TD5 Stall Test - Low Power

**gazk** · 2nd June 2012, 08:14 PM

Doing a Stall Test on a 2001 TD5 Auto in a vehicle that I am dismantling.
The manual indicates that you should get 2600 to 2800 rev/min on a diesel.
I'm getting 2100 rev/min maximum !!

The manual says "A reading between 1300 and 2600 rev/min (Diesel)
indicates reduced engine power."
I've checked the MAF with the NANOCOM readings are OK, changed the MAF for a known good one - same result.
There are no engine faults reported on the NANOCOM.
It has oil in the injector harness which I have cleaned up and am flushing through with contact cleaner and metho. It revs quite smoothly and freely in neutral and sounds good

The vehicle has only done 149000km, it has a Sequent II gas injection system, a TRS chipped ECU, an aftermarket (large) intercooler, the EGR has been removed and it has a 3" exhaust system.

Any suggestions where I should look next?

Update : Checked the Wastegate actuator (replaced with a known good one) and replaced the Ambient Air Pressure sensor with a known good one - still gives around 2100RPM. The wiring at the red plug on the ECH appears to have been modified - probably something to do with the Gas Injection system - will check that out next.

**northiam** · 3rd June 2012, 08:19 AM

Gary did you get another wreck to dismantle???

Sounds like it could be the wastegate not opening.

Regards
Glenn

**gazk** · 3rd June 2012, 09:10 AM

Hi Glenn, Yes it had a few good bits I was after. I'll pull it apart gradually and sell off what I don't need. If I can get it running properly I will keep the engine and sell the other engine with the new head from the car we pulled apart a few months back.

The turbo was my next thought, it drove well up to about 30Km/hr in the limited space I had to test drive it.

I'll check out the wastegate when the rain stops.
Cheers

**northiam** · 3rd June 2012, 09:15 AM

EU -3 engine this time?

**gazk** · 3rd June 2012, 09:23 AM

EU-2, but I'll keep it and all its accessories for now, it even had a brand new alternator fitted. Might look for a TD5 Defender with a blown engine

**gazk** · 8th June 2012, 06:27 PM

Eventually found the problem

it was a neatly cut wire at the red plug on the Engine ECU. The wire in question goes to The Manifold Absolute Pressure (MAP) sensor on the inlet manifold. (Not to be confused with the MAF sensor.)
The same sensor also does the inlet air temperature (IAT)

If you still have the EGR fitted this sensor can get totally gummed up with tar.

The manual states that Power is restricted if the MAP sensor fails. I had already changed the sensor but that didn't fix the problem - I now know why !

**Gaudough** · 8th June 2012, 06:35 PM

Originally Posted by gazk

Eventually found the problem

it was a neatly cut wire at the red plug on the Engine ECU. The wire in question goes to The Manifold Absolute Pressure (MAP) sensor on the inlet manifold. (Not to be confused with the MAF sensor.)
The same sensor also does the inlet air temperature (IAT)

If you still have the EGR fitted this sensor can get totally gummed up with tar.

The manual states that Power is restricted if the MAP sensor fails. I had already changed the sensor but that didn't fix the problem - I now know why !

So did Nanocom show no Manifold pressure?

Regards Gordo

**gazk** · 8th June 2012, 07:22 PM

Pretty sure it did - possibly the default value. I know the IAT was working. I'll recreate the problem tomorrow and check the readings - I will let you know the result.

The workshop manual (18-1-13) states:
The MAP/IAT sensor can fail the following ways or supply incorrect signal:
Sensor open circuit.
Short circuit to vehicle supply.
Short circuit to vehicle earth.
Contaminated sensor element.
Damaged sensor element.
Resistance in wiring harness.

In the event of a MAP/IAT sensor signal failure any of the following symptoms may be observed:
If the MAP sensor fails manifold pressure is set to a predetermined default value and the engine performance will be reduced.

If the IAT fails the ECM will set air temperature to a fixed value. The MIL will not illuminate in a MAP/IAT sensor failure and the ECM will use a fixed default value from its memory.

Update: with the MAP/IAT sensor open circuited the Nanocom shows the ECU's fixed value defaults as 100Kpa and 120C.

**bob10** · 9th June 2012, 07:41 AM

Please excuse my ignorance, but what exactly is a stall test? [ probably something obvious, but I'm only on my first coffee] Bob

**gazk** · 9th June 2012, 08:46 AM

D2 Automatic Transmission Test:

From the workshop manual: Stall Testing

1. Chock the wheels and fully apply the
handbrake.
2. Start the engine and run it until it reaches
normal operating temperature.
3. Apply the footbrake and select 'D'.
4. Fully depress the accelerator pedal and note
the tachometer reading. The figures should be
as given below. Do not carry out stall test for
longer than 10 seconds, and DO NOT repeat
until 30 minutes have elapsed.
l V8: 2200 to 2400 rev/min
l Diesel: 2600 to 2800 rev/min
5. A reading below 1300 rev/min indicates a
torque converter fault, ie stator free-wheel.
6. A reading between 1300 and 2200 rev/min (V8)
or between 1300 and 2600 rev/min (Diesel)
indicates reduced engine power.
7. A reading above 2400 rev/min (V8) or above
2800 rev/min (Diesel) indicates clutch slip.
NOTE: The figures quoted above were
measured at sea level with an ambient
temperature of 20°C (68°F). At higher altitudes
or higher ambient temperatures, these figures
will be reduced.

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