911 3.2 engine runs, but when driving gets the hickups...

[usm911carrera]

Could somebody tell me, whats could be wrong with the engine or electrical system(s)? It runs fine, when not driven. When driving and engine needs to give more power. Engine.. after a little while gets the hickups. I have checked the fuelpump, replaced the fuel-filter and fuelhoses/lines with new ones.

Could the fault be in: the ignitionsystem? sparkplugs and wires?
The fuelrelay DME underneath driverseat?or what??? The engine runs well, but won't give me power and drops dead. On higher rpm, when warm & driving over a bump or true a hole in the road.

The engine stops..... but will start again after 2-3 min. no power 4 high rpm. Give me the feeling that fuel or ignition or power was cutoff...

Yo Dudes ..please Help me Out !!!!

[catuck]

Check for vacuum leaks, check DME relay, check your ignition wires for breaks - run engine in dark and look for sparks.

[marcesq]

Check your distributor cap and rotor. If your cap is old it could have developed cracks that only cause problems when the cap heats up and the cracks expand. This causes bad contact between rotor and plug wires pickups and missing.

Unplug your O2 sensor if you have one and see what happens.

Check to make sure the 3 sensor connectors beneath the blower motor are tight.

[usm911carrera]

Originally posted by marcesq
Check your distributor cap and rotor. If your cap is old it could have developed cracks that only cause problems when the cap heats up and the cracks expand. This causes bad contact between rotor and plug wires pickups and missing.

Unplug your O2 sensor if you have one and see what happens.

Check to make sure the 3 sensor connectors beneath the blower motor are tight.

I will replace the cap & rotor tommorow, just incase. Because they look faulty and old. Then checkout the ignitionwires when its dark, if those have any sparks/leaks. then i will replace them 2.

I don't know if i have a O2 sensor(lamda) din't think so.

And about those 3 sensor connectors, beneath the blower motor:
they are tight and ferm. Someone told me the problem could also be; that the sensor connected to the white one, cause this strainge engine beheavior. what is the function of it?
Could it give a faulty reading???? and makes a mess of the engine/ignition management?

greetz & many thnx

[Jim Smolka]

Look for rust in bottom of the Dizzy. Clean if necessary
Check the adj of the speed reference sensor on top of the flywheel.

To determine if it is lack of power to the Fuel Pump, run a jumper wire from an always hot lead (red wire) at the front fuse block to the Fuel Pump fuse. This should cause the FP to run all the time. See if problem goes away...

[usm911carrera]

Yo Jim, thnx 4 the tip. I have cleaned the Dizzy..but still doesn't do the trick. when cold the car go's like a canonball. when warmed up .... it starts with little hickups, like some one pulls out the powercord.
Slitely degrease on gaspedal, there run of again... but not to mutch. Or als we get big... powercord plugouts.... so to speak. One occasion the gas went hewire, but only with clutch down. clutch up...engine goes dead.

I will try the Fuelpump trick later on....
If the problem is gone? conclusion is the BME relay faulty/defect? when it gets warm? and must be replaced....

Let me know Dude..

[Milu]

As it's fine when cold try checking out the threads on cht sensor.

[usm911carrera]

Originally posted by catuck
Check for vacuum leaks, check DME relay, check your ignition wires for breaks - run engine in dark and look for sparks.

ok thnx,
I will check these things out.
And see if the engines runs normal....

Thanks a lot..

[350HP930]

Check for loose and/or corroded connectors and relay sockets.

I have seen similar proplems on my own car and others due to nothing more than bad connections at connectors.

[stlrj]

It could be a bad head temperature sensor.

Joe

[usm911carrera]

Originally posted by 350HP930
Check for loose and/or corroded connectors and relay sockets.

I have seen similar proplems on my own car and others due to nothing more than bad connections at connectors.

Ok, i'm writing down all the comments.
And will investigate them all, i want to arease them from the possibillitys.

Thnx...Dude

[usm911carrera]

Originally posted by stlrj
It could be a bad head temperature sensor.

Joe

Thnx Joe...
One way or another we gonna solve the damned problem...

Thnx & 911 forever.

Greetz
Andrew

[stlrj]

If your head temp sensor is still the one wire type, then you might want to change it to the superceded two wire sensor to be safe.

Joe

[usm911carrera]

Joe,
if it is the CHT sensor i will replace it for the 2 wire type.
I have a lot of checkin' to do today.
And has to be dunn, one way or another.....
With the help of you all, i can do it the way it should't.
I'll get started....

Thnx

[usm911carrera]

Hello Guys,
check #1:
I have replaced the ignition rotor & dizzy... and tested the CHT-sensor with the resistormethod.

Motor runs great and gives me power.

check #2:
I have tested the CHT-sensor with the resistor-method:
no chages in engine behavior. starts good, runs smood & more rpm's. (i have i one wire type Sensor)

But when i let it run for a while, say: 15min.
While planning to drive away or pushing the gaspedal, with gears in neurtral. The motor rpm's runs up and down, from 900 up to 5000-6000 rpm like a Jojo. All by it self !
When ignition turned off, for a second...starting engine again.
Engine functions....normal again...?????????

check #3:
I have checked the Idle-positioner..works..i can hear it humming.
Looked into it, and see the metal "plate/something" go up and down slitely. "shaky effect...."
Is this good or bad.


question:
I geuss that Jojo effect (900-5/6000rpm's on the Idle, is coming from the Idle-positioner? I saw that "shaking effect" inside the housing.
Or is this normal. Or does this device,gets a signal from something else?