Another poor mpg thread. (1 Viewer)

[jonheld]

I believe this is the fuel pressure regulator.

No. The FPR looks almost exactly like the FPR on the 3FE and is almost in the exact same location relative to the fuel rail. That plastic guy is a VCV valve for the evap system off the charcoal canister. You're smelling fuel because that's off the purge port of the canister that feeds back into the intake.

 

[jonheld]

Had him send me the air filter too. Anything else you can think of.

I would add a new PCV valve and grommet.
Anything that could lead to vacuum leaks in the top half of the motor. Same concept as the 3FE.
I believe the 1FZ is more tolerant of top end vacuum leaks than the 3FE, so it won't idle as horribly as the 3FE would with just a small leak. That's likely because the 1FZ ECU has a larger adjustment window and can correct/adjust more, ie. slightly smarter. It's still 1980s technology, just 2nd generation EFI.

 

[LS1FJ40]

I did the PCV and grommet already. I followed your tune up list for the most part. I believe.

I would add a new PCV valve and grommet.
Anything that could lead to vacuum leaks in the top half of the motor. Same concept as the 3FE.
I believe the 1FZ is more tolerant of top end vacuum leaks than the 3FE, so it won't idle as horribly as the 3FE would with just a small leak. That's likely because the 1FZ ECU has a larger adjustment window and can correct/adjust more, ie. slightly smarter. It's still 1980s technology, just 2nd generation EFI.

 

[White Stripe]

Go buy a wideband air fuel ratio gauge. The one I bought was 130 bucks on ebay. once u can monitor your air fuel ratio you will know exactly how it's running otherwise your just guessing.
APSX V2 Anti-Glare D2 Digital Wideband O2 AFR Gauge & Sensor Kit Black & BLUE | eBay

 

[junior80]

I'm getting about 8mpg in the city and about 9.5mpg on the highway. wtf. I knew it was thirsty but this is a bit too silly.

better have another thorough read through this thread and change some stuff.

 

[paladek]

welll.....I'm very happy I'm better than you !!!!!?????? Ha !!!!!

on my LX450 SC I get consistently 320KM - 330KM for a fill-up 78 to 82 litters premium gas !!!!! that's about 24.8 l/100K !!!!!. That's about 11.3 MPG !!!!!! (totally ridiculous in my opinion.....!!!!)
So I used to complain a lot about this dismal consumption.... 11.3 MPG (totally outrageous in my opinion....) but I see it can get a lot worse !!!....so....I have to consider myself lucky.....!!!!

 

[MODist]

At 5520lbs on 285/75/R16 MT's and stock gearing I am getting 13.3mpg in mixed driving. I haven't checked highway mileage since my tuneup. I am due for new tires this weekend which should help. I'll report back after my coming trip this weekend. Crossing my fingers for 15mpg on the highway.

 

[retrofive]

Trim the fat.
91 landcruiser fj 80

 

[MODist]

Trim the fat.
91 landcruiser fj 80

What fat? That is empty without the rear seats or any armor and 1/4 tank of fuel.

 

[junior80]

oh wait up, I have 285s on, how do I recalculate that?

 

[MODist]

oh wait up, I have 285s on, how do I recalculate that?

Depends on how new or old they are but as an average take your mileage and multiply by 1.06.

 

[junior80]

Depends on how new or old they are but as an average take your mileage and multiply by 1.06.

just worked it out and I have surprising news; It's still s*** LOL

I just fitted new plugs gap checked (1 heat range colder than oem due to the svi LPG system), new plug leads, AFM clean, upper engine clean, I have the timing advanced, I run it on 98octane, I have a new rotor button and dizzy cap to go onto it just haven't picked it up yet.

this engine had a very basic lpg system on it a while ago which was removed because it was backfiring through the airbox, this does damage the AFM but i'm pretty sure the PO had that replaced. It also may need a valve job. i can't actually find any record of hardened valve seats being fitted into the head and there's a pretty detailed history of everything done to it over the years.

maybe I need to do a compression test.

 

[KWalkerM]

11mpg city, 12mpg Freeway. somehow I always manage to have the nearly the same MPG city/freeway. Guess I need to slow down on the freeway instead of doing 75mph all over keeping up with traffic.
315s, fully load 1FZ

 

[MODist]

just worked it out and I have surprising news; It's still s*** LOL

I just fitted new plugs gap checked (1 heat range colder than oem due to the svi LPG system), new plug leads, AFM clean, upper engine clean, I have the timing advanced, I run it on 98octane, I have a new rotor button and dizzy cap to go onto it just haven't picked it up yet.

this engine had a very basic lpg system on it a while ago which was removed because it was backfiring through the airbox, this does damage the AFM but i'm pretty sure the PO had that replaced. It also may need a valve job. i can't actually find any record of hardened valve seats being fitted into the head and there's a pretty detailed history of everything done to it over the years.

maybe I need to do a compression test.

What tires and pressure are you running? My mileage improved going from 35psi to 40psi.

 

[MODist]

11mpg city, 12mpg Freeway. somehow I always manage to have the nearly the same MPG city/freeway. Guess I need to slow down on the freeway instead of doing 75mph all over keeping up with traffic.
315s, fully load 1FZ

Yea going above 65mph drops the mpg quick.

 

[junior80]

What tires and pressure are you running? My mileage improved going from 35psi to 40psi.

bit lower than that at the moment, I have 30 in them now because it was just that little bit too rough at 40psi

 

[MODist]

bit lower than that at the moment, I have 30 in them now because it was just that little bit too rough at 40psi

Yea I know what you mean. 32 rides real nice. I take it up to 40 when traveling long distance on the highway. I end up airing down to 15 once I leave the pavement.

 

[retrofive]

38psi seems to be the best compromise for me. (315/75/16, MTr's)

 

[retrofive]

Yea I know what you mean. 32 rides real nice. I take it up to 40 when traveling long distance on the highway. I end up airing down to 15 once I leave the pavement.

Offroad the stauns are set to 16. Drop from there as needed in my cases.

 

[KWalkerM]

38psi seems to be the best compromise for me. (315/75/16, MTr's)

How is the road noise on the MTRs in an 80? I had old school MTRs on my 60 and I could hear their racket above the v8 and flowmaster, awesome tire but terrible for road noise