hi guys!!

[vwmiker]

just a couple questions? can you guys tell me if an exhaust manifold leak would have impact on car other than noise?
would a bad o2 sensor have effect?

my car is a 924 turbo, and the car starts fine most of the time. but it is difficult to rev. However is I pull the air filter housing off and manually push the air meter (the fuel distrubuter etc) flap in as rpms rise the car sounds great, but if i do not manually do this........just doesnt want to go. This is my second fuel distrubuter and air meter? same thing with both!! so it must be something else?

thanks

mike

[fast924S]

That is kinda weird, It will rev fine is you move the flap your self??? Is your air box blocked????

[vwmiker]

no blocks as i can see, i had the fuel distrubuter apart, and the ai meter box, cleaned it made sure it worked and re-installed it, and still same problem. What actually controls the flap? is it vacuum? I replaced the vacuum lines all underhhod sensors except one and im not sure what it is called. But the car does have a manifold leak. I dumped the fuel, flushed the tank.????????? ahhhh i dont know. i ordered a compression tester, will check.

[fast924S]

Well IF the car has a manifold leak that could be causing some problems with the turbo and boosts levels and screwing up the A/F ratio

[vwmiker]

so manifold leak can cause running problems? do you have to pull motor to change manifold, looks pretty tight?

[fast924S]

Depending on how big the leak is. Since it is a trubo I would say it is causng some problems. Im not sure if YOu need to pull the motor since I have not worked on a 924T Im sure more will post later

[vwmiker]

i keep reading MSDS headers............but cant seem to find one for the turbo 924. Will the non turbo fit a turbo?

thanks

[fast924S]

No MSDS does not make a header for the 924T or the 944T only NA's and no the NA header will not fit you turbo

[vwmiker]

do you know who does make the header for the turbo?

[Britwrench]

The first thing to do before just guessing is to do an accurate diagnosis and find out exactly what is wrong. You will need the correct workshop manual (get the Haynes 924 one and the official Porsche Turbo supplement) and check everything. These cars have a few and curable faults but not until you know what the problem is.

No-one nowadays as far as I know or heard of makes a manifold. Problem is that repairing the usual problems with 924T exhaust systems ends up close to what the car is worth if a shop is doing it. The existing manifold, if it's leaking can be repaired. You must replace the exhaust studs in the head as they snap and all the o-rings or gaskets (depends on year) and probably the turbo oil drain hose.

[vwmiker]

i have the haynes manual. i have read it over and over and just cant figure outthe problem. i am planning to pull the e manifold off so Ill know more after that!! thanks just thought someone might have had the same problem

mike i will keep it posted, but please continue to offer suggestions

[Britwrench]

So if that isn't the fault then what are you going to do? Have to diagnose and locate the problem first.

Exhaust manifold unlikely to cause this fault as it's intermittent. Unless your cat has come loose and is occaisionally blocking the exhaust system. Lack of power could be a fuel related problem so what is the fuel pressure? What do the spark plugs look like?

With lots of previous experience, the last thing on a 924T I would ever do is remove the manifold. Price up the parts you WILL need to put it back together so nothing falls off after a while before starting the job.

[vwmiker]

plugs wires are new - cap rotor look great. fuel filter will be replaced soon, fuel pump works. o2 sensor also being replaced. so i will not remove anything untill then. I am also olaning to check fuel pressure and fuel amounts at pump and injectors. i will report back when this is done. I have a spare stock e manifold that does not leak as i have a parts car - am am planning to change to e manifold and down pipes as the o2 sensor threads are no longer!! How can i check the cat?

thanks

[Britwrench]

You could probably live without an 02 sensor or just get a pre-made threaded socket, available easily and get that welded in.
To check the cat just use a temperature checking tool, the front should be a different temp to the rear. Or just unbolt the front and run the engine..not drive it. Make sure you have someone there checking if you do that.

[vwmiker]

ok thanks i will check the cat

[fast924S]

If it was the cat then why would it rrev fine when he moves the flap by hand???

[rb101]

Originally posted by vwmiker
What actually controls the flap? is it vacuum?

The engines air requirment pulls the flap down, increasing the fuel flow thru the fuel distributor. Check all the intake hoses for cracks and leaks. One leak will throw the whole CIS system off.

[vwmiker]

cis, thanks ill check the fuel pressure and flow. I have replaced all vacuum lines. thanks