Under 8 MPG (5 Viewers)

[sogncab]

I have no codes after swapping the fusible link.

@BILT4ME You screwed me bud. Poking around in the woods this evening, I got that same coolant sensor code.

I thought I was well outside of your envelope, but not the case. You were right, I was wrong.

 

[lelandEOD]

Signature suggests that poster does indeed have HDJ80, so it doesn't seem relevant in a discussion of fzj80 mpg woes.

It is relevant insofar as you guys should all convert to turbodiesels.

 

[Speedytech7]

You guys have made me feel good about the health of my 93 and its old ass EFI. 285s, stock gears, mostly stock actually really. 13.6mpg average and I've cruised on the hwy at 65 and gotten 16 a few times.

 

[jjdeneen918]

No updates regarding getting my shop to dive into it. I’m still waiting on getting my STI tuned & dyno’ed.

Yesterday my EGT gauge went crazy. It signals at temps over 1600 degrees, ran around 2000 degrees.

Today after work, EGT sensor immediately rang upon start up. There is no way it would get that hot within seconds of starting.

Just another thing to have looked at.

I will update with mechanic gives ideas.

 

[CJK]

Not sure I saw anybody else with a turbo respond regarding their mileage.

I’m turbo’d on 35” tires with stock gearing. I consistently get 12-13 mpg.

Same driving conditions (mix town/highway)

 

[AussieHJCruza]

12-13 mpg corrected (~17-18 litres per 100) on the highway, Safari Turbo kit + FMIC, 4.10 diffs, 315/75R16 on heavy beadlock rims, little bit of armour and H151 transmission

Pushing hard through the hills, mid 20s per 100 or more

Was pretty similar to what I've got from N/A trucks.

 

[jjdeneen918]

I FINALLY got my rig back to Topline Performace late last week.

Hopefully will have some definitive answers soon, hopefully this week.

Looking into my O2 sensor codes, A/C fixed.

Additionally getting my OEM auxiliary fan, that I’ve had for a few years, installed.

 

[BTLSHP]

I had been fretting about a fuel mileage issue in our '94 as I was getting it ready for my daughter to take on a 700 mile trip. I had the hood up and engine running looking for a noise on start-up (loose belt eventually). Anyway much to my surprise a fine spray of fuel was spraying out of the fuel return line towards the block......

 

[Broski]

I had been fretting about a fuel mileage issue in our '94 as I was getting it ready for my daughter to take on a 700 mile trip. I had the hood up and engine running looking for a noise on start-up (loose belt eventually). Anyway much to my surprise a fine spray of fuel was spraying out of the fuel return line towards the block......

Time to replace all the rubber lines especially gas lines.
At this point there 30 years old.

Please do this before sending your daughter off on a long trip.

 

[BTLSHP]

Time to replace all the rubber lines especially gas lines.
At this point there 30 years old.

Please do this before sending your daughter off on a long trip.

Yes, I need to go about this systematically. We have done the major coolant lines including the PHH (not rear heater). I got both return lines in the fuel system now I need to look at a diagram of the rest of the system and the vacuum lines near the firewall. A mechanic did look it over pretty well before the trip.

The car became a modest celebrity last week as the trip was about documenting her and a friend's rock climbing for their sponsor. The car became the setting for much of the non-climbing dialog and the video crew fell in love with it.

End of a day of climbing, The Coliseum, Summersville Lake WV.

 

[Broski]

Yes, I need to go about this systematically. We have done the major coolant lines including the PHH (not rear heater). I got both return lines in the fuel system now I need to look at a diagram of the rest of the system and the vacuum lines near the firewall. A mechanic did look it over pretty well before the trip.

The car became a modest celebrity last week as the trip was about documenting her and a friend's rock climbing for their sponsor. The car became the setting for much of the non-climbing dialog and the video crew fell in love with it.

End of a day of climbing, The Coliseum, Summersville Lake WV.

