MAF TpS Adjusted

[bob h]

Hi All, well today I bit the bullet and checked the Tps and MAF. The tps was set a bit low but the surprise was the maf was set at 2.7. Well, with the help of this forum and many days of reading and re/re/reading I knew [in theary] just how to do the job. The tps is now set at 3.2 and the maf is set to 1.3v. Went for a good drive and it feels good, but not quite as much performance as before. Now to check my fuel consumption compared to before. Sorry, but the veh is a D1 3.5 V8 with the 5AM MAF. Fuel used before was 450/470ks to a tank mainly around town and 640/670ks on a trip. retty happy with the consumption before so am waiting expectantly/hopefully to see a good deal better now. Many thanks to all who unknowingly helped me with the excellant directions. Bob

[PhilipA]

I hope that is 0.32 volts on the TPS. However it doesn't really matter as long as it is under 0.49.
Regards Philip A

[bob h]

I hope that is 0.32 volts on the TPS. However it doesn't really matter as long as it is under 0.49.
Regards Philip A

Yep, your right I should have typed 0.32v on the tps. Thanks for all your info that I used. Not too scared of doing DIY stuff anymore. Should I see better fuel economy now? Bob

[PhilipA]

Depends on the weight of your right foot!
Seeing you seem to have really good economy now, I do not think you will see much better, although the MAF adjustment will lean it a bit across the range.

Regards Philip A

[bob h]

Depends on the weight of your right foot!
Seeing you seem to have really good economy now, I do not think you will see much better, although the MAF adjustment will lean it a bit across the range.

Regards Philip A

Thanks phillip, time will tell, Bob

[disco98SE]

Hi Bob just wondering how your fuel ecomony turned out with you MAF set at 1.3v. I found that mine was way out too I think the guy that installed lpg system played with it. I tried it at 1.25v and was getting 25lt/100km. am now trying 1.5v as the a/f ratio indicates 15.5 ish (lpg) 14.6 ish (petrol). used to get 17lt/100km before the lpg system was installed.

Cheers Geoff

[Grimace]

Good to see someone getting good economy figures let alone at such high CO trim!

As for your MAF settings, you should not be worried about a drop in power at 1.3V on the CO trim, I'd consider that normal.
In my limited knowledge I have found that anything under 1.7V is generally a slight detriment to power with a slight increase in economy.
Your AFRs should be slightly lean across most of the rev range / load points (although I have still found them to be over rich at idle, even at 1V).

With regards to your original setting; 2.3-2.5V was recommended to me recently by a power tuner and is apparently the best setting (3.9L V8) for flat out racing!

I think the late 3.5 were the most economical of the bunch. Previous posts of mine will show that I once had a vehicle that maintained consumption under 20L/100 with an automatic classic sporting 5" lift and 37" tyres on standard gearing. I regularly saw 16L/100 in highway use. It was great!!!
Unfortunately I never got figures for that vehicle in standard trim.

Keep us posted on the figures and any improvements.