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        General >> OBD Advice >> Positive LTFT1 and 2
        
(Message started by: Executive on Feb 6^th, 2006, 7:54am)

Title: Positive LTFT1 and 2
Post by Executive on Feb 6^th, 2006, 7:54am

Dear ALL!

I have bought an OBD lead from Alex C. Peper, and I have scan my 24V Cosworth.
I have realized, that the LTFT1 and 2 show a positive fuel trim, both are nearly the same (approx. 12%).
I red the article from Vlad regarding the fuel pressure regulator. I have replaced that to a new one, but no change in the LTFT values.
DO anyone has a tip?

Thank you

Executive from Hungary

p.s. thank you for these web pages!!

Title: Re: Positive LTFT1 and 2
Post by Executive on Feb 6^th, 2006, 5:17pm

I have an additional information. The TPS gives 21% at idle and the idle is also little bit high 800-900rpm. I think, it is not ok.
Is it able to give me a positive LTFT?

Regards,

Ex.

Title: Re: Positive LTFT1 and 2
Post by scorpio_man on Feb 6^th, 2006, 8:58pm

hi there

have you disconnected the battery after fitting the regulator? you need to do this to reset the fueling (about 20mins).

re the tps. it should be nearer 16/17 %. try cleaning the throttle plate with carb cleaner.

hth

Title: Re: Positive LTFT1 and 2
Post by Executive on Feb 6^th, 2006, 10:54pm

Hello Scorpio_man!

No, I did not disconnect the battery after fitted the new regulator.
Is it not enough to clear all DTC via the VE? Because, after a DTC clear, it looks like a full reset of the computer run ???(I mean the continuouse and non cont. monitors included fuel monitor). Is it? or not?

The values of the LTFTs moving up and down depending from the rpm. At idle these are around 12%. These are not a constant values, but the same like before.

Anyway, [] I will do a battery disconnection, and I will cleaning the whole throttle body as you suggested.

many thx for your answer

Title: Re: Positive LTFT1 and 2
Post by Simmo on Feb 7^th, 2006, 6:20am

Andrew said clean the throttle PLATE. When you remove the trunking to the carb there should be a yellow warning sticker telling you NOT to clean the internal surfaces as they have a special coating.

Title: Re: Positive LTFT1 and 2
Post by Executive on Feb 10^th, 2006, 8:17am

Hello Gentlemen,
I have cleaned the throttle body, and I realized, the cord of the cruise control kept the throttle lottle bit open, that was the reason of the 21% of the TP.
I detached the cord of cruise control and tp is 17% at idle, better now.
But,
I done the computer reset for 20 minutes, but the LTFT1 show +6% and LTFT2 show -6% at idle. During a trip both are around 0.
I have a DTC for lack of switch of the bank1 sensor 1 and high voltage of bank 1 sensor 2. What do you mean, what is the problem with that side?
I can sense a little rocking of the idle, i have no idea. The twe front sensirs working ok lokks like.
ANy idea?

Title: Re: Positive LTFT1 and 2
Post by Executive on Feb 10^th, 2006, 8:35am

Sorry, I have two DTC at Enhanced as follows:
P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.
P0138 Downstream Heated Oxygen Sensor circuit Voltage High - Bank No. 1.

Title: Re: Positive LTFT1 and 2
Post by scorpio_man on Feb 10^th, 2006, 10:51am

hi there

you have an issue with the both lambda sensors on bank 1.

check the wiring first on the left of the engine. then it's a case of changing the front one first. the rear one only acts as a cat monitor, so you don't really need to change it.

have a read of http://www.fordscorpio.co.uk/ho2smonitor.htm

hth

Title: Re: Positive LTFT1 and 2
Post by Executive on Feb 10^th, 2006, 9:06pm

does the ltfts depends from the lambda only? what can give me this special tlfts with a new pressure regulator? ignition? lambda mainly? anything else? very small leakage at exhaust system or intake air system?

thx guy!