900t with a problem

[roberto]

Hi all, I have a 1988 900t which has a problem when accelerating. Under normal driving the car is great, will cruise at highway speeds with not a problem, but, when accelerating hard the turbo kicks in and you get that great feeling of power but then just as the gauge approaches the red it feels as though something is holding the car back, lift your foot slightly and accelerating is back but it feels like driving a non turbo car. Any ideas?. Robert.

[peva]

Sounds most likely a fuel supply problem. My first guess is a failing fuel pump and be wary of this because it can let you down and fail completely and not start. Do a fuel pressure test. This is best done with a gauge on a long hose that is attached with an extra banjo to the end of your fuel rail. If the hose is long enough you can tape it to the windscreen and if the pump is failing you will see the pressure drop as you apply throttle and get boost.

[roberto]

Hi Paul, thank you for your prompt reply. I will pass this on to my mate who works on my car for me as I am not at all competent on mechanical problems. Would replacing the pump be a difficult job?, I live in a small community in Canada where a Saab is not too often seen and finding a knowledgeable mechanic willing to work on one difficult. Getting parts is O.K. so it might be cheaper all round just to replace the pump, what do you think?.
Regards, Robert.

[peva]

I would lay money on this being the pump. Probably just as well to replace it. It's not exactly a difficult job. There are plenty of threads around on replacing the pump and it's readily available.

[Badwolf]

While it could be the pump, the black-box APC module does put the kibosh on going into the "red zone" from what I understand. The red APC box allowed a little entrance into the "red" zone. You might want to check around - you might just be hitting some sort of performance wall that comes with the stock black APC module.

[euromobile900]

Could possibly be plugged filter, as well. You never know. Easy to replace the filter and see if it gets better. Then go through and make sure you don't have any vacuum leaks (check the brake booster and the line that goes from the manifold under the windshield to operate the climate control flaps; these are the most common). Finally condemn the pump. They are easy to change. I recommend doing it yourself. You have the older, more robust type, which is less prone to failure and is also more expensive.

[roberto]

Thank you for your reply. I shall be ordering a new fuel filter to see if that makes a difference, this seems to be the cheapest place to start, wish me luck, who knows, if it works then one day I will turn up for a meeting and meet with all the kind members who have tried to help.
Best regards to all, Robert.