2000 s10 zr2 poor fuel economy - S-10 Forum
S-10 Forum is the resource on GM S-series trucks, Suspension, engine information, Body Modifications, painting tutorials.  Modifications to suit every need, budget and whim

2000 s10 zr2 poor fuel economy

Go Back   S-10 Forum > Specific Model Forums > 2nd Gen Forums > ZR2 - BlaZeR2 - Highrider
New User? Register Forgot Password


 
LinkBack Thread Tools
Old 11-29-2011, 01:34 PM   #1
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
2000 s10 zr2 poor fuel economy

I own a 2000 chevy s10 zr2 automatic that is getting horrible gas mileage. the truck itself has 151k miles but has a used engine with 85k that has new plugs wires cap and rotor thermostat with new housing and water pump. It seems to be getting like 9 mpg and doesn't seem to be getting better mpg on the highway either. I've tried changing the tps sensor, recharging the k&n air intake, and cleaning the maf sensor. Is there anything else I can do that might fix the problem like a fuel filter or something else. the tranny seems to shift at higher rpm like 2500 and close to 3000 so idk if I need to get tranny work
Old 11-29-2011, 01:43 PM   #2
Registered User
 
94ZR2CAN's Avatar
 
Age: 39
Join Date: Nov 2009
Posts: 77
Location: Ontario Canada
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

I'd bet tranny.............sorry. Mine shifts at 1800-1900 RPM yours sound really high
Old 11-29-2011, 03:04 PM   #3
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

I mean it only shifts high when i really try accelerating pretty hard at red lights. if i accelerate slow and smooth it shifts at like 1900 so I'm not sure. Should i do a tranny fluid and filter change?
Old 11-29-2011, 05:13 PM   #4
Registered User
 
Join Date: Mar 2010
Posts: 30
Location: Lowell,MA
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

I would change the fuel filter first. It should be just before the driver rear tire on the frame rail. If you haven't already.
Old 11-29-2011, 05:54 PM   #5
FIX BROKE STUFF
 
rustyg's Avatar
 
Age: 28
Join Date: Aug 2008
Posts: 536
Location: MB, Canada
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

trans sounds fine to me, change your fuel filter first and see if that helps. have you had it checked for codes? what does your temp guage say? if it doesn't get up to operating temp (or thinks it doesn't), the engine will stay in Open Loop mode which in turn would cause poor mileage.
Old 11-29-2011, 10:01 PM   #6
Registered User
 
Hoettel's Avatar
 
Age: 23
Join Date: Nov 2011
Posts: 43
Location:
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

drive like a granny lol maybe it was geared down how big are your tires
Old 11-30-2011, 12:30 PM   #7
Registered User
 
Join Date: Oct 2011
Posts: 26
Location: Vancouver, WA
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

My trans was shifting way high and I thought it was going bad on me. Then one day my SES light came on and it was a TPS code. I replaced the TPS and it cured my problem. Can't say for sure yours is the same problem, but I posted my experience in case it may help.
Old 11-30-2011, 03:06 PM   #8
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Yeah im definately gunna change the fuel filter soon. I already changed the TPS and it seemed to help alot but nothing very noticeable, i hope the TPS i bought isn't junk. As for gears I'm pretty sure its just stock 3.73 with 31in tires so I don't think its geared down too low. My truck might not be getting up to operating temp since it does seem like it stays cold, how would i fix the open loop mode problem?
Old 11-30-2011, 03:17 PM   #9
FIX BROKE STUFF
 
rustyg's Avatar
 
Age: 28
Join Date: Aug 2008
Posts: 536
Location: MB, Canada
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

i would hook a scanner up to it if you can to see if in fact it isn't reaching temp. where does the needle on your temp guage sit? since you said you changed the t-stat, next step would be the temp sensor on the left side of the block.
Old 11-30-2011, 07:18 PM   #10
Registered User
 
992drjimmy's Avatar
 
Age: 42
Join Date: Sep 2005
Posts: 1,814
Location: Decatur INDIANA
User is: Online
Temp should be just under 210. Just had this problem on my jimmy. Was only getting up to about 150 and 10mpg.

sent from HTC G2 on t mobile using autoguide android app.
Old 12-01-2011, 07:35 PM   #11
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Yeah I don't drive too far to school about 4 miles or so away and the temp seems to be only at 150 or so, so this is probably the problem. How would i fix this?
Old 12-01-2011, 10:05 PM   #12
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Would a bad knock sensor be the problem?
Old 12-02-2011, 04:12 PM   #13
FIX BROKE STUFF
 
rustyg's Avatar
 
Age: 28
Join Date: Aug 2008
Posts: 536
Location: MB, Canada
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Temp sensor should fix it, not sure about the knock sensor. Why do you ask?
Old 12-03-2011, 12:45 AM   #14
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

ok when my truck was the warmest, the temp was about 170 or so. It was in between the 1/4 line and the half so I'm not sure if it's not warming up completely
Old 12-03-2011, 02:00 PM   #15
FIX BROKE STUFF
 
rustyg's Avatar
 
Age: 28
Join Date: Aug 2008
Posts: 536
Location: MB, Canada
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Might not be, teh needle should sit just under the half mark at 190*.
Old 12-03-2011, 07:19 PM   #16
Registered User
 
