rpm limited to 2500revs

[RBAustralia]

Hi Everyone,
My first post.

I have had a 318is Dec1994 manual Black on Black since 2008

Not a single problem since then, until I couldn't drive it for a year.

Now its been 6 months back on the road and for the last 2 months it will not accelerate more than 2500rpm.
This guy had the exact problem I have http://m.youtube.com/watch?v=mCiZsgAE4gk

When all this started, it could rev to the limiter when cold but after 3 minutes it reduced to 3250rpm.
Now it goes to 3000rpm when cold and reduces to 2400rpm later.

So far I have replaced the...
Fuel pump
Fuel filter
Spark plugs
Air Flow Meter
Coil Pack
Fuel Injectors
Air Filter
Engine oil

I have read the resistance of the
Cam position sensor: 1400 ohms
Crank position sensor: 540 ohms
I still doubt the sensors though.

I even disconnected the exhaust from the manifold incase there was a broken baffle in the catalytic converter.
It raining right now but as soon as it clears I will clean the ICV.

If anybody can direct me in the right direction, it will be greatly appreciated.

I'm from Sydney Australia 21yo totally confused.

[deansweet]

Have you double-triple checked all your vacuum lines?
If you still have the 'mess under the intake' still there? check those as they tend to split at just about every vacumm line end.

[doitover]

One oddball thing, if you happened to put the AFM on backwards, it will do that.
Is it making any noise or blowing smoke? Have you checked the compression?

[colin86325]

Also check the Throttle Position Sensor.

[RBAustralia]

Update. Worked on the car today....

Swapped the throttle position sensor with another one that was working fine. No change what so ever.
 
Swapped the ecu with one wat was totally fine and the same part number.  No change what so ever.

Wanted to swap the icv but that does nothing when revs are at 2500rpm anyway, surely can't make a difference.

The AMF is on the right way. I've only ever taken it out with the filter cover together.

[DesktopDave]

Sorry to hear about your troubles...but welcome to the club! Please stop throwing parts at the problem, that gets frustrating and expensive.

Your car runs better on cold-start and falls on its face once it's warmed up and running closed loop. So I'd check the closed-loop sensors. The coolant temp sensor, intake air temp sensor, O2 sensor (if installed). You might have knock sensors too. Don't forget the main, fuel and O2 relays, they can get sick or dead and really impact performance.

I'd also be interested to see if the crank sensor is clean and close enough to the flywheel...should be very close - less than 1mm. Also check the jacket wires - terminal pairs 1&3 and 2&3 must have very high resistance...something like 100K ohms.

I know you replaced the fuel pump & filter...but did you test fuel pressure at or before the rail? The proper test is to tee off a pressure gauge and measure LPH...but a quick and sloppy test is to dead-head the pump by plugging the gauge right into the supply hose. A healthy pump should be able to push 80psi (for short periods of time).

If you go through all that pain and still haven't tracked it down, pull the cover off the DME and check the four coil drivers. I've seen three 175 DMEs that cooked one. They'll look obviously burned up. One of these days I'll post a DIY repair guide. I have a junk E36 EWS DME that's going to donate spare transistors to rebuild the 175 units.

This is an excellent post, I've used this same troubleshooting plan and philosophy to troubleshoot my cars (your post inspired me to look for it, I'd like to thank you):
http://forums.bimmerforums.com/forum/showthread.php?1690962-Ever-wonder-what-all-those-sensors-actually-do
 

[SkidMark]

Stomp test? Codes? I would assume it has to be throwing a code if not several... just my two cents....Skid

[RBAustralia]

Finally got mechanic to run a scan.
He wrote down code #68 and said it means the PCV Valve is faulty.

I tried the stomp test many times. Didn't work, mayby my car doesn't have that feature.  Doesn't have a check engine light either.

In theory it makes sense that the pressure in the intake increases beyond the crankcase pressure, causing air to flow the wrong way, because the PCV didn't close.

I wonder if I can just clean it up and see an immediate change. Will try 1st thing in the morning and update results.

