho for good. I will post an update later tonight.

I hope that everything is in good working order. Fingers crossed. Don't wanna end up blowing my engine.

 

Do you mean the IACV? If so, the previous owner of my CLS had that replaced already so I'm sure it isn't dirty.

But thanks for the suggestion.

 

Take a look at it anyway. Im having the same IACV woes with my car after the manifold swap. Pull the intake tube off the throttle body and block off the lower (larger) port with you finger while the car is running. Does the idle drop?

 

I would take the IACV off anyway and check. Don’t just check it, run some brake cleaner through it or throttle body cleaner. If the Idle is not fluctuating then it probably is not a vacuum leak. Just because a part is relatively new doesn’t mean it couldn’t be dirty or not functioning correctly. Also make sure the operation of the Throttle body butterfly is smooth. I would get an old tooth brush and clean the bore of the throttle body and butterfly with the TB removed using the throttle body or brake cleaner. The two types of cleaners mentioned can be had at any auto parts store and are in an aerosol spray can.

 

My car idled high right after I installed the light weight flywheel, but after a day it went away

 

So I just got back from a test drive to try and identify anything abnormal.

1. When I first start off the car (cold), the idle is fine.

2. When I hit bumper to bumper traffic, engine temperature (hot and normal), the longer I sit still or if moving at low speeds, the RPMs gradually rise higher from 1200, to 1500, and even sometimes 1700.. But never over that (so far).

3. When at a stand still at a light, twice, the idle fluctuated up and down and was surging. Exactly like a vacuum leak. But why a vacuum leak all of a sudden? Then no vacuum leak...

4. When I'm cruising, everything seems fine. If I cruise long enough (40-60mph) the idle returns to normal. If I cruise long enough (25-30mph) the idle is not quite normal, but slightly higher perhaps at 1000 RPM.

One thing I realized is that the cap I'm using for the CT modified coolant overflow bottle is not the right one and will not close. It fits very loosely in fact. I have to get the right one. Do you guys think that this could be the source of the problem? I suggest this since the Cooling system IS a closed system afterall, and a loosely fitting overflow cap with a hose connected to the radiator can very well introduce air into the system, as well as a leak, and a pressure or vacuum problem.

I'll take pictures tmrw morning of all the vacuum line connections. I'm pretty sure everything is connected, but will recheck.

 

Ima check tmrw morning, but if the idle does drop.. what are you suggesting?

 

Actually, the idle fluctuates rarely and intermittently. If it was a vacuum leak, what would cause a vacuum leak to come and go as it pleases.. the IACV? How does the IACV operate and based on what input?

 

Also, I noticed that the Supercharger whine is quieter than I expected. I only hear the whine when I floor the car.

1st gear: The RPMS rise so rapidly that the sound from my Magnaflow mufflers, and the loud Vtec noise prevents me from hearing the whine.. sometimes it sounds as if the SC isn't even there.

2nd gear: When flooring it, I can hear the whine better than the whine in 1st gear. But when slowly climbing the RPMS, I can barely hear a whine.

3rd gear: When WOT, I can hear the whine, but again.. it is not as loud as I expected. Is it because I'm inside the car? When slowing climbing the RPMS, I do not hear a whine.

4th, 5th, 6th: Whine is almost unnoticeable

Is something wrong ? Or is it just my head messing with me here?
I thought the SC whined whenever you pressed the gas....

 

hope u dont damage ur engine in this T & E process.
i wud say smthng is definately wrong...............

 

disconnect the battery overnight, reconnect and drive it for a few minutes hard. then park it and wait about 4-5 hours before driving it again, then check to see if the problem is still there. This can be a last resort.

Oh, and the whine isn't that noticeable unless you get on it, i've seen some vids whjere the whine is so loud, but it turns out thats on 6-9 lb pulleys.

 

That's good to know. I went on Youtube to check out what the SC sounds like in other cars, and it sounds louder in the vids. This might also be because of the sensitive effect of the noise being recorded by audio.

 

On this beautiful Sunday morning, 71 degrees, no traffic..

The car was operating beautifully. No idle problems. No nothing..

Wonder if the problem magically went away?

Problem may still reoccur however, Will post pics soon of the vacuum routing..

 

For shits and giggles, check you coolant level and try to purge all the air out of the system. Its possible that a little bit of air is caught in the IACV causing it to think the car is cold and raising the idle while in traffic.

 

+1 and check if all the hoses ( both water and vaccum hoses) are connect correctly. Also check the trottle cable to see if it is binding.

 

I think you might be right.

The coolant level dropped in the overflow, which I think indicates that there WAS air in the radiator and the system over time sucked coolant from the overflow into the radiator to replace the air. But how is air in the cooling system dependent with the IACV? You say that the idle will raise, when the car is hot, because of air caught in the IACV..

Ima handle this tho and refill the coolant and burp the system.


ALSO...

I found a vacuum line on the TB that was kinked because it was not long enough, and the angle caused the line to bend.
It was the vacuum line connected vertically from under the TB.

