poor power issues [Archive] - SaabCentral Forums

: poor power issues


boxman
31st July 2008, 08:21 AM
OK so I'm having an issue with my Abbott tuned 9-3, the engine runs as smooth as silk after replacing the head gasket, I have looked over the car and can find nothing untoward but i am having a problem which is concerning me now, at low revs the car is fine boosts well and performs as you would expect but as soon as i push the revs up to about 4k i loose power so much so that the engine will not pull past 4k with out a struggle (I'm sure i could run faster) most of the time when this happens the boost tails off right back to base boost but some times it stays boosting but even then there is no power, i have no fault codes stored and no over heating or pinking just a lack of power.


at this moment I'm thinking it could be a fuel pressure issue or fuel delivery issue, so i may have to remove the pump :evil:


do you guys have any ideas ;)

ragtopcav
31st July 2008, 06:55 PM
Essentially can only be fuel or ignition.

Our stg 3 9000 pulls very strong to 5300rpm and then starts to gently drop off, I should imagine most of the more conventional chipping packages, like a standard Abbott, are not dissimilar.

How to measure though? The WIS does have instructions for measuring the delivery ability of the fuel pump, would this be any good?

David in Tallahassee
31st July 2008, 10:15 PM
OK so I'm having an issue with my Abbott tuned 9-3, the engine runs as smooth as silk after replacing the head gasket, I have looked over the car and can find nothing untoward but i am having a problem which is concerning me now, at low revs the car is fine boosts well and performs as you would expect but as soon as i push the revs up to about 4k i loose power so much so that the engine will not pull past 4k with out a struggle (I'm sure i could run faster) most of the time when this happens the boost tails off right back to base boost but some times it stays boosting but even then there is no power, i have no fault codes stored and no over heating or pinking just a lack of power.


at this moment I'm thinking it could be a fuel pressure issue or fuel delivery issue, so i may have to remove the pump :evil:


do you guys have any ideas ;)

Could the timing chain have been installed a tooth or two off during the project?

I had this happen on a Porsche 944 once and it exhibited the same type symptoms.

D-

Shirozina
1st August 2008, 02:43 AM
A blocked CAT could cause such symptoms as it could just flow enough at lower RPM but become very restrictive at higher levels. When I was at Abbott last week they checked the CAT by undoing the joint just behind it and moving the pipe aside so I could look inside and see the core - it was intact and clean. If you are not getting fuel or the ignition was faulty I would have thought this would throw a CEL very quickly.

boxman
1st August 2008, 08:16 AM
A blocked CAT could cause such symptoms as it could just flow enough at lower RPM but become very restrictive at higher levels. When I was at Abbott last week they checked the CAT by undoing the joint just behind it and moving the pipe aside so I could look inside and see the core - it was intact and clean. If you are not getting fuel or the ignition was faulty I would have thought this would throw a CEL very quickly.

interesting thought, i had dismissed the cat due to a recent MOT pass, but i could put my old catless pipe on to see, this will at least eliminate this as a possibility


Essentially can only be fuel or ignition.


How to measure though? The WIS does have instructions for measuring the delivery ability of the fuel pump, would this be any good?


i have the wis (you gave me a copy a few years back) so i'll take a look cheers for reminding me

NickTaliaferro
1st August 2008, 09:29 AM
I would guess cam timing. Unless you missed a simple one like a signal ground wire.

boxman
1st August 2008, 10:51 AM
this prob was there before the head gasket was done, thats why i did it, thought it was my prob' and i am all to aware of incorrectly timing the cams :) all wiring checked more than once :evil: doing me head in :roll:

appreciate the thoughts tho' guys keep them coming

hkayssi
1st August 2008, 12:17 PM
Sounds like a fuel pump having a problem under heavy acceleration.

http://www.saabcentral.com/forums/showthread.php?t=127883


Use an A/F gauge. Check what JZW did
http://www.saablink.net/forum/showthread.php?t=19282

boxman
14th September 2008, 07:00 AM
A blocked CAT could cause such symptoms as it could just flow enough at lower RPM but become very restrictive at higher levels. When I was at Abbott last week they checked the CAT by undoing the joint just behind it and moving the pipe aside so I could look inside and see the core - it was intact and clean. If you are not getting fuel or the ignition was faulty I would have thought this would throw a CEL very quickly.

and today's prize goes to Shirozina, removed the cat from the car yesterday and the car now runs like it used to, so I guess I need to speak to Abbott again, they had to replace me intercooler last week now this ;oops:

Shirozina
14th September 2008, 09:13 AM
Abbott have had problems with their CAT's - mine repeatedly failed it's MOT and I'm sure it was due to the inefficeincy of their tiny race CAT. Mine was absolutley clean though as we looked through it on the ramp. If it's blocked it's likely to be a fault with the ignition and or fueling though which has caused the problem rather than the CAT itself. It may be possible to clear it by running it hard and burning off the deposits. Why did they replace the IC? if it was oil contamination this will also foul the cat.

boxman
15th September 2008, 03:30 AM
the intercooler was replaces due to the capillary tubes on the top row ballooning, it does seen strange that the cat has blocked, if its a tuning fault why didnt the stock cat fail too?