Gas guzzling THIS MUCH???? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 02-08-2004, 10:27 PM
New Member
 
Join Date: Dec 2003
Location: northwest
Posts: 20
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Gas guzzling THIS MUCH????

Sorry, back again with a consistent problem.

** Note: 85 chevy s-10 V6 2.8L 4x4, carbureted.
Every tune up part has been completed (with exception to replacing the egr valve). Rochester 2se Carb rebuild. S-10 is "running" great...except... **

Ok, this S-10 is driving so much better...but I'm not getting the "proper" MPG still (proper for this year gas hog that is). Something else is going on with this carb.
Notes: The idle in park = 850-900rpm, idle in drive = 650-700rpm (this is the ideal idle speed for these vehicles I am told).
It's ABSOLUTELY CHUGGING GAS beyond normalcy for these gas hogs (to me that is).

Latest example:
I took my s-10 up skiing - keeping to the speed limits. From a full tank (15 gallon tank) I drove approx 85.53 miles (2 hours, 11min drive).
I am now at a little less to in-between 1/4 tank now. ;(
Stupid me, I didn't note a starting milelage # so I am giving this rough estimate this way.
85.53 miles DIVIDED by 15 (15 gallon tank) = 5.702 (5.7 mpg). Whaaaaa???

Would this rough calculation above work or am I doing this way wrong ?
If correct...5.7 mpg??????????? #%$$%#$%$%$#$!!

Let's say it only ate 12 gallons of a full 15 gallon tank. That would still be 7.1 mpg !!! (85.53 divided by 12)
Christ! I know trucks are bad, but THIS bad?

Check this out, is this a clue as to the problem?
I remember after wrapping up everything, I was setting the idle speed. The truck was warmed up..
I remember backing off the idle screw (phillips head) all the way out (totally out). It SHOULD have just died right there I assumed but it didn't.
After idle was totally backed out, it was still constantly idling (roughly and poorly) at 450-500 rpm.
Kinda bouncy between the two on my rpm tach.

So...
should this s-10 come to a complete stall with the idle screw backed out all the way?
Or is this normal for the vehicle to do this?
If not normal, I'm now suspecting my throttle plates are screwed up (or the throttle plate bushings are so worn, it's leaking fuel pretty bad.
If THIS IS NORMAL....then I don't know what is wrong BUT DO KNOW I CAN'T KEEP IT WITH THAT PISS POOR OF MILEAGE for a 2nd vehicle.

Any ideas people? This should be carb related I would think, cause every tune up on the checklist has been completed (with exception to the egr valve now mentioned...hmmmm).
Would the egr cause THIS BAD OF MPG? Maybe, this I don't know.

Is my calculation of my MPG in the example wrong (I hope, I hope)?

Could too high (or too low) a float level be the cause? It seems to operate great and I set the float level as per spec (5\32" from top of float to gasket level with float fully seated).
I was also suspecting the linkage, but I havn't touched that. What part of linkage would equate to this and what\how should it be adjusted?

Keep in mind, I'm not blowing black smoke any longer at cold start, all cycls are firing now, idle is great and in spec, runs so much better than when I first got it to rescue it. Seems to be running as per spec It's just "drinking" gas so much (if my calc above IS correct that is).

Could really use your help, as now I'm hooked on solving this (why?...who the hell knows. I'm nuts).


JD
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-09-2004, 08:42 AM
willys36@aol.com's Avatar
Hotrodders.com Moderator
 
Last wiki edit: How to rebuild a Rochester Quadrajet 4MV carbureto...
Last journal entry: How to change auto shift timing on 200R4
Last photo:
Join Date: May 2002
Location: Bakersfield
Posts: 8,372
Wiki Edits: 21

Thanks: 1
Thanked 3 Times in 3 Posts
Your numbers and description of performance don't make sense. Check the mileage accurately by recording actual miles driven and actual gas used to top off the tank - gas gages are notoriously inaccurate. If you were truly using that much gas, your plugs would be fouled within a few 100s of miles you would be emitting discernible black smoke, and the car would be very hard to keep running. Do your plugs read dark brown or fluffy black? They should if you are pouring that much gas thru it. If they are white or of white, my guess is that your calculations are in error.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-09-2004, 08:55 AM
Jag Daddy's Avatar
British Style with USA Muscle
 
Last photo:
Join Date: Mar 2003
Location: Valencia, California
Age: 57
Posts: 1,070
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
85.53 miles DIVIDED by 15 (15 gallon tank) = 5.702 (5.7 mpg)
First your calculation is off

You did not run the tank dry so you didn't use all 15 gallons. 3/4 of 15 is 11.25, so divide 85.53 by 11.25 and you get almost 8 mpg.

