New MAF - how long to learn

Hi,

I have just replaced the MAF on my 1997 4.0L V8 GEMS P38 for a new out of the box AllMakes 4x4 one.

Took it out for a test run (on Petrol) and its worse than ever, gutless and no power before about 2000RPM then gets going to 3000RPM and fine reving beyond that.

So I can only assume its trying to learn the new air/fuel mixtures. Was out on the road for about 40min on slow side streets and fast A road, junctions/roundabouts etc.

Should this be enough or do I need to go longer?

If I flick over to LPG there is no problems at all full power from low revs right up to high.

I have checked and the hoses are seated ok and there are not signs of any splits.

any ideas?

Having the adaptive values reset should help. Not well up on the gas guzzlers fuel system.

Single point or multi point LPG system?

Single point systems don't rely on a good seal in the air duct before the ring, whereas multi point and the petrol system does.....

Ensure your intake ducting is fitted correctly with no splits or leaks.

your problem may be your All makes MAF , ive never trusted pattern sensors. the gems ecu can take a little while to adapt,give it a good run with plenty of varied driving to see if it settles . why did you replace it, was the originally faulty,what where the symptoms?

rewmer said:

your problem may be your All makes MAF , ive never trusted pattern sensors. the gems ecu can take a little while to adapt,give it a good run with plenty of varied driving to see if it settles . why did you replace it, was the originally faulty,what where the symptoms?

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I changed it because i had tried everything else an even the independant garage could not think why its been lacking in go in the mid band ranage.

Saint.V8 said:

Single point or multi point LPG system?

Single point systems don't rely on a good seal in the air duct before the ring, whereas multi point and the petrol system does.....

Ensure your intake ducting is fitted correctly with no splits or leaks.

Click to expand...

Hi Saint,

It's an single point so that will explain that.

I have checked all the hoses and ducts and all seem free from leaks, i assume you mean all the pipe work and ducting after the MAF as the air box seems sealed enough.

I will give it another look over, any obvious places to start?.

If it is single point system....they usually don't rely on MAF input for fueling...so if it runs OK on LPG and ****e on Petrol, I agree with Rewmer - could be the new MAF at fault, they have been known to be iffy even from new....

i had tried everything else an even the independant garage could not think why its been lacking in go in the mid band ranage.

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Probably best change your garage aswell then. MAFs are easy to test even with the most basic OBD software.

rewmer said:

Probably best change your garage aswell then. MAFs are easy to test even with the most basic OBD software.

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+1, how hard is it to hold the car at the specified engine speed and read off the air flow figures and compare them to the figures in RAVE?

I had exactly the same last summer.

It could be the fuel trims that need resetting, I bought some software and cables, and the system does an auto calibrate of the LPG and Petrol.

I'm in Lancashire too, it might be worth a try, you are welcome to come over if you want?

Glad to help if I can, others have done it for me from this board (Thanks Don and Mozz)

What make is your LPG system /ECU?

PM me if you want to come over.

Go and buy a Nanocom Evo11
it will tell you all you want to know and if your like me take you as far as your abillity will allow
and save you thousands in money and time.
eg reset adaptive settings,read outputs reset ride heights EAS,the list goes on and on
you wont regret it!

pete38 said:

Go and buy a Nanocom Evo11
it will tell you all you want to know and if your like me take you as far as your abillity will allow
and save you thousands in money and time.
eg reset adaptive settings,read outputs reset ride heights EAS,the list goes on and on
you wont regret it!

Click to expand...

+1 on the Nanocom

pete38 said:

Go and buy a Nanocom Evo11

Click to expand...

Where's the best place to go looking for one?

I have found hawkweyes on eBay but not these

gibby_wls said:

Where's the best place to go looking for one?

I have found hawkweyes on eBay but not these

Click to expand...

Nanocom is much more powerful than Hawkeye