Air filter box removal/ replace w/ cone filter

[onthesolidrock]

Alright, so I've got an update on my car........

my belt tensioner strut was snapped, but wedged up against the A/C compressor enough to keep the belt tight, but loose enough to cause some problems with my head lights and cooling fans and so on.... had the alternator tested and it checked out with flying colors. so I've just finished replacing the tensioner with a new belt along with new spark plugs, no issues with having all my electronics turned on at the same time.... I'm happy about that, I'm not happy with my dash light, the battery light to specific, it still stays on unless i rev the engine to about to 1,200 rpms then it fads out and stays out.... is this common?

I've decided not to go with a cone filter however my the filter box is still out of the car because the gasket between the box and the air "do dad" (the correct name escapes me right now) was broken so I'm waiting on a new gasket to show up in the mail..... I strongly doubt it, however, would that cause an issue with that light in any way?

[djnolan]

If your battery light is on something is not right. Check the following with a digital volt meter or using the dash gauge:

1. battery voltage engine off should be 12.7 volts if the batter is fully charged, a little less (12.3-12.5) if the batt is partially charged or old.

2. Battery voltage with the engine idling and accessories off (lights/ A/C, etc) should jump up to around 13.5 or so.

3. With the accessories turned on and engine idling the voltage should hold steady at 13.5 or so.

Let us know what you find. Use a digital volt meter if you have one, as it is more accurate than the dash gauge.

[onthesolidrock]

So heres what I found with my digital volt meter....

engine off with no accessories on, battery 12.85 (less than 6 months old)
engine idling but with battery light still lit with accessories off 11.8
engine idling but with battery light turned off (i tapped the gas a little for it to fad out then let it idle again).... 13.9
engine idling with A/C, head lights, fog lights, interior fan, rear defroster and 4 ways all turned on, 13.25

the car was stone cold by the way, its been sitting in a garage all week at about 20 degrees. i did not warm up the engine what so ever before I took these readings.

not sure if it helps any but the car idles around 850 to 900 rpms when cold, when warm idles around 1,100 rpms.

[Jfrahm]

If the belt is tight and the connections are correct and tight then the alternator is not working properly.

[flash968]

on the voltage issue, i'm guessing voltage regulator. they wear out.

it should not idle higher when warm. in fact, if anything it should idle higher when cold. that's a whole different issue you have going on there

[Tom944]

I am not sure about the 944 but I have had a similar battery light issue on other cars. From what I recall the battery light is in the exciter line to the alternator. The input to the bulb is 12v so that when the alternator is not running you get 12v across the bulb and it lights. When the alternator starts (the 12v on this line is required for this) it puts out 12v (or so) and the light goes out since there is no voltage drop across the bulb. I found that a coroded connection to the alternator from this line caused this issue. If it gets really bad the alternator will not work. I hope that this helps.

[v2rocket_aka944]

Originally Posted by flash968

on the voltage issue, i'm guessing voltage regulator. they wear out.

it should not idle higher when warm. in fact, if anything it should idle higher when cold. that's a whole different issue you have going on there

on the early 944 they don't have a "cold fast idle" so they do vary the speed based on temperature...simple bimetallic spring in the auxiliary air valve to bypass the throttle plate, not even controlled by the ECU.

typically cold they run at 700-800 and warm 900-1000 depending where it is set to.

[azbanks]

If the tensioner rod snapped, check both AC mounting bolts. Mine snapped because the back mounting bolt had snapped and that let the AC unit twist enough to snap the tensioner. I went through 2 tensioner rods before I figured it out.

[flash968]

every engine on every car legally brought into the US since about 1978 has a cold fast idle. it's due to emissions. if it doesn't idle faster cold than warm, then something is wrong or modified.

