help using diagnostic on 4.5

[brakedust300]

Finaly got everything working today..

The problems im having are rough running, bad fuel ecconomy (well worse than normal!) and i have a loss of power.

So can anyone help with how to read what comes up on the computer (i have the blue cerb in the background, is this the best one for my 1998 4.5?)

Is there a rough guide for what the 2 lamba's should be at and all the other gubbins?

Cheers in advance

[brakedust300]

Ahhh... jumped the gun there a little, just read through the help section.

throttle 1 = 14.8%
throttle 2 = 21%

with the engine off so there is something to start with!

also when running my Baro pressure hardly changes.... could this have somthing to do with her running badly?

[brakedust300]

Got my own little thread here...

right i will continue the self conversation...

After reading through this thread
http://www.pistonheads.co.uk/gassing/topic.asp?h=0... (very useful) I'm still unsure how to adjust my individual throttle bodies on either side, I'm probably being very stupid, but can someone point me in the direction of the adjustment screws?

Edited by brakedust300 on Saturday 20th September 17:42

Edited by brakedust300 on Saturday 20th September 17:43

[Nefarious]

The two throttle should be roughly the same (c.15% at idle), and the adaptives as close to zero as possible. Do a search on here for balancing throttle pots for how to go about adjusting.

Baro pressure is a measure of atmospheric pressure, so unless you're in the middle of a typhoon, I'd hope that it would stay roughly constant!

Edited by Nefarious on Saturday 20th September 13:11

[Nefarious]

This thread should sort you out:
http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

[brakedust300]

Nefarious said:

This thread should sort you out:
http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

Yep thats the one i've been looking at, got some good info... but i dont know which screw/nut etc i use to adjust the bodies..

[Nefarious]

I've had a quick look, but can't seem to find the thread I was looking for.

There's a post by Joo (Trackcar) expaining step-by-step how to balance the TPs. I guess do a search for "Throttle pot" and look through the results.

Alternatively, have a look through Joo's old posts. IIC it was early/mid 2007, but I might be completely wrong about that.

[Nefarious]

Sorry, I should have added:

There's not screw as such to move the TPs - there are two retaining screws which you loosen, and you move the whole body of the TP to adjust.

BTW - I don't pretend to be an expert, but if you need any "enthusiastic amateur" help then I'm in Edinburgh.

[brakedust300]

Nefarious said:

Sorry, I should have added:

There's not screw as such to move the TPs - there are two retaining screws which you loosen, and you move the whole body of the TP to adjust.

BTW - I don't pretend to be an expert, but if you need any "enthusiastic amateur" help then I'm in Edinburgh.

Ace... im new to all this so trying to take my time and not rush it....

Which 2 screws is it or just a point in the right direction, if you are floating around dundee anytime soon give me a shout

[Nefarious]

I hasten to add I haven't actually done this, so take my advice with a pinch of salt.

Follow the fuel rails all the way to the front of the engine and you'll see the two little blue plastic things that are the TPs. Each one has two screws to attach the body to the engine, but if you loosen them then the TPs can turn on their mounts (with the centre bits being held with the metal rod thing).

I'm reliably informed that very small movemenst make a big difference.

I've actually got to go and have a poke over mine later today to test both temp sensors, so I'll have a closer look and report back...

[brakedust300]

right, found them and got both set at 14.8, reconnected everything, re-set my adaptive maps and she already sounds much better!

although my adaptive are at 37 ish so need to fiddle lots more

[brakedust300]

looks like my near side TP is goosed... its running up from 14.8 - high 30's!

sound like its fooked? it seems to be ok with the engine not running, but as soon as i fire her up its all over the shop

[brakedust300]

Right i have swapped the TP and its all over the shop on the other side now, so looks like it's definitely the TP, would this mess up the adaptive as well?

[brakedust300]

How do i put up the pictures of the data up?

[Redmist336]

I was going to state that I'd never adjust throttle bodies based on TPS. Not only because they could be faulty, but they should also be able to be adjusted independently of throttle rotation. Vacume is the only reliable way to set throttle position.

[Nefarious]

Certainly does sound like one of the TPs is fubar

brakedust300 said:

How do i put up the pictures of the data up?

Set the diag program to full screen and press the "Print Screen" button on your keyboard.

Open a paint program (e.g. Photoshop or MS Paint), open a new document, and click "paste".

Save that file as a JPEG or whatever, and load it up to Photobucket or similar image hosting site.

Take the url of the full screen image and type it into a post here with [IMG] in front of it and [/img] after it.

[brakedust300]

Nefarious said:

Certainly does sound like one of the TPs is fubar

brakedust300 said:

How do i put up the pictures of the data up?

Set the diag program to full screen and press the "Print Screen" button on your keyboard.

Open a paint program (e.g. Photoshop or MS Paint), open a new document, and click "paste".

Save that file as a JPEG or whatever, and load it up to Photobucket or similar image hosting site.

Take the url of the full screen image and type it into a post here with [IMG] in front of it and [/img] after it.

Winner, cheers again..

i went for a run with her all hooked up and the TP both seem ok now, she ticks over better than ever but coughs a lot on 1st start up and is very very lumpy on power....