[Tgoode318]

Hmm.. when my pcv went bad the idle would fluctuate wildly and the car lacked power. Also it was throwing the trouble code "1222" Indicating a rich/lean condition the computer was unable to adjust for. With mine if you listened carefully near the pcv valve you could actually hear it making a "phising" noise which is abnormal. This noise is what clued me into the fact that it was bad in the first place and sure enough upon replacement & cleaning of my icv (which was also installed backwards) The 1222 code was fixed and the engine ran properly.

[RBAustralia]

Apon evaluation of the PCV valve. I doubt its faulty. The code #68 refers to the knocksensor2 so again it's nothing to do with the PCV. I've taken the initiative to get myself a Knock/ping sensor. Part number 12141734580 which got superseded by part number 12141739368.
 Will replace it over the weekend and give an update.

[Tgoode318]

I have never heard of a code #68 on a E36. It may have something to do with where you are located/rhd etc..
I have had a knock sensor's go bad recently and it threw the code "1226". When it was on it didn't cause any drive ability issue's, especially nothing like you mentioned above.     

This is a list of all e36 codes for North American E36 LHD .. 
1211      DME Control Unit 
1215      Air Mass Sensor
1216      Throttle Potentiometer
1218      Output Stage, Group 1
1219      Output Stage, Group 2
1221      Oxygen Sensor 1
1212      Oxygen Sensor 2
1222      Lambda Control 1
1213      Lambda Control 2
1223      Coolant Temperature Sensor
1224      Intake Air Temperature Sensor
1225      Knock Sensor 1
1226      Knock Sensor 2
1227      Knock Sensor 3
1228      Knock Sensor 4
1231      Battery Voltage/DME Main Relay
1232      Throttle Idle Switch
1233      Throttle Wide Open Throttle Switch
1234      Speedometer A Signal
1237      A/C Compressor Cut Off
1242      A/C Compressor
1243      Crankshaft Pulse Sensor
1244      Camshaft Sensor
1245      Intervention AEGS
1247      Ignition Secondary Monitor
1251      Fuel Injector 1 (or group 1)
1252      Fuel Injector 2 (or group 2)
1253      Fuel Injector 3
1254      Fuel Injector 4
1255      Fuel Injector 5
1256      Fuel Injector 6
1257      Fuel Injector 7
1258      Fuel Injector 8
1261      Fuel Pump Relay Control
1262      Idle Speed Actuator
1263      Purge Valve
1264      EGO Heater
1265      Fault Lamp (check engine light)
1266      VANOS
1267      Air Pump Relay Control
1271      Ignition Coil 1
1272      Ignition Coil 2
1273      Ignition Coil 3
1274      Ignition Coil 4
1275      Ignition Coil 5
1276      Ignition Coil 6
1277      Ignition Coil 7
1278      Ignition Coil 8
1281      Control Unit Memory Supply
1282      Fault Code Memory
1283      Fuel Injector Output Stage
1286      Knock Control Test Pulse
1444      No Fault Codes

[RBAustralia]

Just finished installing the new Knock Sensor. It didn't do anything.

The plastic around both the old ones is falling off but they must be still working.

Going to get the fault code cleared and then scanned again tomorrow.

Also got a PCV valve. Will swap it over tomorrow just to rule it out as a possible cause.

[Tgoode318]

Hopefully its the pcv valve! Gl

[Tgoode318]

so i was leaning toward some type of sensor problem but here is an interesting thread i found while searching for your problem because you have me interested!
This person describes almost the same thing you were talking about and its on an m44 engine.
the first thing he did was replace his pcv to no effect.  At the end he finally figures it out the baffle to his cat converter was broken and his cat moved into a postion in which it blocked the exhaust gasses.
Probably not your problem but worth taking a look at!
http://www.bimmerwerkz.com/forum/3-series-e36/3k-rev-problem-e36-m44-engine-60103.html

[keflaman]

A vacuum gauge could tell you whether the cat is blocked or not.

http://autospeed.com/cms/A_2393/article.html

http://www.classic-car-magazine.co.uk/articles/fault-diagnostics-vacuum-gauge.html