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Discussion Starter #1
Hi all,

I am a newbie van owner and I've not posted anything on here worthy yet so I apologise if this is the wrong place to put this but I thought that I should share my very slow van story with you in case it can help anyone else.

The van was slow up hills and seemed to lack in power but started first time everytime.
I changed all the vacuum hoses, blanked the EGR, replaced the intake manifold and its o ring and carried out the cage mod. Still it was slow. I unplugged the MAF sensorand the van ran better so figured that must be the culprit.

Final try before shelling out on a new MAF I discovered that on top of the fuse box above the relays there should be 2 blue 15 amp fuses on their sides. My '02 Caravelle only had 1 in and the other space was empty. I put one in to see if anything changed and woosh! Full speed ahead! Its like a different van A:

Does anyone know what they are for?

However, now the van struggles to start first time. It takes 3 or 4 tries and makes a terrible gear crunching starter motor sound and then it sounds like somethings come off! :(When it does start its great!!:D

Does anyone have any suggestions?

Thanks
 

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I have no info on fuses or crunching noise im afraid :( just need to ask how u found taking the inlet manifold off?? I want to clean mine out from the egr gunk as I've removed egr valve now? I:
 

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got this from another thread, any use?
 

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Thinking the picture is good -- Suspect its the two blue fuses up top left just above the lime labels for "KL15A" The fuses are fitted in an area that is frequently shown to be for relays so !!!

Unfortunately the handbook extracts are not so much use, it only seems to describe a bog standard installation, and even the most basic van is unlikely to conform to the handbooks suggested locations for fuse strips.

Some wiring/fuse guides at http://www.1946vw.co.uk/vwbooks/t4.htm
Some on this sourced from T4 Forum but not sure where its hidden.
 

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Just took a pic of mine, it's positioned slightly differently but there. Anything to do with relay 147? what does relay 147 do?



edit: scrap that, 147 is aircon relay just googled it.
 

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Discussion Starter #6
It is those blue fuses at the top in the picture but still no-one seems to know what they are for - all I know is that by checking them and installing a missing one it sorted my slow and very underpowered van.

Thanks for all the wiring links and diagrams they are always useful but not this time.

My van is starting ok now I think it was just lots of rain and frost that it didn't like.

Parfetto -
Taking the inlet manifold off was easy but the blank is 3mm wide plus 2 new gaskets either side I found that I needed 2x 5mm longer screws to put the exhaust part back on as the standard ones didn't bite. Also fitted a new gasket to the valve itself onto the block.

Get some carb cleaner a toothbrush, gloves and baby wipes (nothing can beat baby wipes for cleaning anything!) and spend sometime cleaning it out follow this link for more tips on how its done.

http://www.vwt4forum.co.uk/showthread.php?t=5258

Its quite easy to do.
The other worthy job was replacing the inlet manifold and the o ring to the turbo with a genuine one from VW (£25) mine seemed tight but once I undid the 10mm bolt that holds it on it was really loose and now I can hear the difference in the cab.
(it holds the top of the dipstick in place with the manifold and you can't see it just feel it and not easy to get to)

I'm no mechanic and I hope this helps anyone.

Thanks
 

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I really want to know what those fuse are for now....
If I find out I'll be back, likewise it would be nice if some of the t4 guru's on here might let us know.
 

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It may be better to ask in the Electrical section....
That's where Upspex hangs out, and if anyone will know, it's him!
 

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the fuses are for power to the MAF, Intake sensors ect. i had a problem with my van for days with the turbo not seeming to be working, after checking all the sensors that could cause the problem ( 5 i think) i decided to remove the engine loom and look for worn wires. when i go to the back of the fuse box, i noticed one of the blue fuses had fallen out, i thought nooo cant be..can it??

put the loom back in, replaced the fuse and it was sweeeet!!
I thinkk the van goes into limp mode if the fuse goes.
 

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Discussion Starter #10
Great thanks mr_blank I knew it might have something to do with that.

If anyone else has a slow van check these fuses first to save a lot of time, effort and cash!!

most problems do seem to be a simple fix!
 

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Many thanks for a very useful thread NorthkiteT: I have learnt something new - which is not hard lol but you never know when that little gem of a tip will come in handy.
 

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Discussion Starter #12
Thanks "u can in a van" I have been on a very steep learning curve over the past 6 weeks after I brought my Caravelle and I have found this forum and its knowledgeable members really helpful so I was passing on the good karma!
 

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Hi guys, I have a 2.5 T4 with this exact same problem. No power, terrible up hills, drives like it has a speed limiter etc.......tried all sorts but great tip on the fuses! Gunna get straight onto it tomorrow, thanks!! :)
 

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These two fuses are for the ecu and n75 valve and egr valve. If your n75 wasn't working because of a broken fuse then the boost control wouldn't work.
 

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Hi everyone, I have the same problem with my van, wont rev round properly at all. I have checked for these 15 amp fuses on the top of my fuse box but they don't seem to be located there. Does anyone know where else these could be because I have dropped down the fuse box and cant seem to find them anywhere?
 

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Just to add to this, I had a new engine fitted in my T4 and after about 800 miles it lost power, after a bit of searching and advice I was told about the 15amp fuses - after a quick check I found one had blown, changed fuse and all great again
 

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I just had a look at mine for these fuses, but I don`t appear to have them. Mine is a 1998 2.5 tdi and I am having this boost issue.
I have replaced all of the vac hoses and I have good ohm`s and voltage at the N75 valve. I have also hooked my wastegate actuator up to a bike pump and it moves freely when I pump.
I suppose my next port of call is to get it on VAG-COM unless anyone has anymore suggestions. I have also unplugged the MAF to see if it makes a difference but I cannot say for definite whether there is any.
 

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Make sure the pipes are in correct order no good replacing like for like if someone got pipes to n75 mixed up

check brake switch another issue that comes with lack of power but vag com probsbly work out cheaper
 
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