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Discussion Starter · #1 ·
I have a 1990 9000i 2.3 auto, with direct ignition. For as long as I can remember, this stupid car has had a problem with the revs dropping either at idle or while creeping with my foot off the gas.

What happens is that the revs will drop to near stalling (the tachometer reads about 100-200 rpm), and then shoot back up, to around 1500rpm. It sometimes does this just once, or in rapid succession. Most common to occur when coming to a stop uphill, or while creeping with my foot off the gas, and partly on the brake.

I have cleaned the entire intake system, replaced the IAC valve, checked and rechecked for vacuum leaks (yes, I had a mechanic check too), I have cleaned and re-cleaned the throttle position sensor (including the electrical contacts), and cleaned the injectors and entire fuel delivery system. One thing I notice is that with the key in the ON position, the check engine light will flash 5 times, then pause, and flash 5 more times. I don't know if that's significant or not...

Help! I hate my car right now!!!
 

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Rocky,

Here are the flash codes for your car (and other to 1993)

DI/APC flash codes:

2 flashes - ROM check (check sum check)
3 flashes - Watchdog (control module fault). This fault can also be caused by a defective spark plug or defective ignition discharge module.
4 flashes - Knock sensor (no signal or signal incorrect)
5 flashes - Engine load signal from LH or pressure from the manifold absolute pressure (MAP) sensor incorrect.[/b]
The problems you have do sound like the load may not being sensed correctly...


Also, for reference the trionic ones for 93/94 on cars.

2 flashes - MAP sensor
3 flashes - Intake air temperature sensor
4 flashes - Coolant temperature sensor
5 flashes - Throttle position sensor
6 flashes - Oxygen sensor (lambda probe)
7 flashes - Fuel-air mixture
8 flashes - EVAP valve[/b]
Andrew
 

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Discussion Starter · #3 ·
Ahh, thank you! Ok, this clears up a little confusion on my part...

Now that I know that it's likely the load being sensed incorrectly (sounds bizarre doesn't it?) what can be done about it? My manual says that the direct ignition system has a pressure sensor (for the engine load), so could that be it? (and is this different from a MAP sensor?)

Is there a quick and easy way of testing this part? And if it's broken, is it expensive to fix? Or, should I save up for another car...

cheers,

Rocky
 

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Discussion Starter · #5 ·
Ok, at the risk of looking like I'm talking to myself, I found a new MAP sensor on "thesaabsite.com", for about $100. Ok, not as terrible as I had thought! Now, what I want to know is, is it worth it to get a new one and install it? Or, should I get the system tested out first... this is my dilemma...
 

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What I suspect is being advertised is the pressure measuring device commonly known as a MAP sensors (part # 91 32 374)and was fitted to MY93- Trionic cars, so you won't have a home for it on yours

However, there is a pressure monitor that is used by the LH system (part # 85 94 632 non cat, 85 65 855 cat). I must admit, I thought it was just used for overboost protection and given the situations you describe the fault happening, it's unlikely that there will be any boost pressure of note, and thus it is perhaps more likely that it is a problem somewhere in the LH system. I'm afraid I can't offer any more than that. Perhaps someone else will have had similar problems.
 

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Purely guessing here...

"Engine load signal from LH" Doesn't LH stand for the German for "heated wire", i.e. the AMM? I am sure I recall that a bad AMM can cause an irregular idle.

It may be worth checking the electrical connectors to the AMM which I think are prone to corrosion, and perhaps blasting through it with carb/injector cleaner - be careful though, the wire filament is very fragile! Don't use an air line


If all else fails, I think the usual way - as with so many things - is to try a known good one, if you can borrow one.

I could, of course, be totally wrong
 

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The system operates on "closed- loop" until it's warm, ie does not take any input from sensors but relys on pre-set info. That is perhaps why the faults not there when cold. I understood that MAP stood for Manifold Absolute Pressure which would indeed measure load: more load= greater depression( vacuum) in the inlet manifold ) not sure what happens in a turbo mind because it's positive preassure int it? )
Is your speedo OK. The system boosts the idle speed above 10mph to prevent stalling.Unlikely cause though.
Good Luck , this kind of fault can ruin a relationship
Wul
 

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Discussion Starter · #10 ·
Well, I thought it might have been the air mass meter too, so I gave it a couple (on a few different occasions) blasts of intake cleaner (aka carb cleaner), and put it back in. It made the car run a little better (operative word "little"), but didn't fix the problem. I'll try cleaning the electrical contacts tonight, since, hey, who knows... they might be corroded...

As for my speedo, it's fine, I sometimes have problems at very low speeds (below 10 mph), where it feels like it's in too high a gear. Maybe it's just a slow transmission, or maybe it's related. I don't know. Anyway, you're right about this sort of problem ruining a relationship... I want to love my car; I mean, it's a really nice car aside from this, but it's hard to love it when it's irritating me to no end!



Rocky
 

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Discussion Starter · #11 ·
Hey, I was just trying to clean out the electrical contacts for the air mass meter, and I noticed something. The air mass meter has 6 prongs. My connecting plug only had 5 electrical "female" contacts. It looked almost as if the one on the far left (that would be the end closest towards the front of the car) was missing, or broken off. I'm going to try to find a replacement piece of metal, and see how that works. If this is the cause of the problem, then I'll be pleased and yet grumpy at the same time!

Am I on the right track here, or am I chasing a wild goose?
 

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Disregarding the fault code for the moment (might be a completely separate problem), the symptoms sound like those of a faulty turbo bypass valve. I know you've had the system tested for vacuum leaks, but possibly worth a go? They're quite cheap.
 

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Discussion Starter · #14 ·
It's normally aspirated, not a turbo. Good thought though.

Yeah, the more I read about this, the more it sounds like a problem related to the LH system. Where, I don't know. I'm about to get rid of this wretched car and buy something made by that "other" swedish car maker...

All I have to do is get some money... sigh...


ps: I think this may have been the reason why the last owner sold the car... (of course, I'm only speculating)
 

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i am not an expert, but my car had a problem with the tickover rising and falling. i found the problem to be the idle co2 mix. on my car 1997 9000 there is a small nut with a screw in the middle, it is on the inlet manifold. i was told to screw fully out, then back in 3/4 of a turn. it solved my problem. i hope it helps you.
 
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