No Accelaration Hi I'm having a prob with my 2000 9-5s, when i accelerate hard the engine rev's out and gets stuck at 4000 rpm with no acceleration at all. Anyone know what the prob might be???

Most cars have a rev limiter built in and will not let the engine goe past 4000 rpm's you may want to change out the spark plugs as often if it has flooded just once the plugs do foul out

sounds like 'flaring' of the auto, maybe a service at the auto shop will fix it.

I would guestimate that your throttle position sensor is going bad. Or vac line. Hard to say with out vehicle info

Check the spark plugs are the exact recommended specification.
I have just replaced the plugs and coils on my 1996 Jag, and when I accelerated hard, the engine would shut off at 4000 revs, the engine check light would com on briefly and the tacho would jump about. Long story short, the recommended plugs were (NGK) BCPR6ES ( R for resistance), I put in BCP6ES (no resistance). When I put the old plugs back in, it was back to normal, when I stepped on kittys tail, it got angry real fast all the way to red line! Resistance spark plugs were originally to suppress electrical interference on the radio, modern engines also need to suppress electrical interference to the engine management system.
http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqresistor.asp?mode=nml

Hello
The engine and transmission in this cars drive train are fully electronically controlled by a computer called the PCM (Power Train Control Module). Whenever a problem like this occurs the computer stores a record of the problem (there are of course some exceptions to this, like the fuel pump, engine coolant temperature sensor and MAF sensor for instance) in the form of a fault code in its memory, to read these fault codes you must have the systems memory scanned with a special tool. Once the fault code(s) are read you then must perform the appropriate diagnostic testing to find and resolve the problem(s) DO NOT REPLACE ANY PARTS UNTIL A TRAINED TECHNICAIN HAS DIAGNOSED THE PROBLEM TO AVOID SPEDING YOUR HARD EARNED MONEY ON PARTS THAT MAY NOT CORRECT THE PROBLEM

Neutral or Drive N rev limiter to prevent engine damage from no load over acceleration. D: many things could be at fault. Has your fuel filter been changed in the last 30,000miles. What about a tune up? Is your CEL(Check Engine Light) on? If so have a parts store check for codes, some do it for free. Then get back to us and we can go from there.

To begin with, if you are revving a cold engine to 6000 RPM, you are asking for a blown engine. Most OBD vehicles are equipped with a rev limiter that will cut off fuel at 3000 to 4000 rpm to prevent you from over-revving your engine and blowing it up. If yours is revving to 6000 RPM cold, then the rev limiter, for some reason is not working while it is cold. I have no explaination for this. The best thing I can tell you is to stop revving your engine so high when it is cold unless you really want to see what an engine looks like after is has gone off like a grenade.

take it to a mechanic to check the timing. if the timing is off then it may run at a idle an a little above but once you rev it up then the timing will truely show an it will run like ****. have you checked your air filter that may be another cause. hope this helps

The rev counter could be faulty.
I hope the engine is responding ok on accelaration inspite of the rev counter being stuck on 3000rpm , if so thn its definately the rev counter being faulty.