Loss Of Power

[i.vohra]

Hi there

I have an R reg galaxy and have ben having problems with the power suddenly reducing when on the motorway. Seems to get back ot normal whent he car is switched off. Read through the posts about a maf sensor and cleaned it out. Still same problem.

 

Should I replace MAf or what is this VNT sticking

[Smilge]

Hi there

I have an R reg galaxy and have ben having problems with the power suddenly reducing when on the motorway. Seems to get back ot normal whent he car is switched off. Read through the posts about a maf sensor and cleaned it out. Still same problem.

 

Should I replace MAf or what is this VNT sticking

 

Sounds like the car is going into limp mode and could be caused by a variety of things. Usually if you have a MAF problem the idle is usually erratic along with poor acceleration. It could be VNT related where the boost pressure produced by the turbo is adjusted by the variable position of the vanes within it. The VNT actuator moves the vanes. If you have an overpressure fault because the vanes are sticking or not moving to the correct position, the ECU will go into limp mode and limit the power available to protect the engine. You will need to give more information about the car and the symptoms to give the people on here a better idea of what your problem is.

 

Hope this helps

[f0ster]

hello

I have had one of these faults, first of all on the one I was working on the waste gate on the turbo was sticking, the customer elected to replace the turbo,

second, this did not completely rectify the fault, I had to replace the n75 valve along with all of the pipes that control the waste gate position,

the fault is that the boost pressure goes over 2.2kpa which causes the ecu to reduce the power so as to prevent damage, oil gets in to the pipes feeding the control pressure to the ecu preventing the control pressure getting to the ecu in time to reduce power, and so overboost occours, then ecu limp home, the n75 valve was also replaced, this appears to be a common fault on the early ones,

[i.vohra]

Hi there

I have an R reg galaxy and have ben having problems with the power suddenly reducing when on the motorway. Seems to get back ot normal whent he car is switched off. Read through the posts about a maf sensor and cleaned it out. Still same problem.

 

Should I replace MAf or what is this VNT sticking

 

Sounds like the car is going into limp mode and could be caused by a variety of things. Usually if you have a MAF problem the idle is usually erratic along with poor acceleration. It could be VNT related where the boost pressure produced by the turbo is adjusted by the variable position of the vanes within it. The VNT actuator moves the vanes. If you have an overpressure fault because the vanes are sticking or not moving to the correct position, the ECU will go into limp mode and limit the power available to protect the engine. You will need to give more information about the car and the symptoms to give the people on here a better idea of what your problem is.

 

Hope this helps

 

Hi this is a great help. The idle is steady and aceleration is good. Its just when I am doing 70 to 80 on some occassiosn that the power drops and going uphill I start to decelarte. Seem sto come back to normal once I switch off and start the engine again.

 

I am no expert on engines (it took me two hurs to clean the MAF!) Is it best to take to a garage or is the VNT related problem something that can be DIYed.

[Smilge]

Hi this is a great help. The idle is steady and aceleration is good. Its just when I am doing 70 to 80 on some occassiosn that the power drops and going uphill I start to decelarte. Seem sto come back to normal once I switch off and start the engine again.

 

I am no expert on engines (it took me two hurs to clean the MAF!) Is it best to take to a garage or is the VNT related problem something that can be DIYed.

 

Yep sounds like it's going into limp mode. If you do a search on the VNT you'll get a better idea of what to check and IIRC, there is a post where there are photos of the amount of movement you should get from the VNT. First thing you can do is to check all the hoses that connect to and from the boost control solenoid (n75 valve as suggested by fOster), the small filter behind the MAF area on the bulkhead and the VNT diaphragm which moves the actuator. After that you need to get the a diagnostic test done to confirm the problem but I'm not sure VAG-COM works on a Mk1. This will then confirm whether or not the turbo needs sorting out which is quite a big job.

 

Hope this helps.

 

Found the post you need to read

 

http://www.fordgalaxy.org.uk/ford/index.ph...hl=VNT+actuator

Edited February 11, 2009 by Bleeno