boxster 986 problem ,any ideas
 

ive recently bought myself a 1999 boxster 986.when i bought the car i test drove it and everything was fine i handed the money over and away i went on the 3 hour journey home as soon as i got to the first bit of open road i opened it up heard the lovely sound come out of the engine shifted in to second gear then bang it cut out on me i pulled over started it up again and gently drove it home chugging and banging most of the way home.the next day it started up perfect i went up the road in it but as soon as i put the engine under presure it cut out and started popping and banging again.so i took it home and changed all the plugs and this has improved it but its still not right cos instead of it dying on me at 3000 revs it now revs to 5000 which it struggles to get to then it feels like a rev limiter has cut in at 5000 and wont go any further but it doesnt cut out it just wont go past 5000 and its really flat and has no power.ive put a brand new set of 6 coils on it and still its no better ive had it plugged in to my friends computer and its showing no faults what so ever.could it be the air flow meter.ive even unpluged the air flow meter and it still runs exactly the same and does not throw the light up on the dash.from cold its very jerky and horrible to drive till it gets warm,it idles fine it doesnt cut out at traffic lights or anything like that its just very flat,slow and wont go over 5000 revs and im hoping you good people can help me out with what it might be.thanks grant.

Well that sucks, it's not suppose to act up like that on the first day of ownership, it usually waits until the second day and beyond :D

"air flow meter" <- what is that? :confused:

Sounds like a mass air flow sensor (MAF) problem, at least a good place to start, many posts on this forum and others, good luck!

It sounds like you may have a fuel delivery related problem. You might want to consider changing the fuel filter or fuel pump. More unlikely, you might just have old/bad gas that's just not igniting under higher pressures (loads). The car's probably got to go to a mechanic to know for sure.

The first thing I would have done is take it back to the seller and inquired whether this was a problem that was existing at the time of purchase and not disclosed. If you had driven it around for a week or two before the problem that is one thing but if on the first stretch of road after driving off the lot it acts up I would be highly suspect. How did it drive when you test drove it before the purchase?

It could be a number of things causing the problem. If you are new to the vehicle I would take it in to a shop familiar with these cars for a diagnostic.

You can check if it is the MAF by disconnecting the MAF and driving it while diconnected. You won't hurt the car. If it takes care of the problem, clean it and or replace the MAF.

In this case guys, it's probably not the MAF.

Hi grantmac1, sorry to hear about your sad situation. Hope you didn't suffer too much buyer's remorse like me. Did you find a cure for the irregular running engine? I seem to be having a similar problem (among a few others) and have seen many different threads with potential solutions. The list so far includes:
1. MAF gone bad
2. Secondary Air Pump gone bad
3. Vacuum Leaks at intake
4. Bad gas
The list goes on and I don't know where to start. If you found a cure, please share...Cheers!