Does anyone know what this vacuum line is used for? It may provide some insight as to how this is related to my problem as well. Although fixing this kink may resolve the issue I would still like to know the "science and engineering" behind it.

Ima pick up a longer vacuum hose tmrw morning and see if the car acts straight at idle.

 

Under the TB? Under the TB is the IACV with two 5/16" hoses running into for the coolant.

Do you have a pic of the line you are talking about?

 

My wife still hasn't shown me how to post pictures up. Ima wait for her to help me post pics tonight.

But yeah.. "Under" the TB is the TP sensor... There is a vacuum fitting/line, 3/16" next to it. If this line is kinked.. I am not sure what the effects might be.. But so far after unkinking it.. I haven't seen any problems..

The IACV has two 5/16' lines. One is connected to it and the other, next to it, but those are connected correctly as per the Comptech directions....

 

Ok. I wasnt sure how the TB was oriented on the SC, so I was just basing it on the stock location. That vac line you are talking about goes to the purge control solenoid. Autozone, NAPA, Advance or Pep Boys sells 5/16" vacuum or fuel line (fuel line is usually reinforced).

 

Yea yo. I just replaced this vac line (next to the TPS) from the TB to the purge solenoid... The idle fluctuation went away I believe.

The high idle problem still remains.

Again..

Normal when engine cold and driving at 50+mph (since being air/wind cooled)..

But at idle.. and low speeds.. after driving for a while.. the idle rises.. I think to have more coolant flowing thru the engine to prevent it from over heating..

If this is so.. I think you were on the right path when theorizing that the IACV might be getting hot air in it, hence an incorrect reading...

There are two 5/16" coolant hoses from the thermostat housing to the two fittings near the IACV...

One of the fittings (the one facing straight towards the firewall and bends towards the engine).. I can't get the hose to go completely over since it is curved.. Also, I haven't put a hose clamp on it cuz it feels pretty tight..

Although I doubt that the hose is introducing air into the IACV.. You think it is likely that this is the point of entrance?

I don't know anymore..

 

If air was entering in from it, youd see coolant seeping out from it.

Id replace the lines with longer ones that fit over the barb completely and then put clamps on them. Do you burp the system? Pop the cap off the radiator, put a funnel in it, and fill up to the top while the engine is running. Tap on the throttle body alittle to try to move the air (if it is there) around.

 

This is a picture of the vacuum line from the purge control solenoid to the TB

 

You can see the two coolant lines near the IACV

 

This picture shows where the two coolant lines from the IACV are connected. The one vertical is connected to the hose to the left in the picture above. The one horizontal is connected to the hose to the right in the picture above (the one that says Goodyear).

 

Overall picture of the Supercharger installed on the CLS6.
Vacuum line from the Bypass thing to the elbow mounted on the intake manifold.
Wonder if the Bypass Valve is functioning properly.
Any one know how to test?

 

Boost gauge installed?

 

Nah, not yet.

Could a boost guage help me diagnose my problem?

I also have a fuel pressure guage, but also not installed yet.

The Idle rises over time. Starting at the normal 700 RPM upon start up and rising up to 1500 RPM as you drive for a period longer than 10 minutes..

 

Leaky gasket or IAT out of range?

 

Hmm.. There are 4 bolts attaching the blower elbow to the TB.. 3 are tightened down.. but the 1 long one I used a M8 (1.25) pitch 70mm long bolt, which barely, but surely tightens it down.. It may be a point of a vacuum leak.. but the problem is I don't know where to get a longer bolt.

How would you find out if the IAT is out of range?

 

Lowes carries plenty of metric bolts.

 

The IAT isn't particularly picky (you can disconnect the coolant lines to it and it just meters the TB metal temperatures) - but if you disconnect it - the idle goes all over the map. All sensors have a voltage range they report back to the ECU - though I'm not sure the specifics on the IAT. I'd eliminate the leak portion first.

 

I've checked Home Depot and Lowe's and they both don't carry anything M8 (1.25) that is longer than 70mm..

 

I see, I see..

So incorrect Intake Air Temperatures readings can cause incorrect idle..

What other sensors, etc... are related to idle? Just out of curiosity...

 

Well, since the gauge measures vacuum and boost it just might

 

TPS, IACV, and all accessory sensors (HVAC, Power Steering, Braking).

Anything that touches Vac or puts load on the engine (Basically anything electric, electronic, or hydraulic) - has a sensor on it to tell the ECU to give it a little more oomph or back it off a little if not under load to maintain the idle.

 

Haha, true. Will install..

The wiring is a bit complicated tho, but then again seems simple.. Assistance anyone? I don't like trial and error. I like gettin it done right the first time.

Boost and Fuel Pressure Guages each have power and ground... The previous owner spliced here and there..

They also each have a 3 wires going into the connectors..

Where do most connect Power and Ground to? Does each guage need its own power and ground? or can they be spliced together for one connection..

Also.. What is the best way to fish the wires thru the firewall hole on the driver's side?

Any tips? Suggestions? for the easiest install?