1.6jx pulsing at top end of exceleration

[hulky]

Adice please my van has developed a pulsing on full exceleration.

I will try to describe best I can..last year on our trip to France I noticed when the van was working hard up hills mostly.. It was as if I was pressing gently on and of the excelerator causing the van to slow a bit then excelebrate.
It's done it for a bit now but I am wondering whether it's the turbo or the injection pump ?
It only does this at top end of revs..ie foot to the floor.

Any ideas would be great
John

[dave friday]

when did you change the fuel filter...what have you tried/replaced?

[hulky]

I havent't changed anything yet dave
..the van had a full service before our summer hols last year
I will give the van a sevice this weekemd..good idea

[dave friday]

Try undoing the water drain [bottom of the fuel filter ] let a bit of fuel/water out...
See what that does.

[hulky]

Ok i have changed fuel filter and oil still doing the same.it only does it at high revs ?

[MGP]

Do you have the clear plastic fuel pipes?

Also does your fuel filter have the plastic valve in the top that the return attaches to?

[hulky]

yes to both.are you thinking there may be air getting in ??

[MGP]

Yes any the pump uses its internal pressure for the timing advance so any air in there will play havoc.

The plastic valves do have a habit of going a bit wonky so its worth keeping a spare.

[hulky]

ok i will check all pipes and try to replace valve on filter.can you get fuel filter valve at most car parts shop ?

[MGP]

I have only ever fitted genuine valves due to too many problems with them in the past.

If you dont have clear fuel pipes on supply and return it is worth fitting them as it makes diagnosing fuel problems much easier.

[hulky]

they are clear ones i have.i have allwas had a small air bubble in mine but never caused any problems in the past 8 years.

[MGP]

Ok if there are no air bubbles moving in the supply or the return then replace the valve and go from there.

[hulky]

Ok I have revved engine while looking at fuel supply line and there was quite a few bubbles going up the harder I revved the more bubbles came up.I then checked the connection to the fuel filter it has a small jubilee clip..I pushed pipe on a bit more and retightened up and checked supply line and no more bubbles.So road tested and in high revs it was still pulsing as if sucking in air

[MGP]

Ok it sounds like its worth replacing the rubber fuel hoses. Have you changed the valve yet as the valve can allow air to be sucked back up the return under load

[hulky]

Thanks for the help.

I checked the return at same time and there was no bubbles..I replaced all rubber pipes 3 years ago ? am going to order the valve soon.

Putty you wern't closer