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Re: 4500 GRX sudden power loss
Posted: 19 Feb 2014 14:51
by bogeyman
Stefan
On petrol efi the Air mass sensor and throttle position sensor in combination dictates the amount of fuel the injectors delivers to the engine through the whole rev range.
Many other sensors also have a say in this process. That is why diagnostic equipment is a must.
With these vehicles , there is a cellphone cradle just in front of the bonnet catch. When you reach to open the bonnet , the phone falls into your hand and speed dials the technician

Re: 4500 GRX sudden power loss
Posted: 19 Feb 2014 16:43
by Tinus lotz
bogeyman wrote:Stefan
On petrol efi the Air mass sensor and throttle position sensor in combination dictates the amount of fuel the injectors delivers to the engine through the whole rev range.
Many other sensors also have a say in this process. That is why diagnostic equipment is a must.
With these vehicles , there is a cellphone cradle just in front of the bonnet catch. When you reach to open the bonnet , the phone falls into your hand and speed dials the technician

like Christo is saying better stop scratching and put the diagnostic tool on ....you are not supposed to touch maf with your fingers hey
graham is diving in sodwana for a week so give him a call next week the earth can be part of your problem .....did you manage to measure fuel pressure ????

Re: 4500 GRX sudden power loss
Posted: 21 Feb 2014 21:53
by martyn

have a look at your air intake pipes between the air flow meter and intake manifold, it might be cracked?
Re: 4500 GRX sudden power loss
Posted: 22 Feb 2014 09:54
by Florian320
I will have a look next time I am at the car (I'm not there at the moment).
Do you think that might have such a big influence?
One more thing I tried: I had a look at the fuel pump relays next to the blower motor and it seemed it was not 100% tight in its socket. In addition there was some sand / dust in the plug which I blew out.
Anyhow: I will try to make an appointment with Graham, then we should know what it is / was.
Re: 4500 GRX sudden power loss
Posted: 23 Feb 2014 15:36
by martyn
I know it influenced mine enough to leave half my rear bumper at Magotla and my "cool demeanour"

at Gerotek.
Re: 4500 GRX sudden power loss
Posted: 24 Feb 2014 09:36
by PathMaker
Hi Florian
I received your voice message on my telephone service but unfortunately you did not leave me your contact details.
Please send me your details so we can discuss an appointment date.
Thanks
Vanessa
Re: 4500 GRX sudden power loss
Posted: 24 Feb 2014 09:48
by Florian320
Hi Vanessa, PM sent. Thank you!
Re: 4500 GRX sudden power loss
Posted: 28 Mar 2014 15:33
by Florian320
Now the car has been at Graham's and Vanessa's place and I got it back.
Graham was quite sure that the fuel pump was the origin of the power loss.
I didn't see it myself but he told me that it had heavy wear on it which suggests that it was the bad guy.
There were no faults recorded in the obd.
The car drives much better now, it is amazing what a change a thorough maintenance by someone who really knows the car can do!
Re: 4500 GRX sudden power loss
Posted: 29 Mar 2014 08:50
by Tinus lotz
Happy to hear some good news .....if your 4.5 is well maintained you shoud get many a happy mile out of it keep us posted