MM951

Just went out for a glorious cruise in my 951. It feels great to finally be able to drive it and it is certainly a whole different world compared to the N/As

and I love my suspension. Bumps are decent amount more pronounced but its tolerable. Now I just have to corner balance and align it and I'll see how it really is

Only problem I seem to be having at this point is the car seems to hit a brick wall ~8-10psi (pretty much any decent amount of throttle at all above 3.3kish rpms) spark plugs are new, wires are recent and ohm out, and A/Fs are in the low 12s when this happens.

Any ideas?

87 944 C

what do you mean brick wall? like the pressure doesn't hit 11, or it doesn't want to accelerate?

if you're new to turbo'd cars, the higher gears(probably 4th and 5th for a 951) won't even come close to putting you in your seat with the turbo. go down a local road and go into 2nd gear, and bring it up to, 5800rpm(or so). you'll kill gas, but you're gages should read full pressure, a/f(if you have a gauge) will be proper.

lastly, you could have a boost leak

Darwantae951

He's not new to turbo cars, are ya Mike?

What he's saying is that when he hits ~8-10psi he experiences pretty much total power loss.

And my car will put me back in the seat in 4th.

MM951

Yes I am a total turbo noob

I think my car should put me back in the seat in 4th gear with a MAF and 60-1 Hifi..

and Darwin is right, I experience total power loss. I messed around with it today some and have some mre info to add

I turned the boost up from 10lbs to 13-14ish and now for about 20-30 minutes after starting it I can floor it in 1st, 2nd, 3rd . My A/Fs are where they should be and the car is up to temp. Then after about 30min it hesitates again at the same 8-10lbs and 3.3K+ rpms. New temp sensors/harnesses/ etc. My WB02 is also showing a lean condition after 30minutes (when the problem starts)

SamGrant951

Id want to know what the fuel pressure is doing before/after it does the wierd running.

Rock

Brick wall? Youre hitting the knock protection, aka "overboost" or "boost cut" sir.

Lean condition= Knock= The overboost.

Its a safety every 944 has except the 2.5l N/a. Try running 93 if youre not, also check for vacuum leaks around the engine.

Techno Duck

Glad to hear you can finally enjoy the car Mike. Im going to start putting my 60-1 in during the next few weeks. I havent drove my car in about a week now and already miss it.

mclarenno9

What he said. Could be a dying/weak fuel pump. When it gets hot it doesn't work properly and once the engine is under any decent amount of load it isn't supplying enough fuel. Can you run at slight/partial throttle above 3300 rpm?

F18Rep

Yea Mike ya damn newbie. If you'ld ever spend a few minutes wrenchin on that thing ya might learn something....;] Bruce

MM951

Jon, you will love the 60-1. It is so good. I just wish I had a vitesse MAF like you

rock, good suggestions.. I always use 93 and I tried finding a leak with propane and couldn't find anything. When warm I have about 18" at idle (slightly down from 20" when the engine was brand brand new)

sam and mcclaren09, good thinking. I can go up to about 5ishK with partial throttle. Think if the fuel pump was acting up as it warmed up it would also cause me to run leaner throughout all rpms after ~30 minutes?


thanks

adrial

Glad to read you finally got the car running.

Another vote for checking fuel pressure when it starts giving you problems...

Full boost @ 3500rpm vs. partial throttle (0psi gauge) at 5k rpm would probably get you pretty similar fuel flow requirements...and thus a problem at 3500rpm and full boost should be a problem at 5k and 0psi gauge.

The difference is that at 3500 rpm and full throttle you are in open loop, whereas 5000rpm and 0psi gauge you are in closed loop. So any issue that exists (if relatively minor) will be covered up by fueling corrections. A relatively minor issue at part throttle may turn into a bigger issue at wide open.

Still, I think it'd be weird for a fuel pump to mechanically be weak but perhaps it's a ground issue? Easy to check by measuring voltage at the fuel pump.

EDITED to correct open loop vs. closed loop typo.

Van

Glad to hear you're enjoying the car Mike. I guess that means you're not going to sell it to me to part out?

Can you take a video of the tach/boost gauge as you accelerate so we can see and hear your problem?

If you're free some time, swing by and take me for a ride. Let's also plan on a time for corner balancing your car.

porshhhh951

Interesting.

Keithr726

You have maxx chips right? Now by loosing power, do you mean the car stumbles? I had a problem where I'd go full throttle, the car would accelerate then stumble then suddenly start accelerating again. After replacing the tps and installing a new wastegate and mbc that problem is long gone.