IN NEED OF HELP!

Right, first of all sorry to add to the hundreds of "losing power" threads on this forum but I am really starting to lose my rag with my Golf!So before I drive it off a cliff I thought I should ask for some help!

A bit of background:

I have just had the engine rebuilt and took it to a specialist to have it tuned as it was really hard to start and was not running right. When I got the car back it starts pretty much perfectly and runs great. However……..

When I first start a journey it drives great, very smooth with power throughout all the gears. After driving for about 20mins I lose power during or just after increased acceleration. It probably drops down to about 60MPH or under. At this time, the car starts to slow down with my foot to the floor, other times it slowly speeds up. I get power back after easing off a bit and lose it again on hard acceleration. I should mention at this point that my idle is a bit inconsistent and does occasionally drop right down after loosing power. I am also due an oil & filter change as I have done 500 miles since the rebuild (not sure if this is relevant).

Things I have done so far (as part of the engine rebuild):

New Ht leads and plugs
New Fuel pump
Used an inspection camera to look inside of tank - looks fine.
New distributor Cap
New injectors

Should my next port of call be the accumulator? Warm start seems to be fine.  If any one could help point me in the right direction it would be greatly appreciated…. I'm running out of patience and more importantly, Money!  

Forgot to mention,

Before changing the fuel pump I had major power loss on the dual carriage way. Fine smoke was coming from the drivers footwell that smelt a bit like plastic?? So I pulled over and let the car cool down. I thought it might be the fuel pump relay but the garage told me they checked and there was no sign of damage.

I have only done about 20 miles with the new fuel pump and not seen any smoke since this one time…. but it does worry me.

Any ideas?  

Anyone got any ideas?  

What's the fuel filler neck like? Does the fuel pump make more noise when you get this problem? Have you looked at the fuel lift pump inside the fuel tank?

Thanks for your comment,

I haven't noticed the fuel pump making more noise, will try and check that. Will check the fuel lift pump tomorrow but the garage should have checked it.

Heres the fuel filler neck:



Does the rust on the outside represent rust on the inside?

It's at the top you really need to look at, open the filler cap and shine a torch inside, look for any holes. Then have a look underneath the wheel arch at the top as that's where the mud sits.
if there's holes in the filler neck water and dirt gets into the fuel system causing alsorts of problems.
 

Thanks I will check this when it stops raining!

Quick Update,

Took car out for a quick drive, now seems to be down on power the whole time and got noticeably bad after sitting at 3000 RPM for a few mins.  

mark1gls said

It's at the top you really need to look at, open the filler cap and shine a torch inside, look for any holes. Then have a look underneath the wheel arch at the top as that's where the mud sits.
if there's holes in the filler neck water and dirt gets into the fuel system causing alsorts of problems.

Shined a torch inside and couldn't see any hole, looked clean. No other visible damage at the top either. Also, am I right in thinking that I don't have a fuel lift pump as it an 83 GTI?    

start here:
http://vwgolfmk1.org.uk/forum/index.php?page=topicview&id=how-to_2%2Ffuel-tank-cleaning_3

if smoke came out the driver side id be lookign at ignition switch and wiring, the fusebox and relays are (should be!) on the passenger side. maybe theres an alarm/immobiliser on driver side thats fried

Right guys, bit of an update because I've still got this problem and in need of urgent help please….

I've tried everything stated above and more and the problem has got a little better, but … It now seems to dramatically lose lower and often backfire whenever I take a hard left corner???

Things I have done:

Refurbished the Distributor
New Fuel pump (Bosch)
Fuse box
Refurbished Metering head
New Fuel tank
Ht leads
fuel filter  
Spark plugs

Any help please  

when you say new fuel tank, was it a pattern 'gti' tank? if so check the swirl pot inside, it should look like the one in the link above. if its just a metal cup you have been incorrectly sold a diesel tank which is just not good enough for a GTI.

I would take it off and demand your money back, the more people who do this the sooner these p[laces will stop selling these diesel tanks as GTI when they clearly are not!

if you dont want to do that the alternative is fit a swirl pot somewhere (tricky to find space on kjet gti!) and fit a lifter pump in the tank from late cab/rocco or g40 shape polo. alternatively an inline pump at the bottom tank outlet feeding swirl pot, that then feeds the main. even more tricky to find room for that though!!

Thanks for the info, I will have to check this out. So if I have been sold a diesel tank could this be the problem to the power loss round corners do you think?

Thanks

yeah this is what I'm thinking, the diesel swirl pot is fine for thicker diesel oil plus the lower demands from the diesle engine I guess, but not much good for petrol?

the proper swirl pot has non-return flaps in which stops the fuel getting out of it once it flows in.

although thinking about it if you take a hard left all the fuel should slosh over to the right side of the tank where the fuel pump outlet is, I would expect it to be worse when turning shrp right as all the fuel will go over to the left starving the pump…

maybe have a look at your engine mountings and the rubber boots to the main pipe from airbox to the inlet manifiold, make sure there are no splits in the folds

Can you tell me where you sent your metering head and fuel distributor for refurbishment? I am trying to get mines done too.
Many thanks
Ritchie