Next you said you went skiing, going up hill and with high altitude you mileage will go down.

I agree with willies (as usual) you would see belching black smoke out the tailpipe if it were chugging gas. I think your tailpipe would be also covered inside with black soot.

Regards
Mark
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-09-2004, 09:41 AM
poncho62's Avatar
Out of the Loop Moderator
 
Last wiki edit: Streetbeasts links
Last journal entry: at car show
Last photo:
Join Date: Oct 2003
Location: Hanover, Ontario, Canada
Age: 61
Posts: 16,789
Wiki Edits: 5

Thanks: 19
Thanked 237 Times in 193 Posts
Hey joe99..........I know your grief. My 83 4X4 2.8 piece of crap Blazer is a real hog on gas too. Especially this time of year when it is colder out. Last week, I used $45 in gas just driving around town. Granted, I did a bit of snowplowing with it, but you can almost see the guage go down.

Funny thing though. Yesterday, I took it up to my trailer, which is about a 120 mile round trip and it only used about $20 of gas. Gas here in Canada is about $3.25/gal, so thats about 6 gallons. That works out to 20 mpg. Those were highway miles.

Around town is another thing, I'd be suprised if I am getting half that.
__________________
Ontario Rodders
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-09-2004, 11:17 AM
New Member
 
Join Date: Dec 2003
Location: northwest
Posts: 20
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I understand the rough calculation error, but even at 11 gallons (near 1/4 tank left, that would still be horrid gas mileage.
I just don't remeber it ever being this bad.

Update, i now need to add to this that I am smelling a strong gas odor when idling. It was suggested on another s-10 forum that my float level (although I thought is set to fac spec) might be off (I assume being too "high of level").

I am going to set the float a little lower and see what happens then.

what do you think about the idle issue (turning it all the way out yet it still idles around 450-500)?
Could this be my throttle plates or bushings for them?
Or is this normal?

thanks,
JD
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-09-2004, 01:15 PM
Jag Daddy's Avatar
British Style with USA Muscle
 
Last photo:
Join Date: Mar 2003
Location: Valencia, California
Age: 57
Posts: 1,070
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Well something isn't quite adding up here. You need to pull a plug and look at it. The funny thing is I've seen cars running rich and you can usually see them blowing black smoke even at idle.

Does it backfire in the tail pipe? With that much unspent fuel I would think it would be making all kind of noises. Have you checked you oil as well to see if it's got gas in it? Maybe you've lost the intake gasket?

This may be a dumb question have you checked your choke assm. to make sure it's opening up at temp?

Just some thoughts
Good luck
Mark

Last edited by Jag Daddy; 02-09-2004 at 01:20 PM.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 02-09-2004, 02:26 PM
New Member
 
Join Date: Dec 2003
Location: northwest
Posts: 20
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Plugs seem to show normal burning (kind of a tan color to them) but i will definitley check again after another short drive.

It used to backfire when I had all the past problems I've addressed:
- ignition post was broken by last tech causing horrid starting.
- vaccum lines deteriorated (replaced all of them).
- vaccum diaphrams on rochester 2se carb were not working causing the choke to stay fully closed until warm, i replaced both and now it fires up beautifully.
- choke does open as it should when warm
- new sparks and cables, firing great.
- checked oil and don't see\smell signs of gas in it - nor coolant.
just regular burning oil.

Like i said, everything tuning wise is great now...but it's guzzling gas more than it really should.
I do have a little exhaust leak at the exhaust manifold but that shouldn't be related, should it?

what about that throttle plate or it's bushings? Did the above sound normal to you guys (still idles even when idle screw is completely backed out)?

I don't see how my gas mileage test is that inaccurate really?
It's on the same tank of gas (15 gallon tank filled full, went 85 miles\2hour trip to and from - again, same tank of gas, when I arrived back it is at exactly 1/4 tank.
Now this may not be that bad of gas mileage, I'm thinking it is but I want to run it by you guys.

thanks for helping, I really want to nail this problem,
Jd

Last edited by joe99; 02-09-2004 at 03:14 PM.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 02-09-2004, 03:42 PM
Tazz
 
Last photo:
Join Date: Jun 2001
Location: amherst,ohio
Age: 65
Posts: 2,049
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
CK gas milage?

Fill up your tank,let the machine shut off the pump and reset the trip odometer or write down the milage. Drive someplace, put 30 to 50 miles and go to the same station and use the same pump and fill up the tank again letting the pump shut itself off. Use those numbers to CK your milage and consumption. You don't need to run a tank of gas out to CK the gas milage, only 30 to 50 miles of driving are enough maybe even less.


Tazz


Rat Rods Rule!
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last 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 for yourself.
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.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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 -6. The time now is 04:40 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.