944 na low power

[kmakovac]

hello porsche world!
i have an 944 na and it goes well but have no enought power
it not accelerate strong,like the machine is hard to take RPMs

i take new spark,timing belts,the fuel presure is 2,3 when running and 3 when bypas the pump
the motor have 2-3 bar of pressure oil when ideling
injector works(but i dont clean it)
afm works great and is tested,no vacuum leak from enywhere,try 2 DME
all i do is the same

withaut o2 sensor the situation is harder,it loss more power

any ideas?thanks from kristian

[mattdavis11]

Timing.... Get it dead on and tighten the belt while it's cold, roll it around two times and check it again. It will most likely run the best for many different reasons when cold, one is timing- the absence of belt stretch when cold, two is fuel temp, and three is air intake temp.

I've noticed my performance slacking when the belts are loose. It runs like a gorilla with burnt nuts after a belt change/tension though.

What is the condition of the head? Any bent valves?

[911Rich]

Kovac, can you elaborate? What year is your car? 8 or 16 valve?
When you say it will not accelerate normally, does it miss as well, or is it just sluggish? Does it idle well or miss at idle? Does the exhaust smell rich? If your car has a cat, is it getting red hot?

[kmakovac]

my car is a 944 na 86 8v USA model,i put of the catalytic muffler(this is the first thing i do)
she is all original,about 95000 miles on it,i put of only the catalizator
it doesn't esitate to go but i don't feel the 150HP!
on idle the exaust color is gray but when you drive it is very black with smell(but i dont see fumes on exaust or black fumes
idle is perfect,new timing belts,sparks,fuel filters,presur of fuel on idle 2,3bar when i put of vacum from the regulator 3,1 bar
the sparks have a gray/redish colour on it every cilinder,trotle sensor tested,cold sensor os DME ok(kiloom is ok for temperature)

i only see that when you disconect the o2 sensor the car is slower,i feel that when is very hot or hot day situation is beter

i don't now what to do with this engine that it goes beter!

ANY HELP WANTED AND ANY IDEAS WELCOM! (i try all the things of clarc's garage,porsche manuals and lost of time...)

[ballysdad]

Is this car new to you? Has it ever driven any different? It is possible that what you are describing is normal for the NA and your expectations may be out of line with this car. There are a few performance mods you can do to get you off the line " a little quicker".. Before anyone gets into that tell us if this car is new to you and has it run better in the past.

[phoenix_iii]

Originally Posted by ballysdad

Is this car new to you? Has it ever driven any different? It is possible that what you are describing is normal for the NA and your expectations may be out of line with this car. There are a few performance mods you can do to get you off the line " a little quicker".. Before anyone gets into that tell us if this car is new to you and has it run better in the past.

"on idle the exaust color is gray but when you drive it is very black with smell(but i dont see fumes on exaust or black fumes"

Is not normal.

[kmakovac]

thank people
this car is new to me,but i have a 924 with 125hp and i think it goes beter,no at low RPM but on hight RPM is quicker and the 6000rpm arive fast in the first 3 gears,the 944 is slow in this,if you kick down on gas pedal in 2 or 3 gear on 2500-3000 rpm it acelerate(i think for a 150HP car) very poor

i have an 944 NA 84'with euro motor,i know she have 163hp but she goes superb,acelerate hard and take RPM quickly
the diference is not only this 15HP but more

i don't have documents for the euro 944 so if i don't resolve my USA i have to change the engine and maybe resolve my odisea with this car....i work on it a few mounths but nothing special change

[JivenJim]

I would do a compression test. Compression should be up around 150-155PSI on all 4. More than 15 PSI difference and piston rings or Valves are Bad. Bad valves, or piston rings will cause much lower power. Recheck timing of Belt position. Exhaust may have Catalitic converter that is restricted (partially closed). And would use electrical test on the Air Flow Meter sensor.
Dos Va Danya.

[Desert Fox]

Im having a bit of the same problem. MY car has been loosing grunt in the upper(3-6k) rpm range. I cant seem to figure out what it is. I have a feeling It might be a vaccum leak, but im not sure. I had a shop test the compression, and they said it was ok.

I know it can go faster. It did it this morning, almost snapped my head back, but this after noon, it jsut seemed to be sluggish again. the cat is not red hot, and I jsut changed oil and plugs.

The other day it was running rough, and I figured out I knocked the vacuum line that attaches right above the oil tester off.

I have no idea whats wrong. anywhere I should start?