1996 S40 2.0 loses power during acceleration the first 20km

[thaje]

The following experience is a Volvo S40 2.0 1996 250,000 km (Motor Control: Fenix 2.1 with ThrottlePositionSensor / TPS).

It starts willingly in the day's first start, and with the slightly higher revolutions to idle during the first minute. I step on the accelerator to accelerate - it can not take the gas (the losing steam / power, acceleration absent and groans, but come anyway under any stuttering up to speed) as if it does not get enough fuel in neg. to throttle opening. It is more marked by revolutions less then 3000. After about 20 km, the phenomenon is over and it accelerates without hesitation (after the first 5 km thermometer shows that the engine is warm).

Has discussed the issue last year in August and September - but had removed it at the time of changing the spark plugs.
The problem - as described - is unfortunately returned after about 8 months of good behavior:
http://www.volvosnak.dk/phpbb3/viewtopi ... =3&t=11165

Someone who can make a diagnosis?
Anyone with similar experience - and possible. remedy?

Vh Thorkil

[thaje]

Here are my experiences after an advice to test the temperature of the cooling water (NTC) and how it affects motor control.

Component information from the description:
- 25 C - 2 KOhm (6 KOhm)
- 80 C - 300 Ohm
Interruption of the connection between the sensor and the ECU is equivalent to strong resistance at ECU entrance - which corresponds to cold temperature.

Measured values of the Volvo:
- Warm after driving (after 15 min rest): 490 Ohm
- Cooled after about 2 hours: 1,800 Ohm

Experiences at engine start and sensor connected / disconnected:
1) Without sensor: The engine hard to start (as previously seen). The engine came, however, started after a few turns, but could hardly take the gas when I stepped on the accelerator.
2) With the sensor (1800 Ohm): The engine started immediately and there was full thrust (acceleration).
3) Reiterated interruption of the sensor: Could not start the engine (2 trials where the starter was eagerly).
4) The sensor is connected again: The engine started willingly and the acceleration ok!

Conclusion:
Acceleration and starting the engine is dependent on the engine temperature.
Check 1) showed that without sensor (ECU think it's hot engine) and cold engine (which requires chokervirkning - extra fuel), so the engine could hardly or not started.
It seems to point to a possible defect in the temperature sensor characteristic (which can tease motor control).

Seems troubleshooting to be on the right track?

[sbattaglia]

I have a 2002 v40. I had this problem, accompanied with a check engine light. From a complete stop i would pump the gas until it would hit 15-20 rpms then it would finally start moving. Check engine code was a generic P600, which no one knew what it was. Spent 170 at the dealer. Answer a person who claimed to be a mechanic, was checking my fuses in the engine and pulled out a fuse and put in back in the wrong place. Problem solved. Cleaned cylinders which is what on line came up with, but that wasn't the issue.