[BerthieTW]

Hello Everybody,

I'm new to this forum,

I own a 2002 Saab 93 2.2 TiD 125Hp that has around 230K km (almost 150k miles dunno what kind of units you use...)

I do most of the things I can do on my own on the car, and recently, after a diesel filter change (under the car right next to the right rear wheel) I noticed my car lacked a looooot of power and finally the orange Engine light turned on (the one under the temp, not the Check Engine one)

After the filter change, it was real hard to get the car to start again (all it did was start and stall almost instantly) but after numerous attempts it started again. I took it for a quick ride, but something wasn't right, felt like the car had no guts, even pedal to the metal in second and third gear and then the Engine light came on. It isn't in limp mode cuz I can get it to 120km/h (~75mph).

I checked the fuel tank cap, it's tightened, I tried my OBDII reader, and it couldn't find any fault ! The engine light goes off when I shut the engine off and only comes back if I try to accelerate hard. Car was working perfectly before I changed the filter so I guess it's what caused it...

Could it be a lack of fuel pressure (air entering the fuel circuit somewhere) or residual air from the filter change still in the circuit? Dust in the injectors? Any ideas?

Thanks for reading me and sorry for my english, I'm french

 

[jvanabra]

I don't know anything about diesel Saabs, but on the diesel vehicles I have owned you need to purge the fuel system after a filter change. On both my Jeep and my Suburban there is a specific process to do that. If you don't, air will get trapped in the fuel system and the car (truck!) will not run right.

 

[BerthieTW]

Hey thanks for the answer. Indeed that's a good starting point. I know in this car (and certainly many others) the fuel system is under high pressure. There's two way to get easy "access" to the fuel line. First is the bleed at the bottom of the fuel filter Bowl. But as the Bowl is always filled with diesel, I guess opening it will only let diesel out. The other option is a bicycle-tire like valve in the engine bay right before the fuel pump. I guess if I connect a vacuum pump to it I'll be able to draw in fuel if everything alright, air if there's in the circuit. But if air was trapped within the circuit wouldn't it be expelled via the injectors when I tried to start it right after fuel filter change ?

 

[jbmorse02]

I had a similar problem on my gas 2.0 9-3 recently. Very low power and some misfiring after a filter change. It turned out I had tightened the banjo bolt on the inlet side of the filter carelessly, allowing the fuel line to turn a few degrees and kink, severely limiting fuel flow. The car ran great after un kinking the line! You might want to check that before looking for other problems.

 

[BerthieTW]

I'll try tomorrow to see if I did something wrong when I plugged back the fuel line inlet and outlet after the filter change. Although it seems it's an entirely different filter system, gas has a metallic looking filter that you change entirely. Diesel has a vertical filter box with fuel inlet and outlet (and connection for filter heating) in which you place the paper filter. I'll keep you posted on my attempt to see what's wrong there...

 

[BuHuSPG]

I also know nothing of diesel saabs but have another diesel car and truck. It is extremely important that you prime these properly and different cars have different procedures. You should look up the saab procedure and see if you did it properly.

For example:
On my dodge truck: you turn the key on for about 30 seconds and the fuel system primes with the lift pump, filling the filter and getting fuel to the HP pump.

On my VW: you have to prime the system using a factory computer setting which tells the pump to prime, though some have figured out ways to jumper the pump.

Point is, the processes are model specific but since the diesel lubricates the high pressure pump, you really, really have to make sure you've primed properly or you can damage the HP pump, injectors or other expensive parts. Even by running air through them for a short time.

 

[BerthieTW]

Procedure says it's not necessary to prime, it'll only reduce the amount of time to get her started. What I could have done to accelerate the process according to the manual is vacuum bleed the fuel line of air (service outlet is in the injector pump) it also says the car otherwise dispose of the air itself. If this is right, as my car starts and rides (nicely but not as "reactive" as before) my only option/guess is air is entering in the system thus preventing the nominal High pressure or a fuel line is collapsed due to hose clamp also preventing HP.

 

[jvanabra]

I'd assume there is a test fitting on the pump - you should be able to measure pressure there. It might give you a clue as to the nature of the problem.