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Discussion Starter #1
Hi, new to this forum !

I bought a 9-3 SS Aero 2003 a month or so ago, tonight I picked up a PPC and installed it, on the way back it was fine until I booted it in fourth and it started stuttering.

Car has 46,000 miles and no known issues, only other mod is a Pipercross panel filter.

I tried it again and pretty much every time I accelerate it does this stuttering and you can hear it dumping boost pressure, I kept my foot down in third and it flashed me the engine check light for my trouble.

Any idea what is going on ?

My theories are its currently running on nomral unleaded so it may be detecting knock, perhaps it needs some better petrol, Super Unleaded but I was sure I read that you can run them on anything but lose performance.

Its still learning ?

The wastegate spring is weak.

Leak elsewhere

It was running fine at first after a couple of explorary prod of the acellerator it felt a lot better, quicker, more responsive and I was impressed, now I am worried that there is a problem.

Weather is about 10C and damp.
 

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Could be a fuel issue. Try a couple tanks of premium and see.

Also Spark plug age? Should be changed around 30K miles

Maf might be oiled down a bit from the filter. Usually from over-oiling when cleaning. Or oiling it wet can be bad too.
 

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you should be running 91 Octane MINIMUM. Dont be cheap. The injectors like the higher octane. You will also notice better response using it as well, and better fuel economy.

Also I agree with checking on the ignition system. Check spark plugs, find out when they were last changed, that could have a factor on misfiring, and poor performance.

Try this and Im sure you will notice a difference.

BTW. What was the code that came up for the check engine? That would help out when posting for help.
 

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ok, upgrading software on a car will reveal the weak spots almost straight away if any.

I am going to go blind on this one, but go take a look at your coil packs. I am saying this from experience... personal experience. Check out the number of misfires from each cylinder.. you'll notice one cylinder with more misfires than the rest.
change it out.. and you'll notice another one with more misfires.. it could be time to change out all 4.

sparkies, if you change regularly, shouldn't be an issue.

3rdly, check your air piping. there could be a leak somewhere.

to save time, do it in the order I suggested. to save money, do it in reverse.
 

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Discussion Starter #6
Hi, cheers for the replies.


Ok, dont know when the sparks were last chaged, will buy a set.

Fuel was 95 RON, about a third of a tank left and I topped it up with 98 RON.

How do you check the code, it just lit the engine symbol on the dash, flashed it for a few seconds and then off ?

How do you check the number of misfires ?
 

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Sounds like you are getting misfire under load. The loss of power (boost) is the engine responding appropriately.

The possibility of spark problems should be considered and fouled MAF as mentioned above.

In any 2003 the SAI check valve should be inspected for leaks. This will recirculate exhaust gases once it fails. This is a wear-and-tear part present only on MY2003 93's, and we are getting more frequent reports of failures.
 

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Discussion Starter #8
thanks for that, will investigate, have ordered some plugs, like Dach said I will do it in reverse, it runs ok for the most part and I only do 14 miles a day down slow and windy lanes so not too critical to have 250 bhp.

Have to say, otherwise I am impressed with the change.
 

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Hi, and welcome,


just another though wrt better fuel.

Avoid supermarket fuel like the plague - I belong to my Unions forum - there is a chap there whose family business is several garages across the North West of England. Whenever they strip an engine, apparently it is obvious to his mechanics which engines have been running on supermarket fuel (even the high RON stuff) and which have been using known-brand stuff, BP, Shell etc. The supermarkets keep their costs down by limiting the amount of detergents (if any) they add to the fuel. (Oh, his garages don't sell petrol, so he has no axe to grind.)

He showed some pictures of injectors that had been using cheap stuff for a few months and compared them with injectors that had been treated to 'the good stuff' - the difference in spray pattern and 'misting' was remarkable - enough to convince me never to attempt the false economy that is supermarket fuel.

I have no idea what fuel the previous owner of your car used - but a few tanks of 'the good stuff' might help. Personally, I use BP Ultimate, or Shell V-power whenever I can get it.

