Does xantia 99 auto 1.9L TD has a maf sensor?

wonderd · Post by **wonderd** » 08 Jul 2008, 21:54

if yes, where can i find it?

Post by **Peter.N.** » 09 Jul 2008, 09:38

If its an XUD engine, I don't think so, it only has basic electronic management - but I could be wrong - its happened before.

MikeT · Post by **MikeT** » 09 Jul 2008, 15:19

Mass Air Flow sensor is used to ensure proper Air-Fuel Ratio which is very important for petrol engines.

However, diesel engines don't care much about proper AFR and fitting a MAF would be overkill if not pointless IMO. Although, like Peter, I stand to be corrected as modern diesels get more complex by the day.

Would I be right in assuming you have a driveability problem and someone suggested the MAF to check? If you post more details I'm sure someone will find the solution for you.

Post by **CitroJim** » 09 Jul 2008, 16:35

The 1.9TD has no MAF sensor and as you say Mike, It could not make effective use of one. The 2.1TD has a MAP sensor on the intercooler and this is used to measure boost and is performs the same function precisely as the Boost compensation diaphragm (flying saucer) on top of the Bosch pump so strictly it's a boost sensor.

All 1.9TD engines determine fuelling mechanically. Only the timing is electronically controlled on the later models with the ECU.

The HDi engines do have a MAF sensor and this is their main method of determining the amount of fuel to inject.

wonderd · Post by **wonderd** » 09 Jul 2008, 17:19

Yes MikeT, you are correct; someone suggested to check the MAF but i didn't think i have one, just wanted to be sure.

My problem as i described in a different topic, is that the car doesn't feel like it supposed to, for example; when the turbo was not working, the car wouldn't pass 60km/h, and going uphills it would go down to 40km/h.
Second example; when the aircon. is on, starting from standing, the car is VERY sluggish and not really moving until the revs reach 2000rpm.
really feels like it has no power.

The engine has been replaced 2 weeks ago and no change, all the same.

Post by **Peter.N.** » 09 Jul 2008, 17:27

How did the loss of performance occur, did the power suddenly drop off or has it slowly deteriorated?

MikeT · Post by **MikeT** » 09 Jul 2008, 17:51

I notice yours is an auto? I've come to realise that faults relating to autoboxes can reveal themselves as engine weaknesses and as you've changed engines (if I'm reading you right) I'd be suspecting the 'box.

Does anyone know if the ECU monitors the auto's and controls the engine accordingly?

AndersDK · Post by **AndersDK** » 09 Jul 2008, 20:56

MikeT wrote:Does anyone know if the ECU monitors the auto's and controls the engine accordingly?

There is no ECU to monitor/control the autobox and/or engine on the 1.9TD.

You're thinking later - or uprated - engine & autobox versions.

The petrols will have the 4HP14
except the V6 which have the fully computerised 4HP20
- and the 1.9TD will have the type AL4 autobox.

If the autobox is suspected, first things to check are always fluid level & fluid quality.

wonderd · Post by **wonderd** » 10 Jul 2008, 07:18

I bought the car like that.
I also suspected the gearbox and in the garage they connected it to a computer and checked all the pressures that are supposed tobe there, also they have something called "teaching the pedal" - which means they adjust the opening and closing of the pedal by direction of the sensor on the diesel pump (Bosch).