View attachment 3585975

It looks like a very clean rig !

 

[BTLSHP]

It looks like a very clean rig !

Yes, its basic role was to get from DC to a weekend spot in WV that routinely required chains in winter. Other than that it was garaged. I still have the original factory carpet mats stored away. They have less than a month's use.

Looking to get the 1st & 2nd row leather & foam replaced with either LCH or Katzkin in the next few months.

 

[Archy]

Yes, its basic role was to get from DC to a weekend spot in WV that routinely required chains in winter. Other than that it was garaged. I still have the original factory carpet mats stored away. They have less than a month's use.

Looking to get the 1st & 2nd row leather & foam replaced with either LCH or Katzkin in the next few months.

View attachment 3586205

Wow, agreed on a clean rig. If you replace the front seat leathers and want to sell the originals let me know. They look in better shape than mine! I am in MD too.

 

[jjdeneen918]

Rig has been at the shop for 2 weeks now.

Got a call yesterday about my O2 sensors.

Owner said the rig is running rough & very rich. Which it is.

Cold start, it’ll run rough til it warms up. Usually evens out at about 100-120 degrees.

Running rich makes sense as I’m getting horrible gas milage.

Shop said that’s why it’s throwing both O2 codes, but it’s not necessarily because of the O2 sensors that were recently replaced.

They said by next week they should have an answer.

Any theory’s as to why it may be running this way?

 

[jjdeneen918]

Side note/question:

The A/C. The shop put dye in the A/C system last week to track down why my A/C system keeps loosing its charge.

They said they can’t track down a leak.

Last time they charged my system, it had perfect A/C for about 2 months of driving, but just quit after that.

My A/C has been to the shop probably 4 times now. Each time there have been seals replaced, valves replaced, they have been under the dash too.

This has been a very frustrating experience.

Why is this so darn difficult to actually fix?!

 

[Broski]

2 weeks to get the that Info, you could have got that your self in 10 minutes.
Now your looking at the internet for answers, I think you need a new mechanic JMO.

 

[BTLSHP]

If A/C leak is not visible in the obvious places that sort of leaves the evaporator which may or may not leave traces of dye at the drain tube. Do not ask why I learned....

 

[elripster]

Rig has been at the shop for 2 weeks now.

Got a call yesterday about my O2 sensors.

Owner said the rig is running rough & very rich. Which it is.

Cold start, it’ll run rough til it warms up. Usually evens out at about 100-120 degrees.

Running rich makes sense as I’m getting horrible gas milage.

Shop said that’s why it’s throwing both O2 codes, but it’s not necessarily because of the O2 sensors that were recently replaced.

They said by next week they should have an answer.

Any theory’s as to why it may be running this way?

Yes, a few possibilities actually. It would be very helpful if you noted the Vf1 and Vf2 voltages. It's a starting point as to what the controller is trying to do. You will need good O2 sensors for those readings to mean anything though.

I really think you should check out that link I posted and go through measuring the sensors in it. If you have a few that are pushing rich beyond what the ECU can trim (would be low Vf2 readings...) it can lead to rich which can kill the O2's which default max rich to protect the engine from detonation. That = lots of fuel and potentially toasted cats. Otherwise, you are at the mercy of the shop....

Frank

 

[jjdeneen918]

Well, I’m currently at the mercy of the shop.
Currently out of town for another couple weeks. Dropped off the rig before I left, wanted it fixed while I was away.

 

[JoeCova]

Tire pressure is set to factory, aired at Costco with their air mixture.

This likely wont help with mpgs but what do you mean by "factory?" The OEM tires were a P-Metric tire and if your tires are currently an LT you would need to look at load inflation tables to have the correct PSI.

e.g.

P275/70R16 = 2480 at 32 PSI / 1.1 derated P tire = 2255
LT275/70R16 = 2295 at 45 PSI (Load inflation must be equal to or greater)

So I would double what your tires are P, SL, LT etc and what the corresponding PSI is.