Loss of power

Tiny
MYINVESTMENT
  • MEMBER
  • 1998 SAAB 9-5
  • 158,000 MILES
This has been a problem for a while now with my saab 9-5 2ltr 1998.

The car starts and runs fine with no problems. However when I approach a steep hill the speed drops from 80 to about 55mph and doesnt pick up again until its back on the flat road. Also it hardly goes over 80mph on the flat. These cars are capable of over 110mph if im correct. Overtaking can be a dare sometimes.

Ive renewed all vacuum hoses, cat converter, oxygen sensor, regular oil change, fuel filter. Fuel pump etc. The problem still persists.

My only other thought is the fuel injectors may need ultrasonic cleaning.

if anyone can shed any light on the problem it would be very appreciated.

peter.
Wednesday, September 21st, 2011 AT 5:05 AM

10 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,896 POSTS
Have you tried running a fuel injector cleaner through it?
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Wednesday, September 21st, 2011 AT 5:07 AM
Tiny
MYINVESTMENT
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  • 16 POSTS
Hi no I haven't tried yet I was wondering if it was worth getting the injectors cleaned professionaly. Do the injector cleaners work?

Thanks
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Wednesday, September 21st, 2011 AT 11:13 AM
Tiny
MNTHNY4
  • MECHANIC
  • 612 POSTS
Does the engine rev's out to red line, u say u changed cat, fuel pump etc, did u do a fuel pressure check while going up hill, if not get that done, if fuel pressure is ok while doing test & cat is good then u may have a issue with your transmission, some info is missing here from u, is your check engine light on, did anybody mess with the engine timing at all, post back with info.
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Thursday, September 22nd, 2011 AT 5:37 PM
Tiny
MYINVESTMENT
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  • 16 POSTS
Hi, thanks for taking the time to reply. No the engine revs at 80 are about 3000. Not done a fuel pressure test, dont know how to. No check engine light. As far as I know no one has messsed with the timing. I must add the car has never failed to start 1st time even in winter, runs perfect apart from the power loss on hills, it also takes a while to from say 70-80 other cars I have had reach top speed pretty quick.
It's all a mystery to me.
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Thursday, September 22nd, 2011 AT 6:46 PM
Tiny
MYINVESTMENT
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Can you tell what problems I might have with transmission?
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Thursday, September 22nd, 2011 AT 6:49 PM
Tiny
MNTHNY4
  • MECHANIC
  • 612 POSTS
Ok u will need to check if the turbo waste gate rod is attached or fell off, sound like u have a turbo issue not boosting up, check that and post back.
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Friday, September 23rd, 2011 AT 12:28 AM
Tiny
MYINVESTMENT
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Hi yes the turbo wastegate rod is attached, not come off!
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Friday, September 23rd, 2011 AT 1:01 AM
Tiny
MNTHNY4
  • MECHANIC
  • 612 POSTS
You may need to check with your dealer for repairs, thats a somewhat hard one to diagnose from a distance may need a hands on approach for repairs to check ecm's function, due to the fact that u said u replaced most major parts dont know if cat was new or used that u replaced, but u may have to bit the bullet & take to dealer or your mechanic for repairs, sorry, good luck. Again get a fuel pressure test done while driving, to check pressure there is a test port in the middle of the injector rail to screw pressure tester onto, u can buy one from a parts store for cheap, just tape gauge to glass while driving & check if pressure drops under 36psi when going up hill.
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Friday, September 23rd, 2011 AT 2:03 PM
Tiny
MYINVESTMENT
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Hi, thanks for you help. I will do the fuel pressure test first. When you say 'tape gauge to glass' what do you mean?

I'll let you know the result. If pressure falls below 36psi do I assume its the pump?

Thanks.
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Friday, September 23rd, 2011 AT 5:07 PM
Tiny
MNTHNY4
  • MECHANIC
  • 612 POSTS
The fuel pressure gauge if the hose is not long enough to reach inside car then u will need to tape to glass while u are driving & going up hill to read gauge, good luck.
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Saturday, September 24th, 2011 AT 9:30 PM

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