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Amazing...I fixed it...surging idle...wouldn't start

3K views 24 replies 4 participants last post by  aaronw 
#1 · (Edited)
I was wrong, the problem is not solved

My '96 900S non-turbo 4 cylinder was idling up and down when I first would start it, the lights would dim and then become bright while the idle was surging, and then today it wouldn't start. The "check engine" light had been on for a while too.

So I replaced the Mass Air Flow Sensor and the Crank Position Sensor. It wasn't too difficult of a job. Once these two parts were replaced I hooked the battery back up and the car started immediately. Also the check engine light was off. I drove the car for about 10 miles to see if anything happened and it ran smooth.

UPDATE:
Car wouldn't start this morning. It has gotten cold here in Southwest Virginia and is snowing today. I think the the reason the car stated last night was because I reset the computer by unhooking the battery for 30 minutes.

I'll continue to search the threads for help, but in the mean time does anyone have any suggestions? Thanks.
 
#2 · (Edited)
Great to hear that. :cheesy:


Other common causes for the surging idle are a dirty Idle Air Control valve and a cracked or unplugged vaccum hose. The vacuum hose can cause a CEL too.

For the record, the CPS doesn't cause these symptoms. The CPS controls the fuel pump aNd if it get's flaky, it won't work hot; this is the reason why the car would start on cold but not if it was just turned off. A bad CPS should be tested hot to make sure it's bad.

On your car, the CPS resistance values should be 650+-50 Ohms
The MAF can be cleaned in most cases. People using too much oil on their open air intake filters may cause the MAF to gewt oil and make problems.

Obviously there are more causes for surges like a dirty sticking throttle plate or cable but those are the main ones.

Congrats on a job well done :cheesy:
 
#3 ·
OK what are the exact symptoms?

Is the car cranking at all?

Do you have fuel to the spark plugs? In other word, are they wet after trying to crank the car?


Do you have spark at the distributor (your car is an S so I'm assuming it's a 2.3 normally aspirated engine not turbo)?
 
#4 ·
Update

Ok, I am still having difficulty starting my '96 900S 4 cylinder. Here are some more details.

New items: 1) fuel pump; 2) fuel filter; 3) spark plugs; 4) wires; 5) distributor cap; 6) rotor; 7) Mass Air Flow Sensor; 8) Crank Position Sensor; 9) Air Induction Valve; and 10) Vaccume Hoses.

This morning I went out to start the car but it would stall after running for 5 seconds. I then disconnected the battery for 10 minutes and then hooked it back up and the car ran fine. I ran a few errands and it started up no problem. What do you think?

I haven't checked to see if there are any codes yet.
 
#5 ·
Secondary Air Intake

The car started this morning with no problems. In a way I am both happy and sad because I am concerned it may be an intermitent problem. Anyway, I got a reading that said secondary air intake.

Is that referring to the pump in front of the driver side front tire that makes a weird noise when you start the car and costs $300.00 to replace and isn't even on vehicles in Europe? Please correct me if I am wrong. Thanks.
 
#6 ·
Yes! That's the part!
 
#7 ·
I was afraid of that.

Thanks Leon for the confirmation. I was afraid that was the part. Before I shell out $300 I'm going to recheck the hose connections to it. But if I have heard the BRRRRRR noise, then I imagine the pump is worn out.
 
#8 ·
Hey! Never mind. This sounds like a post I had earlier. Check it out! http://www.saabcentral.com/forums/showthread.php?t=114160After I turned the small circular check valve the other way, orange part down(located on top of a flying saucer type thing, coming from the tube of the air injection pump) The Brrlappp, noise I was hearing finally went away. I'm guessing when I changed the vacuum hose, I didn't put it the right way. Now your valve may not be actually up and down, because if you have the original piece of hose connecting the valve, it may be longer causing the valve to sit sort of sideways, just turn it upwards and see which color you see. Good luck!
 
#9 ·
The secondary air injection has nothing to do with starting/running qualities...

It is in operation for the first few minutes.. I cannot imagine anyone spending $300 for something that does so little...
 
