Mechanics

LOSS OF POWER

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.
Avatar
Myinvestment
September 21, 2011.




Have you tried running a fuel injector cleaner through it?

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

Tiny
Myinvestment
Sep 21, 2011.
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.

Mnthny4
Sep 22, 2011.
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.

Tiny
Myinvestment
Sep 22, 2011.
Can you tell what problems I might have with transmission?

Tiny
Myinvestment
Sep 22, 2011.
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.

Mnthny4
Sep 23, 2011.
Hi yes the turbo wastegate rod is attached, not come off!

Tiny
Myinvestment
Sep 23, 2011.
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.

Mnthny4
Sep 23, 2011.
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.

Tiny
Myinvestment
Sep 23, 2011.
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.
AD

Mnthny4
Sep 24, 2011.

AD