2000 TD5 surging is back! HELP!

[blackapache]

righto so a quick search will see you find my previous surging woes, but for the uninitiated here is my problem; i have engine surging under light throttle. most noticeable in fifth gear after cresting a hill and having just the tiniest bit of throttle on to maintain 100kms/hr it also does it ever so slightly in 4th and sometimes 3rd. if i give it a bootful its fine.

previous to this i checked the wastegate, disconnected the map the maf, the clutch sensor... replaced the harness, changed the hoses to silicon jobbies (one was delaminated) did a full service checked the brakes weren't sticking and replaced the fuel filter - all of these things helped but didnt fix it.

my real woes began again yesterday I had recently installed an Allisport intercooler then finally hooked up my boost box and installed a newer NNN ECU from Jose at Td5 Inside. The car drives much better, but i need to adjust the wastegate as its a bit sluggish till about 2200rpm then it goes like a cut snake. It pulls hard in fifth from 80km all the way to 120 and wants to keep going till i let it off but there is no surging so i dont think its the wastegate as my surging is seemingly lower in the rev range. i did have a tiny bit of residual oil at the red plug which i cleaned but that made no difference.

im leaning towards TPS or a buggered fuel pump, when i turn the ignition on it sounds fine no spluttering.. i do have a newer long range tank the ally one, but i do run my tank top to bottom most weeks with only about 10L left before i fill it up... my filter was still good at last change though.

anyone have any suggestions? ive done the easy/cheaper fixes and would love to know for sure before i drop $450 on a TPS or who knows how much on a fuel pump..

any help would be much appreciated.

[jimr1]

I had a miss on my dt5 at about 100 plus ks . I found It just by luck . I changed the injector harness , and while putting It back together noticed that the wiring harness that runs along the block under the head had worn through some of the wiring . Probably vibration , you would never see the problem because It's on the side facing the block , plus It had a good coat of oil as well . I was wiping the oil off the wires just to clean them up , when I found bare wires , they could touch the block and make a short . Cleaned them up , re taped them , put them in a sleeve , never had a miss again . I don't know if this is your problem , but worth checking out , before buying a new pump !!. Jim .

[blackapache]

I had a miss on my dt5 at about 100 plus ks . I found It just by luck . I changed the injector harness , and while putting It back together noticed that the wiring harness that runs along the block under the head had worn through some of the wiring . Probably vibration , you would never see the problem because It's on the side facing the block , plus It had a good coat of oil as well . I was wiping the oil off the wires just to clean them up , when I found bare wires , they could touch the block and make a short . Cleaned them up , re taped them , put them in a sleeve , never had a miss again . I don't know if this is your problem , but worth checking out , before buying a new pump !!. Jim .

yeah cheers for that, i checked all the harness a while back traced out the whole thing.. may be time to do it again..

[blackapache]

anyone else wanna chime in... ? be much appreciated for any advice.