Engine sometimes needs excessive cranking to start

[Lukey. 381]

More often than not my engine takes quite a long time to start, maybe 5 seconds of cranking, once started its absolutely fine and when it does fire up it does burst into life it doesnt chug and crawl into action, it just can take a while to get fired up.

It usually takes longer once the car is warmed up then parked for an hour or so then started again.

My thinking was fuel pump or filter but the fact that its fine when started and goes like it should under the hammer im thinking theyre fine.

I also thought could it be plugs or leads not giving good spark?

I have seen mentioned on vortex that there is a one way valve in the fuel lines that keeps pressure for cold starting that can start leaking pressure back out but i cannot find any more about it or where it even is?

VAGCOM has no complaints its all clear.

While i was hunting for a solution i also noticed the short little pipe running from the inlet manifold to the fuel pressure regulator is fraying a bit, can i get this short run of pipe by itself?

Id have a good look myself but tried installing etka but it needs 1280x1024 min resolution so wont work on my 1280x800 laptop :-(

[craggsy 91]

Could be battery on it's way out.

As for the hose then a piece of silicon vac hose will do

[Lukey. 381]

do you know the inner diameter off hand? i havent got any relevent sized clips to fasten it back on if i got the wrong size tubing. Ill see if i can try a new battery my stepdads just got a new one for his 3.2 so ill see if i can swap and see if it starts any better.

[Lukey. 381]

i swapped batteries and it still does the same thing so cant be battery, my battery also worked absolutely fine in his car, better actually as its a 700A and his is 600A. Didnt just turn his engine over rather swing it round the drive

[Lukey. 381]

i couldnt get anywhere further with this problem, so ive forked out for the bentley manual, it lists like 4 things i can try so ill have to try them and see if it solves the problem

[T0NYVR6 2]

Doesnt the crank shaft speed sensor cause this kind of problem when its starting to go?

[Lukey. 381]

would this be the case even though vagcom never gives faults?

[lowvr 0]

possibilty could be alternator not charging the battery properly (may still be charging, but not well enough.

[Lukey. 381]

it still happened with a brand new fully charged battery.

Im after a fuel pressure gauge to check pressures and residual pressures, im pretty sure its to do with fuel pressure

[Lukey. 381]

hmmm after having a look for guel pressure testing kits does anyone know of a decent one that doesnt cost hundreds?

[jamiehamy 0]

I had the same problem. I did two things ( stupidly at the same time!) and the problem is solved.

I swapped the fuel pressure regulator for one on a spare I had (that never had the same issue).

I also 'reset' the ECU by unplugging the battery.

4000miles later and she starts no problem when warm now.

I suspect it was the fuel pressure regulator to be honest as I've had the battery out a couple of times over the last few months.

If you can get one either new, or from an engine that never had the issue hopefully that might help

J

[Lukey. 381]

its gonna be one of 2 things, the one way check valve thats in the fuel pump assembly and not available seperately (conveniently) or like you say the regulator.

it wont be the ecu as that has nothing to do with fuel pressure, its the 2 valves

Having searched for a decently priced pressure testing kit and even asking local garages if they have one ive turned up nothing, so figure im not going to waste at least £50 on a test kit and put the money towards the new parts, though i really would like to test it so i can find out exactly whats the cause.

Spose if i replace them one at a time ill see whats the culprit, though then ill be pissed off if its the second part that fixes the problem and i wasted money on an unnecessary part lol, cos they both arent cheap parts

[Gazbarber1982 3]

Mine's the same. I've changed the FPR from 3 bar to 4 bar from my older VR and it still does it. I'm also lookin for fuel pressure tester. You can get them on ebay for about £25 but you'll need a bit of hose so you can put the gauge between the end of your fuel line and the fuel rail.

[Lukey. 381]

Ive seen them on ebay but was a bit dubious as to their quality, ive heard a lot of people get duff gauges that read totally wrong

while the valve in the pump is built in and not replaceable, you can get a one way in-line fuel valve for about £5 so i think im going to get one of these first and put it on the feed line right next to the fuel pump, if it doesnt solve the problem its only £5 not £50 wasted

[bpm 0]

I had a similar issue when I first put the VR6 into the mk2. turned out it was the ignition switch that was causing it

[Lukey. 381]

Ive bought an inline one way valve for the sake of a fiver to see if it sorts it.

[Gazbarber1982 3]

Any luck with the pressure test?

[Lukey. 381]

i havent been able to even obtain use of a test kit, no one uses them or if they do they arent letting me use it.

VW actually made a retro fit valve for the VR6 fuel pump as it was so common for this scenario to happen it was cheaper to fit this part than replace the fuel pump, ive ordered it but they dont have any in UK and they wont know if germany have any for a couple of weeks, as it was only £12 im looking at this first, so im just waiting at the moment

[Lukey. 381]

Got the retrofit valve from VW took 2 weeks to appear from germany. Looks like a good little kit, you get everything you need to fit.

this is how old it is, had the original sticker on the bag, ancient logos.

the part is older than my car!!

[Lukey. 381]

Install was as painless as it looked, looks very OEM, it even fits into the original clips for the piping.

Time will tell if its worked.

[Saunders82 0]

Did this work mines always done this too. Some dutch guy at edition 38 heard it and thought it could be a bad earth for the starter motor. I've changed the starter the temp sender fuel filter as well now then I gave up lol

[Lukey. 381]

no it didnt but no fuss for 12 quid, ive ordered a bnib bosch fpr from germany for 30 quid so waiting on that arriving

[sep 68]

did you cure this problem? im having the same thing, changed the fuel pump relay and was brill for a start or three then went back to the way it was.

[Lukey. 381]

yea, i replaced the fuel pump one way valve, fuel pressure regulator and injectors

[Vw_owner 1]

try the crank sensor anyway even though its not showing on vagcom, atleast thats one more thing to tick off the list!!