#10 ·
Yea, I was sort of thinking the same thing myself. If anything, if you've already checked the Idle Air Control Valve, I would suspect the O rings on the black cover that seal the throttle body. If you look at the back of the throttle body, you'll see a metal clip that you can pop off with a flat head screw driver, then lift the cover off of the throttle body then carefully out of the two eyes near the valve cover. Inspect the O rings and relube them as necesary. Hope you figure out what's wrong...
 
#11 ·
What I am going to check now.

Ok, here are the things I am going to check very soon:
1. The rubber gaskets on the black cover to the throttle body are mashed and are probably not making a good seal.

2. The small vacume hose from the throttle body to the PCV valve is too short- when I replaced it I evidently cut it too short- so it causes the valve to bend down when the black cover is on. I bet air is getting in that way.

3. The air hoses that attach to the Secondary Air Pump.

Thanks Leon for your input. I'll keep you updated.
 
#12 ·
Update

Here's an update:
First, I replaced the PCV valve on the top of the engine and the rubber gasket that the PCV valve goes into on the engine. I cut another small hose to go from the throttle body to the PCV valve that isn't short and checked that it wasn't kinked.

Second, I cleaned the o rings on the plastic intake cover that attaches to the throttle body. For the time being I took the mashed one off and will pick up another one at the SAAB dealership in Roanoke this week.

Third, I haven't checked the hoses to the secondary air pump yet.

The car will start up ok now, but the idle continues to surge up and down causing the lights to dim. Also, according to the computer display I am only getting 22mpg when I used to get 26mpg before all this started.

I am going to persevere and solve this though...with everyone's help. I continue to read threads about this issue looking for something I may have missed.
 
#13 ·
Hey aaronw! I was thinking of something. At the top, near your first post, when you said you replaced the Air Induction Valve do you mean the Idle Air Control valve? Underneath the black cover? Next, the fuel filter, did you DIY this? I would check it on both sides to make sure it's not leaking. When I replaced mine, along with the new sealing washers, I thought I had tightened them enough, but apparently I didn't because there was a small leak and I had to retighten them. Lastly, what about the EVAP Purge Valve? Do you think if this is bad you would have idling problems? OOh, no, this is the last thing to check... You know the small plug running from the back of the distributor? The one with the metal attached to it, and to disconnect it you just push the metal down on the plug, then unplug it? When I was checking my rotor the other day, I noticed that all 3 wires coming from that plug were cracked and exposing the bare wires underneath that plastic coating. I disconnected it, cleaned it real good with degreaser, then sprayed rubber PLASTIDIP available at Lowes, to cover the wires back up again so they wouldn't be exposed. Because if you think about it, those small thin wires are pretty much what's telling the computer which cylinder is in the firing order at the moment, so they play a big role in the running conditions.


And hey, I go to VCU in Richmond, but I will be visiting my friend that lives in Martinsville January 3 and wll be staying there for about 2 weeks, maybe I can meet you to take a look at it with you. From the sound of it, you're a DIYer like myself! Take care.
 
#14 ·
Ha! I just keep thinking of things! What about the small vacuum hose that goes from the throttle body to the top of the fuel pressure regulator? When I changed my hoses, that one was severly cracked/brittle when I changed it. Oh yea, and it's also hidden under the fuel rail. You'll have to fish it out. Ok, I think that's it! :)
 
#15 ·
Secondary Air Induction System

I chose tonight, high wind advisory in the Blacksburg, VA area, to get under the car and check the secondary air pump hoses in front of the driver side front wheel. All the hoses looked to be attached and secure, but it looks as if I might have a power steering leak.

So I've checked the 3 things I wanted to, but still the surging idle persists. Leon, thanks for the suggestions, which give me some new options to try. I'll check on the hose that goes from the throttle body to the top of the fuel pressure regulator.

Yes, I have changed the Air Induction Valve. I made sure to install it correctly as I read in a thread where one person put it on backwards.

I have a cousin who attends VCU and is in his first year. I'll be driving to Rocky Mount, VA. on Tuesday January 8, 2008 for a meeting from 10:30AM to 12PM. Maybe we can meet up then? If I don't have the problem solved by the middle of January I might even drive to PA to let Earthworm check it out. LOL.
 