Zonk's Avatar
 
Age: 66
Join Date: Nov 2011
Posts: 56
Location:
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

I just bought my 96 ZR2 and it seems like the temp gage is right around 160. I am going to have to check it with the Laser because my first tank Fuel economy is about 14 around town.
Old 12-03-2011, 10:46 PM   #17
Registered User
 
sam336's Avatar
 
Age: 24
Join Date: Aug 2009
Posts: 600
Location: Edgewater, MD
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Quote: Originally Posted by Zonk
I just bought my 96 ZR2 and it seems like the temp gage is right around 160. I am going to have to check it with the Laser because my first tank Fuel economy is about 14 around town.
My old 99 had the same problem. Ended up being the t stat.
Old 12-04-2011, 09:57 AM   #18
FIX BROKE STUFF
 
rustyg's Avatar
 
Age: 28
Join Date: Aug 2008
Posts: 536
Location: MB, Canada
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

This^^

Not getting up to proper temp will cause your engine to run in open loop mode. It tells the ECM to use different fuel trims which is what causes bad mileage. Don't trust the gauge, get a scanner with live data or like Zonk said, a laser is almost as good.
Old 12-04-2011, 11:53 AM   #19
Registered User
 
Join Date: Oct 2011
Posts: 26
Location: Vancouver, WA
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

I had a P0128 code yesterday and I bought a scanner with live data and found the engine max temp after 5 miles was 138 deg. A thermostat cured that problem. Now I'm at 190-195 according to the scanner.

I'm getting 13.4 mpg. I hope that goes up. But the heater works a lot better now
Old 12-04-2011, 02:17 PM   #20
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Yeah i'll take 13.4 mpg any day lol how much was the scanner?
Old 12-04-2011, 03:36 PM   #21
Registered User
 
Join Date: Oct 2011
Posts: 26
Location: Vancouver, WA
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

The scanner was $100. It's on sale from $130 at Autozone. It's the actron CP9575 and has live data and it Internet upgradeable. I upgraded it just after I got it. Just needed to use my mini USB cable to connect it.

Autozone has a rewards card thing also. You get $10 credit for registering the card online (emailed to you in a couple of weeks) and after 5 $20 purchases you get $20 credit. After ball joints, water pump, window motor and rear brakes I easily got the credit. I used my credit when I got the scanner.

I could go to Autozone and use there scanner but that only gave me the codes. I needed a scanner that I could have with me and see the live data. They won't let you "borrow" theirs for that.

So now that I've got the scanner I'll probably not use it much, but I have it and when a code does come up it won't drive me crazy not knowing what it is waiting for Autozone to open and find out what it is.
Old 12-04-2011, 09:09 PM   #22
Registered User
 
sam336's Avatar
 
Age: 24
Join Date: Aug 2009
Posts: 600
Location: Edgewater, MD
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Quote: Originally Posted by rustyg
This^^

Not getting up to proper temp will cause your engine to run in open loop mode. It tells the ECM to use different fuel trims which is what causes bad mileage. Don't trust the gauge, get a scanner with live data or like Zonk said, a laser is almost as good.
Your exactly right about it staying in open loop getting poor fuel economy.
Old 12-06-2011, 08:54 PM   #23
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Well anyone know of what and where the best and cheapest scanners are at?
Old 12-07-2011, 10:22 AM   #24
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

My truck does seem to be running really rich. When i start my truck up at like 730 am in cleve where its probably like 40 degrees in the morning and the exaust is smoking alot. I do run an open straight pipe with no muffler though.
Old 12-17-2011, 11:15 AM   #25
Registered User
 
'01 ZR2's Avatar
 
Age: 19
Join Date: Dec 2011
Posts: 32
Location:
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

go and gut your cats! i was getting 10 miles to the gallon and every thing on the truck was fine so i decided to check the cat and it was clogged, so i gutted it and i get 17-20 now, try it.
Old 12-17-2011, 11:20 AM   #26
Registered User
 
'01 ZR2's Avatar
 
Age: 19
Join Date: Dec 2011
Posts: 32
Location:
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

its not the trany, thats what i thought it was doing the same thing yours was doing Tshak2000zr2 and it was the cat now every things all good.
Old 12-17-2011, 11:49 AM   #27
Registered User
 
Join Date: Oct 2011
Posts: 26
Location: Vancouver, WA
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Quote: Originally Posted by Tshak2000zr2
Well anyone know of what and where the best and cheapest scanners are at?

