[LS1] HELP!!! Ridiculously High Fuel Consumption 2002 LS1 Monaro 23l/100km++!!!!

[neilkris]

Hi All,

Got a massive issue with my LS1! Ive replaced the below parts and am seeing fuel consumption of approx 23l/100km!!! And it only marginly better on the highway, approx 18l/100km! I am absolutely babying this car as (ive also had to replace the ratios and other bits in the diff so cant use the excuse im right foot heavy..)
- Genuine Injectors
- NGK Spark Plugs
- NGK Spark Plug Leads
- O2 Sensors
- Coolant Temp Sensor
- Fuel Pump
- Fuel Filter
Its always ran on Caltex VORTEX 98 fuel, ALWAYS!
Also had a MAFLESS Tune done with a VCM Performance OTR! Im at a loss to what else can be stuffed! When it was running like crap (prior to all this work) it was getting about 17l/100km in town and about 10l/100km on the hwy, now i cant get anywhere near those numbers and its supposed to be running well??

 

[Reaper]

First things first - any codes checked by a proper scanner (not a ebay toy)

 

[ari666]

Also had a MAFLESS Tune done with a VCM Performance OTR!

why on earth would you get a mafless tune on a stock car????? why on earth would VCM even perform that mod? i was under the impression they had a very good rep in the LS1 world...

 

[VBhero]

Did this poor consumption after the OTR and Tune? Or is it something that has just started happening after a while?

As for Mafless on a stocker? 6 to 1, half dozen to another mate. There are gains to be had with the early LS1s, as the MAFs up until VZ presented an intake restriction. Is it worth it? That's up to the owner really.
Personally, I found that I had better throttle response, and the car felt a lot "snappier" if that makes sense. In saying that though, it wasn't long after that, that I cammed it...

 

[Darcon666]

why on earth would you get a mafless tune on a stock car????? why on earth would VCM even perform that mod? i was under the impression they had a very good rep in the LS1 world...

So they can charge a shite load of money for an extra 5-15rwkw... lol.

 

[ari666]

There are gains to be had with the early LS1s, as the MAFs up until VZ presented an intake restriction.

biggest bunch of bullshit in the LS world, and yet everyone still sucks into it like its a fact.

 

[neilkris]

**** comsumption after replacing all the above, really not sure whether it was before tune or after as it had a miss which was pissing me off, so kept replacing parts till i found out one of the o2 sensors wasnt giving a reading.. Apparently was an easy wiring fix, whilst this was being done i also got them to do the mafless tune

 

[Reaper]

See post #2

 

[VBhero]

**** comsumption after replacing all the above, really not sure whether it was before tune or after as it had a miss which was pissing me off, so kept replacing parts till i found out one of the o2 sensors wasnt giving a reading.. Apparently was an easy wiring fix, whilst this was being done i also got them to do the mafless tune

Yep, that's going to make it a little harder to pin down. I would do as Reaper suggested and get a decent scanner on it, check for codes, then get back to the tuner. Heck just go back to the tuner, they should be able to scan for codes, then they can log what is happening, checking outputs from sensors and see what the tune is doing.
It could be a sensor /s or could be something stuffed in the tune