What shall I replace now?

Hot starting problem I've got (quite a few of you know it's been an ongoing problem for the last year    ops: )

checked injector's - about 4-5 months ago, not the best but don't leak

fuel pressure - drops intantly when the car is switched off.. right so:-

replaced the check valve in front of the fuel pump

tried a spare metering unit I've got (which, thanks to Rich I know it's good…. after killing his car  ops: sorry mate)

just swapped over the fuel accumilator… broke a fuel line so replaced the whole lot (thanks Rich again   )

Still losing pressure

so what's next?? it's not leaking anywhere

thinking start from the beginning, bite the bullet and replace the injectors + 5th injector as I can't think of anything else it could be

so chaps.. I don't want any comments when I go to leave Gaydon and it doesn't start! it's not like I haven't been trying  

warm up regulator? :dontknow:

Phil

when you turn the ignition on can you hear the pump priming? Before you try to start it ?  

If not why ?

If you can forget it ………  just an idea……… :wink:

I have had the same problem for years with mine. Got worse recently though. When it fires, it is only thumping on 2 or 3 cylinders for about 10 secs, then the other/s kick in…?

I think it is probably leaky injectors with the petrol in the cylinder making the spark plug too wet to fire or something, until it is all pushed out of the exhaust… :dontknow:

Chudd, nope pump doesn't prime, tried finding out if it should prime, but came to the conclusion it's the early fusebox/relay/wiring setup that doesn't prime and the later one's do  :dontknow: still unsure though

cabriaulait, my understanding of the WUR is that it wouldn't cause a loss of pressure if it was faulty.. but with the pressure tester's valve closed (which closes the fuel feed to the WUR) the pressure still drops

Al, sounds the same as mine, when hot, once it's started it runs like a bag of nails for the first 30 seconds (ish), few blips of the throttle clears it

thought the rough running when it starts was due to the pressure needing to build up enough to run all the injectors  :dontknow: but I've replaced everything that's suppose to hold the pressure (check valve, metering unit's tested good, and the accumilator)

if it's no good once the injector's are replaced I'll leave it.. thinking about giving it the G60 treatment when it comes off the road again so it will go  digipants

What pressure reading are you getting after switching with engine off? You should have around 2 bar after the accumulator.

while the engines running the pressure is right (between 45-55psi)

as soon as I switch the engine off it drops to nothing, 10 seconds later the pressure 'blips' to about 20psi for under a second, then back to nothing

if that makes sense?

Where are you checking the pressure? I would start after the accumulator and work your way up until you find the leak.

PhillTMK1GTI said

Al, sounds the same as mine, when hot, once it's started it runs like a bag of nails for the first 30 seconds (ish), few blips of the throttle clears it

Same here - a little help via the throttle seems to clear it quicker…

PhillTMK1GTI said

thought the rough running when it starts was due to the pressure needing to build up enough to run all the

Would make sense if yours ins't priming, though my pump is DIY wired through a switchable relay so I can leave the pump run for 5 to 10 secs before starting and I still get the same problem, which is why I am conviced that it is down to leaky injectors!

Sorted out the oversize rings I needed for the valver now anyway, so that project is back on track, so hopefully all will be cured…by way of replacing the engine!  :mrgreen:

dubboy said

Where are you checking the pressure? I would start after the accumulator and work your way up until you find the leak.

checking it between the metering unit and WUR where haynes suggests

where else can it leak from as I've replaced all the fuel lines yesterday with Rich's lovely braided stuff

Al, you cheat!   won't bother rewiring the relay with a switch then

one thing I did try is running the car with the 5th injector unplugged, made cold starting difficult and had no effect on hot starting

The accumulator holds the pressure for 15 to 20 minutes when you switch off . Right !  

So the problem must be from the accumulator to the metering head then on to the injectors ………Ahhh its all pointing to those injectors then !

You have changed every thing else  :dontknow: You might have to bite the bullet abd but some new ones . I did and mine runs lovely now .



Cheers………….

think it could be time to admit defeat and buy some injectors  

going to test them again anyway on the weekend, the spray pattern isn't the best but they're all within flow limits and didn't leak when I checked them last

won't be until spetember till I can buy new ones though  :cry: she'll have to wait!

I'll dig this thread out when I replace them and let you all know

http://cgi.ebay.com/ebaymotors/81-82-83-84-VW-Golf-GTI-Scirrocco-Fuel-Injectors_W0QQcmdZViewItemQQcategoryZ33554QQihZ007QQitemZ170009746889QQrdZ1

 Cheaper than uk prices ……….?

good find chudd, works out at about 70? dont it?

US $74.95
?40.53


If you win on maiden bid ! He wanted $20.00 for shipping so about ?55.00 . I paid ?123.00 for my 4 new ones .

Not certain about quaility etc but at less than half UK prices  :dontknow:

:y: nice one.. gonna have to wait a month or so though

right, gave the injector's (and 5th injector) another test this weekend

no leaks there at all  :cry:  and the spray pattern has improved since I last checked it  8O

the pressurised fuel is definately getting back to the fuel tank and after reading the Haynes manual again (almost know it word for word   )

it's either

Fuel pump check valve (replaced about a month ago - new VW)
Fuel accumulator (borrowed a used one.. possible they have the same fault I guess)

when doing the pressure test with the valve closed the pressure drops at the same speed

I'll bite the bullet and get a new accumulator and see if that sorts it (almost everything else is new now anyway   )

Hi Phil,

Any chance I could borrow one of your spare accumulators to see if they fix my problem?

Cheers

Rich

:y: shouldn't be a problem mate, can arrange to meet you tonight if that's ok? bit busy for the rest of the week (already!)

got my number so give me a call any time after 7:20 :wink:

Awesome :y:

I'll give you a call then…

Cheers Phil

Rich