Engine problems

[Guest]

I haven't been using the 944 enough, last time I drove it to work (15 miles fast dual carriageway) it ran fine but on return at about 60-70 mph I accelerated and discovered that I had lost all power - more precisely all power to accelerate - speed/revs were not lost.
I pulled over and looked for anything obvious - loose pipes etc. Not seeing anything I restarted and drove home with the usual acceleration up to 2nd gear/60mph but the same upper end loss of acceleration. Turbo appears to be kicking -in at higher revs.

Since then a test drive has revealed the same problem.

It's booked-in with Paragon next week but meanwhile any ideas???

Cliff.

 

[Guest]

Weird. So you can get up to 70ish but then nothing, yeah?
Up to 70, does it accellerate the same? Does it feel normal and then you hit a brick wall? Or does it struggle all the way?

It sounds a problem with your turbo but it's a bit hard to diagnose a specific problem from behind a keyboard. Check your airbox/filter, make sure it's not clogged. If you've got a Haynes, have a look through it, it might help.
Apart from that all i can offer is good luck. But i'd defo suspect the turbo.

 

[Fen]

When you say "turbo appears to be kicking in at high revs" what do you base that on? I suspect it's a leak; split pipe to the intercooler perhaps. In the lower gears the boost event is quick enough that the leak doesn't seem so apparent, in higher gears where boost lasts longer and gets higher it's parting the split and leaking yor boost away and running rich because of it. Mike had exactly that happen on his unique green Turbo - were they the symptoms, Mike?

 

[Indi9xx]

If it idles ok, I would suspect you have one of the following problems.

Blocked fuel filter restricting flow at higher demand levels
Split intake boot opening up under boost, but closed off boost.
Failing ignition components breaking down under load (higher cylinder pressures)

I did see a similar problem to this where the throttle position switch had gone up the shoot.

My advice would be to change the fuel filter first if you have not had it changed recently.
Then to take off all the intake rubber boots and carefully stretch them about looking for a split
Then the check the ignition components are all within spec (coil resistance, check plugs, examine plug leads, distributor cap and arm)

If all else fails, you may have to resort to getting a pro to look at it ( But this is a hard one to diag without having the car in front of me.

 

[berg944]

Mike had exactly that happen on his unique green Turbo - were they the symptoms, Mike?

Not really, When one of the inter cooler pipes started to leak it was running OK until the knock sensor trigged 'safe mode' under heavy boost.

When the pipe completely came off the engine would not idle (probably too weak). It then seemed to over fuel when the turbo came in and triggered 'safe mode' again. It seemed normal cruising between 2-3K rpm.

Sounds like fuel starvation although I have had a similar problem with a motorcycle and that was a wet air filter.

Mike[:'(]

 

[Guest]

Thanks for all your replies - the turbo leak theory has the right feel - I will investigate as per your suggestions and report back for the record when diagnosed .

 

[Guest]

How wrong was I...Took the 944 to Paragon last week - only just made it there - approx. 20 miles slowish roads. About 3 miles away the revs fell away and all response to the throttle was lost - dropped down into second and crawled along at 20-30mph.At some points having to stop and then pull away again just getting up to say 30-40mph and 3rd gear only soon having to drop to lower gear and slip the clutch to maintain any forward momentum.
After a service, MOT (expensive front shocks) I received the car back with a loose distributor cap blamed as the fault. The car was road tested for 10 min.and ran without problem.
As I drove it home the car ran fine until fault re-appeared about 15 miles down the road []- initially as a fall-off in power then a misfire then carried on normal running - however by the time I made it home I was crawling along again, apparently on two cylinders.
Monday morning the car made it from the garage to the road then lost all will to move. An hour later it re-started and drove without problem the 10 miles to my nearest Porsche centre where it now resides (I couldn't face the longer drive/risk of breakdown to Paragon).
An hour after delivery I was telephoned and told that the fault was temperature sensor no.2. The part will be fitted today.

I live in hope[8|]

 

[DivineE]

Slightly off topic but... Are you refering to Paragon in Northampton? If so they are fantastic chaps I just got my car back from them today.

p.s. My guess would still be something in the ignition because I had a very similar experience shortly after I bought my first turbo but this was cured with a new rotor arm and dizzy cap. The car did exactly as you say run fine for 15-30mins at a time then lost power forcing me to go down through the gears because the engine was bearly running on one cylinder then after I'd backed off for a bit I seemed to fire more cylinders again.

Hope you find the fault and cure

 

[sawood12]

I've just replaced my dizzy cap, rotor arm and HT leads this weekend. Boy did it need it, the HT leads looked OK but the insulation was so perished it crumbled when I removed them. As a result the car is now running much more smoothly and idle is rock solid - I recommend this to anyone who hasn't already done it. It's fairly cheap and easy - although access to the dizzy cap fixing at the 6 o'clock position was a real pain in the backside to get at due to the intercooler pipe and the pop-up light mechanism being right in the way. I'm surprised at Porsche - couldn't they have rotated the cap by 90 degs so the fixings were at 9 and 3 o'clock where access would be easy??

 

[Hilux]

An hour after delivery I was telephoned and told that the fault was temperature sensor no.2.

I assume that this is what the engine management system uses as against the temp gauge sender?

 

[Guest]

Paragon - Five Ashes, Sussex.

Replaced the leads, cap, rotor arm, plugs a few months ago - the problem occured since then.

 

[Guest]

Porsche now say not temp sender no.2. Are re-fitting the AFM to see if MAF at fault.[&o]

 

[Big Dave]

We had almost the same problems with a "Nissan 200SX "that we owned...
It would drive great until it was "pushed harder".

We eventually found it to have a cracked intercooler . It was fine at low boost levels BUT when the boost increased the intercooler "crack opened up "+ let all the boost flow out into the atmosphere, causing a missfire + very rough running....

Hope you get it fixed Ok...+ not too much £££££££££££££££

 

[Fen]

I had something sort of similar on my Turbo after a service. It turned out the indy (not my current one, though it was an honest mistake and wouldn't have stopped me using them again) had kinked the fuel line while replacing the filter.

 

[macandsue]

HI Clifford
Just a thought, when you had your leads done did you ever open lid and watch for shorts from coil to dis.lead it can if carelessly fitted wear out on light lifting gear slowly at first then your symptoms occur.Open lid in dark rev to 3000 and watch for sparks.Just a thought though