HTH,

Phil
 

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Discussion Starter #10
Phil, am with you there, was doing a long commute on my last Saab and got better milage and performance using Shell, I thought it was fluke or a placebo type effect but I repeated it againt Tescos fuel and it was predictable that I got an extra 2/3 mpg on Shell Normal unleaded, I only fill up at a Supermarket if I have no choice.
 

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wtfwill said:
one other thing it could be is a loose or slightly torn hose that connects the turbo.. i remember reading on these forums a few guys who upgraded to stage1 and blew a hose or two because of the increased pressure.
That's the hose connecting the turbo to the intercooler. On some cars the coonection of the flex pipe to the intercooler was loose (clamp not tight enough). Typically the whole hose separated and the car went into limp mode instantly. Two reports of this I do recall.
 

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fuel additives are also helpful cleaning the injectors.

Unless you want a full treatment, most dealers offer injector cleaning.

In which they normally tap into a fuel line and run a machine.etc etc etc.

Apparently does great results on older mileage vehicles. But if your saaab is newerishhhh i wouldnt bother for now.
 

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Discussion Starter #14
Ok, checked the tubing, seems ok as its still reasonably new, couldnt get any plugs today.


Resynced the PPC, the reprogrammed the car as BSR suggested, doesnt seem to have made any difference.

Can anyone let me know where this SAI valve is ?

The MAF sensor I assume is the one just up from the air filter casing, had a look at that, tiny thing, didnt touch it, it looked pretty clean, there was also a sensor down in the right hand side of the engine bay plugged into one of the air hoses, whats that one ?
 

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J4CKO said:
there was also a sensor down in the right hand side of the engine bay plugged into one of the air hoses, whats that one ?
I think this is IAT (intake air temp). Rest assured someone will correct me if I'm wrong.

There are SAI threads in the FAQ. Here's one:
http://www.saabcentral.com/forums/showthread.php?t=94118

The SAI check valve is the flying saucer looking thing in front of the coolant overflow tank and behind the power steering pump (right side of engine as you face car).
 

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Coil packs

Id agree with the gentleman that said the cassette/coil packs. I too, had a bad coil and had the same symptoms under load. A new coil pack under warranty fixed all issues and have had nothing but smiles since.


Drew
 

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I would put my money on it being a boost leak. The BSR upped the pressure so it could have caused a weak area to fail. I experienced similar symptoms on my Impreza and it turned out to be a crack in the turbo induction pipe. It was fine up to 8psi but would start to go haywire with any more boost.
I tried the above things, MAF, plugs, wires, coil, injector cleaning, cam and crank sensors, but nothing worked until that pipe was replaced.
You say you can hear the pressure loss; that could be air escaping to atmosphere given all sorts of metering problems for the ecu.
 

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Aspen said:
I would put my money on it being a boost leak.
Agree this is possible/likely.
Knowing the error code would help. I would expect a misfire code with the high pressure boost leak.

Lose boost --> less air mass --> A/F mixture too rich --> misfire under load
 

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If it was stuttering as opposed to engine shaking and dying, I would say its a boost leak somewhere. but if the stuttering with engine shaking and misfiring, I would say its the coil pack.
 

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Discussion Starter #20
If it were a boost leak, wouldnt it show up across the rev range ?

Its going to be slow going, the plugs wont arrive for a week, couldnt go near the car this weekend due to the British weather, literally it has been raining for about a week. Had a quick look and started an oil change and then realised my dad had borrowed my axle stands again, by the time he had returned them it was lashing down again, then it goes dark at about 3.30 pm, then I am at work all week, repeat until spring.

When I do the oil change I can get it on stands and check the boost tubing a bit better, there di seem to be play in the one under then engine come to think of it.

Have decided not to fret about it, my Fiat Coupe nearly drove me to a nervous breakdown, but that was consuming masses of engine oil, this I will just drive to avoid the problem and methodically go through all the suggestions.

Cheers for all the theories !



Any idea as to how to read fault codes ?
 
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