petrol injection times

anyone know how wide is the injection pulse at idle,on a 4.6 thor v8?the injection time on mine is 4 to 4.2 ms,is this correct? or at least in the ball park?

sassanach said:

anyone know how wide is the injection pulse at idle,on a 4.6 thor v8?the injection time on mine is 4 to 4.2 ms,is this correct? or at least in the ball park?

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Why would you want to know that, is it not running properly? Injection pulse is produced by the ECU, I believe it's a digital signal that is varied by software so should not be subject to deviation from what is needed unless a sensor is giving the ECU duff info.

About 2.9 with a hot idle on mine, higher when cold.

EDIT: Mine is GEMS, but it should be similar I guess.

well ive just had the adaptive values reset,the injection times are approx. 4ms.i am trying to fix a "idle trim out of range error" on both banks which keeps re-occurring.lambda sensors are "switching"fine but the engine just seems a tad rough.of course I could be looking for pots of gold at the end of rainbows.......or I may have an issue.hence the question.

rewmer said:

Yep that sounds a little long to me. I would expect to see 3- 3.5ms. Whats the MAF reading at idle with all loads off ?
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The pulse width seemed a bit long to me too... It was me that reset the adaptive values,dont worry all the usual culprits are spot on - Maf was 23.5 Kg, well within the parish etc. I've not got any black book values of injector pulse width for Thor motors - never needed them before.I cant really compare with Gems data either as they run a fixed fuel rail pressure of just over 50psi.

Did it run any better on the way home ?

yes it does run better than before I must admit,still seems a tad rough at idle tho+no fault codes.i did a 100 miles last night and boy oh boy can this thing drink,i,m convinced ny 8.2 litre v8 Eldorado is better on fuel...

sassanach said:

yes it does run better than before I must admit,still seems a tad rough at idle tho+no fault codes.i did a 100 miles last night and boy oh boy can this thing drink,i,m convinced ny 8.2 litre v8 Eldorado is better on fuel...

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Maybe that's the cam ? I know its more expensive,but running on petrol for a few more miles will help get all the trims sorted.Then you can trim your gas after a recheck/refit.
Also forgot to say to check the flexplate isn't cracked.