Jenvey Bodies May Need Refurb?

[GTI6BOY 29]

We just had our cti remapped by longmans?

 

I am well pleased with how the car is now but it has started to do something strange.

 

Before it was mapped the bodies were out of balance so they balanced them back up then mapped the car

 

While driving at below 50mph the problem happens but over 50mph problems not there

 

If you keep at a steady speed whether it be 30mph 40mph 50mph it judders briefly and pulls back then is normal, it does this every 10sec.

 

If you are going through the gears the car is amazing with no probs

 

I have been told by a few peeps that the jenveys need rebuilding...they are a couple of years old.

 

Any ideas

[Miles 331 1 Cars]

Sounds more like the mapping could be slightly out or sensor, The bodies go on for yr's, I;ve had mine for 8 yr's and they are good as new still, they are only a tube and a buttlefly so wear is hardly anything

[GTI6BOY 29]

longmans said it cant be the mapping.

 

garage i use have just sent some away to be rebuilt as there was play in them.

[base-1 17]

Jenveys are good but they're still a mechanical part, they need checking

 

Probably a sensor though as Miles says

[GTI6BOY 29]

sensor???

 

the only senor is the tps and that is new

[Mongo 0]

did it do this before it was mapped?

 

Does it sort of bog down slightly, until you press the accelerator then it starts to pick up and is fine?

 

My brand new motorbike does this after i put on my power commander 3 (which alters the fueling map) and does not do it with it plugged in. It deffo sounds like a fueling issue if its the same symptoms as above. Do you have a backup of the maps to alternate between them?

 

My jenveys are over 10 years old and i only just balanced hem the other day (they werent out of sync by much at all).

[Tom Fenton 1,542]

Check for any play in the spindles, this is really the only bit that could wear although unlikely.

[danpug 1]

longmans said it cant be the mapping.

 

garage i use have just sent some away to be rebuilt as there was play in them.

 

 

Longmans would say that! As above, did they do it before they mapped it? If they didn't then surely thats the problem.

[hodgy 0]

my webbers are doing the same thing

[16v205 9]

Sounds like a tps fault to me. Can you access the ecu to read the realtime figures? If so I bet the tps value is bouncing about when the throttle pedal is kept still. The fault would be less noticable as the engine picks up speed.

 

Rich

[GTI6BOY 29]

it did do it before but only every now and then.

 

but they had to adjust the right two as these were out of balance and its done it since then

 

why would Longmans the best engine builder and mapper in the country tell me that????

 

if one of my butterflys is open more than the other then i could have problems

 

cant be the fuel as they have not touched the fuel on the map

[GTI6BOY 29]

everything was fine on the laptop...defo not the tps

[danpug 1]

it did do it before but only every now and then.

 

but they had to adjust the right two as these were out of balance and its done it since then

 

why would Longmans the best engine builder and mapper in the country tell me that????

 

if one of my butterflys is open more than the other then i could have problems

 

cant be the fuel as they have not touched the fuel on the map

 

I guess its not the mapping then though something has obviously happened to make it get worse. Longmans are probably the most expensive engine builders/mappers in the country i'll give them that!

[base-1 17]

sensor???

 

the only senor is the tps and that is new

What?!

 

Crank sensor, water temperature sensor, air temperature sensor.....

[Alastairh 47]

Why don't you take it back and say its not running correctly as it should considering you paid how much to get it fixed.

 

Even if its not there fault they will have a better idea seeing it in person than just guessing on the net...

[GTI6BOY 29]

base-1 - those sensors arnt my problem...i know that for a fact, what i ment the only sensors on the bodies. they are all new anyhow

 

cant just take it back as its over 300 mile round trip and i use my car eveyday

 

i go through pug-performance so its not expesive at all for me

[base-1 17]

Well you didn't say that did you

 

So you got the car remapped, they balanced the bodies, everything is new except the bodies, they didn't change the fuel map.

 

So they only adjusted the timing? There could be an air leak somewhere? Get it to Longmans so they can check the bodies and decide if they need a rebuild, only way to rule them out

[Bonzai 2]

i had something similar last year when i was at the ring, felt like there was a hole in the mapping, but as it wasnt all the time it wasnt that at fault. We thought it was the TPS at first, but in the end i cleaned up the CPS and it was cured. I agree with miles theres really not alot that can go wrong with jenveys

[Mongo 0]

Well you didn't say that did you

 

So you got the car remapped, they balanced the bodies, everything is new except the bodies, they didn't change the fuel map.

 

So they only adjusted the timing? There could be an air leak somewhere? Get it to Longmans so they can check the bodies and decide if they need a rebuild, only way to rule them out

 

 

He said it done it before it went to longmans also but not as frequent. Howcome longmans never touched the fuel map?

[GTI6BOY 29]

i only took it down there to map out the problems i had with the car ie cold start.

 

to do this they change the rpm to match water temp...thats all

[GTI6BOY 29]

just jogged my memory...the following day i cleaned my engine bay but i put sergical gloves everywhere, 1 over each body, ecu plug, spark plug holes, removed coil pack

 

im thinking i have play in my 2 left bodies and the right was sligtly un-balanced and was compensting for it, where they balenced them back up it has caused problems.

 

if you press number 2 buterfly it makes a clicking sound and moves ever so slightly

[GTI6BOY 29]

took a vid earlier...turn the sound up and you can here my problem

 

also only does it when the engine gets up to temp

 

Edited March 23, 2008 by GTI6BOY

[Bonzai 2]

have you tried hooking a laptop up and data logging?

 

It really does seem similar to what i experienced, would be worth just giving the crank sensor a quick rub imo, only takes 5 mins.

[Tom Fenton 1,542]

I'd suggest getting a wideband lambda on there so you can see what the fuelling is doing when it starts stuttering like that. What ignition system is it running, how old is it all?

[GTI6BOY 29]

was on the laptop about a week ago and everything was sweet as

 

its about 3 years old all of it, and im running efi managment...thats what longmans use