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        General >> Give/Need advice to/from others >> 2.5 TD Air flow meter
        
(Message started by: SteveO on Jun 28^th, 2011, 1:04pm)

Title: 2.5 TD Air flow meter
Post by SteveO on Jun 28^th, 2011, 1:04pm

Fault code reader at my local garage indicates that the air flow meter signal drop off at about 2200 revs. That matches with the power loss at the same time. Given the cost of a new one, is it worth looking for a second hand unit or are they too sensitive to risk a used one?

Cheers,

Steve

Title: Re: 2.5 TD Air flow meter
Post by Highlander on Jun 28^th, 2011, 1:39pm

I use second hand petrol ones all the time, might be a bit harder to find a diesel one though..

Have you tried cleaning it?

http://www.fordscorpio.co.uk/cleanmaf.htm

Title: Re: 2.5 TD Air flow meter
Post by SteveO on Jun 28^th, 2011, 2:11pm

Cleaned it with carb' cleaner as a first option but made no difference. The output from the MAF dies at 2200 revs, according to the readings from the laptop and fault code reader.
A new one costs about £90ish.

Title: Re: 2.5 TD Air flow meter
Post by Highlander on Jun 28^th, 2011, 2:45pm

Seems unusual for it to fail at a certain rpm?

what are the symptoms the car is showing?

You had the problem with the sensor in no.1 injector recently didnt you?

Title: Re: 2.5 TD Air flow meter
Post by SteveO on Jun 28^th, 2011, 2:56pm

Yes, I thought that #1 injector was the problem(based on the symptoms but not diagnosed with a fault reader) so put up with it because of the cost of a new #1 injector.
Now I have some funds so I got it put on a fault reader. That's when it came up with the MAF signal dying at the the same revs.

Title: Re: 2.5 TD Air flow meter
Post by a-way on Jun 29^th, 2011, 12:44pm

I searched for a second hand one a year ago... then gave up and bought second hand one from a 2,5 td vauxhall... i didn't notice any difference in performance (but I drove 2 weeks with maf disconnected so... ). It still works at the moment.

Title: Re: 2.5 TD Air flow meter
Post by SteveO on Jun 29^th, 2011, 2:23pm

Ran the car with the AFM disconnected, no difference. Does that mean the fault lies elsewhere?

Title: Re: 2.5 TD Air flow meter
Post by a-way on Jul 1^st, 2011, 8:04am

When you disconnect MAF then there should be no turbo kicking in (no normal acceleration past ~2000 rpm).
My MAf reads ~4V during idle and 14V at 3000rpm. I don't know if that is normal but at least it reads something ;D

Title: Re: 2.5 TD Air flow meter
Post by SteveO on Jul 3^rd, 2011, 4:21pm

Hmmm. I get to 1750 revs and feel the turbo and it pulls well until 2200 revs then loses power. It will accelerate but only at snails pace. The symptoms were the same after disconnecting the MAF.

Title: Re: 2.5 TD Air flow meter
Post by a-way on Jul 4^th, 2011, 7:46am

My turbo did its work "limp mode" for two weeks... got figured it out last saturday though... replaced maf with the correct one (last numbers 164), cleaned EGR - nothing... lastly I took off vacuum pipes from EGR vacuum valve... sucked and.... membrane broken... switched the two valves and voila- turbo works at correct rpms and none of that black smoke that made plants lose their leaves:)

Title: Re: 2.5 TD Air flow meter
Post by SteveO on Jul 4^th, 2011, 9:17am

Cheers, that sound slike an avenue to investigate. Where is the membrane you mentioned? Is it in one of the pipes or in the ERG valve itself?

Title: Re: 2.5 TD Air flow meter
Post by a-way on Jul 4^th, 2011, 9:21am

The vacuum valves are next to ABS pump (to the left). There are two identical black vacuum valves there. The top one was bad - the one where egr vacuum hose goes to - so I swapped them.

Now i'm looking for a new one to replace the bad valve... there are two and altough car runs well there is a reason why there are two valves.

Title: Re: 2.5 TD Air flow meter
Post by SteveO on Jul 4^th, 2011, 10:38am

Cheers a-way. I have just scrapped my old 2.5TD so will dig out the valves from there and see if they make a difference. My old one was auto and this is manual so will look at the part numbers to see if they are compatible.
Steve

Title: Re: 2.5 TD Air flow meter
Post by a-way on Jul 4^th, 2011, 10:53am

should be.... same valves were fitted to 1994 to 2000 2,5 diesel transits and 1995+ escort 1,8 diesel's aswell according to parts e-catalogue.

Could anyone explain to me though why is there 2 vacuum valves? the upper one works for EGR and the lower for turbo and ?

Title: Re: 2.5 TD Air flow meter
Post by SteveO on Jul 4^th, 2011, 12:14pm

Just to confirm, are we talking about the upper and lower black boxes in this photo?

http://i577.photobucket.com/albums/ss211/stevework69/EGR.jpg

Title: Re: 2.5 TD Air flow meter
Post by a-way on Jul 4^th, 2011, 12:22pm

jep... ATM written on top

Title: Re: 2.5 TD Air flow meter
Post by SteveO on Jul 4^th, 2011, 12:26pm

Thanks, will get cracking after work this evening. Fingers crossed.....

Steve

Title: Re: 2.5 TD Air flow meter
Post by a-way on Jul 7^th, 2011, 11:29am

on 07/04/11 at 12:26:28, SteveO wrote:

Thanks, will get cracking after work this evening. Fingers crossed.....

Steve

how did it work out?

Title: Re: 2.5 TD Air flow meter
Post by SteveO on Jul 7^th, 2011, 1:39pm

Not had time yet - kids, work, broken toilet flush, filthy cheating lying builders not turning up..... one of those weeks. Will try to get round to it on Sunday or Monday.

Title: Re: 2.5 TD Air flow meter
Post by Matt on Jul 8^th, 2011, 10:41am

Do the Later TD's have the diaphgram valve?

Title: Re: 2.5 TD Air flow meter
Post by shooshyneman on Jul 10^th, 2011, 10:41am

Check the vacuum pipes for leaks I had one rubbing on the fan belt which holed it and gave the same symptoms