I know this is a little late to answer your question, but I just found this. If I'd have known about it I would have gotten this instead of the one I got from Autozone. It does everything my scanner does and a lot more.


I'll be placing my order for this right after my next payday.

http://www.ultra-gauge.com/ultragauge/index.htm
Old 12-17-2011, 06:19 PM   #28
FIX BROKE STUFF
 
rustyg's Avatar
 
Age: 28
Join Date: Aug 2008
Posts: 536
Location: MB, Canada
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Quote: Originally Posted by '01 ZR2
go and gut your cats! i was getting 10 miles to the gallon and every thing on the truck was fine so i decided to check the cat and it was clogged, so i gutted it and i get 17-20 now, try it.
Quote: Originally Posted by '01 ZR2
its not the trany, thats what i thought it was doing the same thing yours was doing Tshak2000zr2 and it was the cat now every things all good.
In my experience, a plugged up cat usually results in a sudden extreme loss of power more-so than poor mileage. I am still willing to bet the OPs truck is not going into closed loop and since he did the t-stat along with everything else already, chances are it's the temp sensor.

OP - did changing your fuel filter make a difference? Also, if you haven't done a trans filter change, although it shouldn't effect this problem, it wouldn't hurt. Let us know how it goes
Old 12-19-2011, 11:21 PM   #29
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

my mechanic checked it out for codes and he said everything was reading perfect. I'm gunna calculate my mpg again and see if anything changed
Old 12-22-2011, 09:23 PM   #30
Registered User
 
Bow_Tied's Avatar
 
Join Date: Feb 2008
Posts: 62
Location:
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Another vote for t-stat. How old is it? I suggest replacing that and your rad cap.

Ideally this is the time for a coolant flush.
Old 12-27-2011, 03:30 PM   #31
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

The t-stat was replaced in October. I might flush the radiator soon and maybe trans fluid
Old 12-27-2011, 04:39 PM   #32
FIX BROKE STUFF
 
rustyg's Avatar
 
Age: 28
Join Date: Aug 2008
Posts: 536
Location: MB, Canada
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

How's your mpg been lately? Doing a coolant system flush/clean might help get the truck up to proper temp better, I suggest putting green fluid in afterwards but make sure you get it good and clean.
Old 12-29-2011, 08:51 PM   #33
Registered User
 
Zonk's Avatar
 
Age: 66
Join Date: Nov 2011
Posts: 56
Location:
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

I got my Ultragage and my first tank with it went from 14 to 18.5 just by watching the instant fuel mileage. Not bad for an 85 dollar add on. Hooking up behind a big rig on the freeway makes really big numbers. You can see it drop when you move to the side. It lets you find where your truck likes to cruise at and sip gas.
Bob
Old 12-29-2011, 10:36 PM   #34
goin broke but n style
 
S15vortecpwr's Avatar
 
Age: 33
Join Date: Jan 2007
Posts: 12,712
Location: Wetumpka, Alabama
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

if the OP only drives 4 miles 1 wy to scholl his truck never goes into closed loop. he will get sucky gas mileage.

I used to live 1 mile from my highschool. my 94 (stock) would avg about 5-8 mpg. on the hwy it got 22 mpg.

so unless he moves further away from school or changes school he will not get good mpg. he doesn't do enough hwy for the truck to offset the short trip.
Old 01-09-2012, 12:12 AM   #35
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

I just calc the mpg, and I'm averaging 13.5 mixed driving. Wish it was higher, but hey it's winter time in Cleve
Old 01-09-2012, 06:20 AM   #36
FIX BROKE STUFF
 
rustyg's Avatar
 
Age: 28
Join Date: Aug 2008
Posts: 536
Location: MB, Canada
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

That doesn't seem to far off normal, I average ~15 mixed driving.
Old 01-10-2012, 07:54 PM   #37
Registered User
 
iwillnc's Avatar
 
Age: 22
Join Date: Aug 2011
Posts: 250
Location:
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

You said you changed the spark plugs...

With AC Delco correct? I've never seen any other brand other than factory brand work in gm vehicles very well.
Old 01-10-2012, 07:57 PM   #38
Registered User
 
iwillnc's Avatar
 
Age: 22
Join Date: Aug 2011
Posts: 250
Location:
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Dang, 13.5 in that little truck?

I'm getting 11.7 in my H2, which has the 6.0
Old 01-11-2012, 01:37 PM   #39
Registered User
 
Join Date: Nov 2011
Posts: 13
Location: Cleveland, OH
User is: OffLine
Re: 2000 s10 zr2 poor fuel economy

Hey Zonk, so are u happy with the ultragage? I'm thinking about buying one if ur mpg increase is legit
Sponsored Links
Advertisement
 

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the S-10 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 06:43 AM.

Powered by vBulletin® Copyright ©2000 - 2011, Jelsoft Enterprises Ltd. SEO by vBSEO 3.2.0
SEO by vBSEO
vBulletin Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.