Horrid gas mileage
11-02-12, 01:07 AM
#1
Lead Lap
Thread Starter
iTrader: (8)
Join Date: Nov 2011
Location: Jersey
Posts: 622
Likes: 0
Received 0 Likes
on
0 Posts
Horrid gas mileage
Getting bad gas mileage on my 94 sc400. Getting 200 miles per full tank! That's like 12mpg. I am using exxon or bp 93 octane too.
Each time I drive across town the needle moves. Its frustrating. I've had V8s before so I know they aren't good with gas but jesus, 12 mpg???
I have done new air filter, spark plugs and wires both ngk, oil change mobil 1, new bosch o2 sensors, new engine coolant temp sensor, 12v fuel pump mod, new battery, cleaned iacv, bfi mod for intake, and can't remember what else.
What else can cause bad gas mileage, old fuel filter? I heard ours last and don't really require changing. Might do anyway.
I do sometimes feel a hesitation like a misfire when idling but can't hear it and is random not constant.
I just want that 18 city and 22 highway that
was advertised :/
Although highway gas mileage seems to be like 16mpg. I drive average, not fast or slow. Just looking for other things I should check that causes bad mpg, thanks guys!
Each time I drive across town the needle moves. Its frustrating. I've had V8s before so I know they aren't good with gas but jesus, 12 mpg???
I have done new air filter, spark plugs and wires both ngk, oil change mobil 1, new bosch o2 sensors, new engine coolant temp sensor, 12v fuel pump mod, new battery, cleaned iacv, bfi mod for intake, and can't remember what else.
What else can cause bad gas mileage, old fuel filter? I heard ours last and don't really require changing. Might do anyway.
I do sometimes feel a hesitation like a misfire when idling but can't hear it and is random not constant.
I just want that 18 city and 22 highway that
was advertised :/
Although highway gas mileage seems to be like 16mpg. I drive average, not fast or slow. Just looking for other things I should check that causes bad mpg, thanks guys!
11-02-12, 01:24 AM
#2
[QUOTE=durps;7578584]I do sometimes feel a hesitation like a misfire when idling but can't hear it and is random not constant./QUOTE]
I would look into that.
Truthfully you'd be better off just selling the 94 400 and either getting a SC300 or a 98 SC400, I find either to be more reliable.
I would look into that.
Truthfully you'd be better off just selling the 94 400 and either getting a SC300 or a 98 SC400, I find either to be more reliable.
11-02-12, 01:31 AM
#3
Lead Lap
Thread Starter
iTrader: (8)
Join Date: Nov 2011
Location: Jersey
Posts: 622
Likes: 0
Received 0 Likes
on
0 Posts
I would like to, but I'm about to finally start my career and will leave the sc behind so no plans on getting another one. But I will stay in the lexus family.
I think ill do a compression test and see how they're doing and post up the numbers.
I think ill do a compression test and see how they're doing and post up the numbers.
11-02-12, 07:40 AM
#7
Trending Topics
11-02-12, 09:11 AM
#8
Lexus Test Driver
iTrader: (6)
Join Date: May 2010
Location: Colorado Springs, CO
Posts: 1,442
Likes: 0
Received 4 Likes
on
4 Posts
-a bad MAFS will cause your gas mileage to suffer due to running rich. (bad knock sensors will do the same)
-inappropriately gapped spark plugs
-clogged fuel injectors
any check engine light?
it could be a number of things.
-inappropriately gapped spark plugs
-clogged fuel injectors
any check engine light?
it could be a number of things.
11-02-12, 11:08 AM
#9
Lead Lap
Thread Starter
iTrader: (8)
Join Date: Nov 2011
Location: Jersey
Posts: 622
Likes: 0
Received 0 Likes
on
0 Posts
No check engine lights luckily, although at one point I had one for running lean and another saying running rich at the same time lol.
I will try seafoaming the gas tank and pcv valve.
How can I check timing and if the injectors are clogged?
And no nah consuming any liquids, and intake is clean on the first butterfly valve, haven't checked the inner one. Will take apart and clean.
I will try seafoaming the gas tank and pcv valve.
How can I check timing and if the injectors are clogged?
And no nah consuming any liquids, and intake is clean on the first butterfly valve, haven't checked the inner one. Will take apart and clean.
11-03-12, 04:32 AM
#12
Yes. Especially in terms of the VVT-i 1JZ you have tremendous torque at a mere 2400rpm in a 2.5L engine which means during normal, reasonable driving you simply do not have to rev much to get up to 35,40, or 50 miles per hour. With an NA 2JZ there isn't much going on until 4,000 rpm and more revving is required to achieve half of what any 1JZ can do under normal acceleration. I tend to think this holds true more for the VVT-i version, however. It will never be stellar fuel economy with any JZ engine but thee less you rev them and the more you can keep the revs down the less gas it will burn.
11-03-12, 08:30 AM
#13
Yes. Especially in terms of the VVT-i 1JZ you have tremendous torque at a mere 2400rpm in a 2.5L engine which means during normal, reasonable driving you simply do not have to rev much to get up to 35,40, or 50 miles per hour. With an NA 2JZ there isn't much going on until 4,000 rpm and more revving is required to achieve half of what any 1JZ can do under normal acceleration. I tend to think this holds true more for the VVT-i version, however. It will never be stellar fuel economy with any JZ engine but thee less you rev them and the more you can keep the revs down the less gas it will burn.
11-05-12, 04:03 AM
#14
Thread
Thread Starter
Forum
Replies
Last Post
bowen.chau
RX - 1st Gen (1999-2003)
390
11-19-23 09:00 AM