#17 ·
Temp Sensors

No, I haven't checked the temp sensors. I will have to put that on my list. I think I know where one of them is- on the top of the engine in the front? But I'm not sure where the 2nd is, so I'd appreciate it if you let me in on the secret.
 
#18 ·
Yea, the coolant temp sensor is the one with the blue plastic plug, right above the thermostat on the driver's side. the only thing, is that it's in a particularly tight spot! Righ in the intake manifold between the tube going to cylinder 3 and 4 (the last one).
(with the black air plenum removed, you'll see it beneath the wiring mess and the fuel rail.)
I just changed my coolant temp sending unit (operates the gauge in the car) also the one you see right in the middle between one heater hose and the upper radiator hose on the head.


But yea, right on. I'll have to make sure that we're not doing anything that day, but I can possibly meet ya. So from 220, go north and take like the first rocky mount exit? Like going to Smith Mountain Lake?

You know, one last thing I was thinking about, did you DIY the pump yourself also? I remember someone posting about their car cutting off, and found that the wiring in the pump assembly was shorting out, but his car would always blow the fuel pump fuse. You're not having that problem, are you?

Lastly, can you explain exactly what the car's doing recently? Is is the same as above, in the first few posts? Thanks. Hopefully you'll find the problem!
 
#19 ·
What the car is doing now

Tonight when I started the car the idle began to surge and it almost stalled twice, but then the idle leveled out and it ran fine. The problem isn't bad yet, but I want to fix it before it becomes a problem.

North on 220 & take the first Rocky Mt. exit is correct.

The fuel pump, and fuel filter I did not do myself. I don't mess with gas.
 
#20 ·
Hmmm, well after you check all those things, does your car have a cold air intake (ie aftermarket filter)? If not, just check the air filter, make sure it's not clogged or something is in there...:eek: My old car, 1992 Galant, when I changed the air filtet, in the area were a whole bunch of acorns, lol!! Maybe asquirrel was trrying to make a home for the winter? :roll:

What has me concerned is the dimming of the lights in your car. Does this occur to the headlights also? what mileage does your car have? Maybe it's time for a new alternator or just the brushes, that's available at eeuroparts.
http://www.eeuroparts.com/productdetail.aspx?searchResults=1&code=5034

Just check all electrical connections, you never know! Push on them all! LOL.
Man! This is a tough one! :) You'll get it!
 
#21 ·
Check Engine Light Code P0411

I went to Advanced Auto Parts this evening and had them do an OBD II scan of the ECU in my '96 900S with 1615??miles. Here is what the code read: "P0411 Secondary Air Injection System Incorrect Flow."

So I've already changed:
1. Vaccume Hoses to the Secondary Air Pump from the Throttle Body.
2. Vacume Hose from the PVC Valve to the Throttle Body.
3. Mass Air Flow Sensor.
4. Crank Position Sensor.
5. Air Induction Valve.

I had heard some GRRRRing noises prior to all this, so I'm wondering if I need to purchase a Secondary Air Pump. Initially I was opposed to this since it only runs for a short time while the car is idling after first starting the car, and I thought I could get by without it. But now I'm not sure.
 
#22 ·
LOL! Aaron! Did you check the picture in the earlier post I sent you? Look for that check valve atop of the flying saucer type thing (directly below the upper radiator hose, I posted a pic) and turn it the other way!!!;)

Here! http://www.saabcentral.com/forums/showthread.php?t=114160

Be aware, there is a 2-3 inch hose connecting this check valve on the bottom to the flying saucer type thing, okay? Let us know how it goes!
 
#24 ·
Oh man... I guess I would susect the thing underneath it? The "flying Saucer" type thing is a check valve of some sort also, right? :roll:
 
#25 ·
It's fixed

Yesterday I replaced the Secondary Air Pump, which took about 45 minutes. Afterwards I started the car and listened and watched for the surging idle, but it never happened. The Secondary Air Pump kicked in and the car's idle remained constant.
 
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