[onthesolidrock]

last year I over heated my car pretty good, i blew out my oil cooler seals in the process.... ever since then the car had a hunting idle issue once it warmed up. it did idle high BEFORE it over heated. after chasing down one thing after another trying one thing after another I got fed up with it. I found that by adjusting the small screw next to the throttle cable a few turns lessened the hunting idle, so I just kept adjusting it down until the hunting idle stopped. I know that isn't the correct thing to do but its been running just fine, it does start hard sometimes when its hot but nothing serious. whatever caused the hunting idle hasn't been fixed i'm sure of that, adjusting that screw just masked the problem for the time being. so that explains the cars lack of a high idle when cold....

[flash968]

hunting idle and high idle tell me vacuum leak

[onthesolidrock]

I thought it was a vacuum leak too but 30 minutes and a can of parts cleaner later i couldn't find any. I let the engine idle and spray the parts cleaner around all the vacuum lines and it never revved up or effected the running of the engine.

[flash968]

use a guage. could be at a valve, head gasket, yada yada. you should get a solid reading of not less than 17 inches at idle (per workshop manual of 900 +/- 50)

[Tom944]

Originally Posted by onthesolidrock

I thought it was a vacuum leak too but 30 minutes and a can of parts cleaner later i couldn't find any. I let the engine idle and spray the parts cleaner around all the vacuum lines and it never revved up or effected the running of the engine.

I've never had a lot of luck with that approach on these cars. I've had most luck finding leaks with a half inch plastic tube held to my ear whilst probing around with the other end. Remember to probe around the intake gaskets.

[flash968]

just use a gauge. that is really the only way to definitively determine if you have a leak, and what kind. every backyard mechanic should have one. it's the single best tool for diagnostics.

[onthesolidrock]

Today I took the Electric Air Valve (small valve in the vacuum line that mounts behind the air box) i took that out and cleaned it. cleaned the connections on my Auxiliary Air Regulator (idle Control Valve under intake manifold), cleaned the connections on my radiator temp sensor and the DME coolant sensor, put a little grease on all the terminals. if i back out the screw next to throttle body a few turns i still have the hunting idle issue... a few forums I've found talking about this issue is to spray parts cleaner or carb cleaner into the J-boot while the engine is running to trying and clean out the ICV.... which i gave that a try and no luck.... now the Electric Air Valve (behind the air box) does work, i touched a 9 volt battery to it while out of the car and blow air through it with the battery on it... however with the car running from cold to hot enough the fans kit on the leads that plug into it don't put out any power....

I can't think of any way to get to the ICV with removing the intake manifold, i would like to take it out and clean but really really don't want to remove the intake manifold just do so... is there a way? anyone have and solve this problem before?

[9FF]

Originally Posted by onthesolidrock

...I can't think of any way to get to the ICV with removing the intake manifold, i would like to take it out and clean but really really don't want to remove the intake manifold just do so... is there a way? anyone have and solve this problem before?

IMO removing the intake manifold is probably the most satisfying and productive jobs you can do on these cars, plus it's really cheap to fix a lot of stuff wyit and so easy to do.

Buy some LR silicone vacuum hose, new AOS seals and new intake gaskets before you start. Some good quality stainless hose clamps in various sizes would also be handy and some small brushes, solvent and rags for cleaning under there. It should take you no longer than half a day and take plenty of pics with your phone as you take things apart.

You will feel much happier knowing everything is in good shape under there. GL

[flash968]

not sure it it's the same or not, but on the 968 the ICV is underneath the intake manifold, held in place by a clamping bracket. after disconnecting the hoses and electrical connector, you loosen the big bolt on the clamp, and slide the ICV out.

but i agree about feeling better by removing everything and renewing it.

i would still put a gauge on there first. if you have a larger problem, you will only frustrate yourself by doing all of that work, and still not solving your problem

also, both the bosch hammer and the durametric have an ICV test

[djnolan]

Agree with the vacuum gauge, and then a smoke test to find where the leak is...

[Jfrahm]

Is that a cigar jammed into a $5 Harbor Freight transfer pump? That. Is. Awesome.