International Full Size Jeep Association
Home Forums Reader's Rigs Tech Library Trail Stories FSJ-List
International Full Size Jeep Association  

Go Back   International Full Size Jeep Association > Tire Kickin' > General FSJ Tech

Reply
 
Thread Tools Search this Thread Display Modes
  #41  
Old 05-24-2022, 03:47 AM
Brynjminjones's Avatar
Brynjminjones Brynjminjones is offline
258 I6
 
Join Date: Jun 11, 2017
Location: Derby, England
Posts: 471
Another carb lover here too! I know they're not "better", but I feel like it suits the character of the vehicle better.

I don't think I'd enjoy driving it so much if it wasn't so stubborn at times
__________________
1991 Grand Wagoneer - Hunter Green. All stock. Rebuilt 360, .030" over with Melling MTA-1 cam.

1998 Cherokee (XJ) 4.0
1997 Grand Cherokee (ZJ) 4.0
1974 Ford F100 390
Reply With Quote
  #42  
Old 05-24-2022, 10:41 AM
rang-a-stang's Avatar
rang-a-stang rang-a-stang is offline
Administrator
 
Join Date: Oct 31, 2016
Location: Camarillo, CA
Posts: 4,691
Quote:
Originally Posted by Brynjminjones
...I don't think I'd enjoy driving it so much if it wasn't so stubborn at times
HAHAHAHAHAHAHA!!!!!!!
__________________
79 Cherokee Chief (SOLD, goodbye old buddy)
(Cherokee Build Thread)
11 Nissan Pathfinder Silver Edition 4x4
09 Mazdaspeed3 Grand Touring
00 Baby Cherokee
Reply With Quote
  #43  
Old 05-24-2022, 11:06 AM
devildog80's Avatar
devildog80 devildog80 is offline
232 I6
 
Join Date: Apr 13, 2022
Location: Apache Junction AZ
Posts: 201
Quote:
Originally Posted by Brynjminjones
Another carb lover here too! I know they're not "better", but I feel like it suits the character of the vehicle better.

I don't think I'd enjoy driving it so much if it wasn't so stubborn at times

Just the "nature" of our beasts
__________________
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving, than waiting for modifications!
Reply With Quote
  #44  
Old 05-25-2022, 09:33 AM
sierrablue's Avatar
sierrablue sierrablue is offline
232 I6
 
Join Date: Jan 24, 2022
Location: Northern MN
Posts: 108
Mostly I'm just too cheap for injection I wouldn't mind injection; the electronics don't care about sitting or the temp or anything. But here we are.

I am a little surprised that hooking up all of the emissions stuff helped mileage, but whatever works
__________________
Current Rig:
'71 Wagoneer (DD)
B350/TH400/D20
open knuckle D44 front (disc brakes)
6-lug conversion rear
http://www.ifsja.org/forums/vb/showt...79#post1734879

Previous Rig:
Tan '88 Grand Wagoneer
.030 over 401, TBI, headers
3" exhaust
31x10.5s
2" rear lift blocks
custom headliner
http://www.ifsja.org/forums/vb/showt...77#post1734777

"The engineering side of me says that it's more than strong enough. The redneck side of me says that it's going to fall apart and I need to beef it up."--somebody I know
Reply With Quote
  #45  
Old 05-25-2022, 04:26 PM
devildog80's Avatar
devildog80 devildog80 is offline
232 I6
 
Join Date: Apr 13, 2022
Location: Apache Junction AZ
Posts: 201
As designed they do not run too bad

Quote:
Originally Posted by sierrablue
Mostly I'm just too cheap for injection I wouldn't mind injection; the electronics don't care about sitting or the temp or anything. But here we are.

I am a little surprised that hooking up all of the emissions stuff helped mileage, but whatever works
__________________
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving, than waiting for modifications!
Reply With Quote
  #46  
Old 05-26-2022, 01:33 AM
Brynjminjones's Avatar
Brynjminjones Brynjminjones is offline
258 I6
 
Join Date: Jun 11, 2017
Location: Derby, England
Posts: 471
Quote:
Originally Posted by sierrablue
I am a little surprised that hooking up all of the emissions stuff helped mileage, but whatever works

I was surprised too! I think it was the EGR that made the difference for me. I figure that the carb was tuned to compensate for this, so enabling the EGR has probably brought me back to the right mixture when cruising. I have a delay valve on it that prevents it from coming in before about 10 seconds, so it doesn't cause any drivability issues either.

Sorting the charcoal canister and purge valve out fixed my hard hot starting too!
__________________
1991 Grand Wagoneer - Hunter Green. All stock. Rebuilt 360, .030" over with Melling MTA-1 cam.

1998 Cherokee (XJ) 4.0
1997 Grand Cherokee (ZJ) 4.0
1974 Ford F100 390
Reply With Quote
  #47  
Old 05-26-2022, 09:30 AM
devildog80's Avatar
devildog80 devildog80 is offline
232 I6
 
Join Date: Apr 13, 2022
Location: Apache Junction AZ
Posts: 201
Good to hear the beasts are happy and running good
__________________
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving, than waiting for modifications!
Reply With Quote
  #48  
Old 05-27-2022, 04:55 PM
sierrablue's Avatar
sierrablue sierrablue is offline
232 I6
 
Join Date: Jan 24, 2022
Location: Northern MN
Posts: 108
It always is

Just gave it more timing (it's at about 15 now; at 16 it started pinging on steep hills when it was warm), from 12. The power boost is definately noticeable (from what I've read, every degree gains you about 10 lb-ft of torque), and I can take off faster with the same amount of throttle. So that *should* help mileage a bit.
__________________
Current Rig:
'71 Wagoneer (DD)
B350/TH400/D20
open knuckle D44 front (disc brakes)
6-lug conversion rear
http://www.ifsja.org/forums/vb/showt...79#post1734879

Previous Rig:
Tan '88 Grand Wagoneer
.030 over 401, TBI, headers
3" exhaust
31x10.5s
2" rear lift blocks
custom headliner
http://www.ifsja.org/forums/vb/showt...77#post1734777

"The engineering side of me says that it's more than strong enough. The redneck side of me says that it's going to fall apart and I need to beef it up."--somebody I know
Reply With Quote
  #49  
Old 05-27-2022, 06:21 PM
devildog80's Avatar
devildog80 devildog80 is offline
232 I6
 
Join Date: Apr 13, 2022
Location: Apache Junction AZ
Posts: 201
Yes, more power should let you keep the pedal further away from the firewall, hence should not need as much gas to move the rig.
That is good news
__________________
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving, than waiting for modifications!
Reply With Quote
  #50  
Old 05-27-2022, 07:26 PM
sierrablue's Avatar
sierrablue sierrablue is offline
232 I6
 
Join Date: Jan 24, 2022
Location: Northern MN
Posts: 108
Quote:
Originally Posted by devildog80
Yes, more power should let you keep the pedal further away from the firewall, hence should not need as much gas to move the rig.
That is good news
Well, and last summer, advancing the timijg from about 3-5 up to 12 got me up to 13 mpg pretty consistently, and it didn't sound like a loaded up school bus anymore And now that I have a Qjet and another engine in it (that's in better shape)(and it has the stock Buick 4-barrel intake off a '70, which flows MUCH better than the stock 2-barrel manifold)...my in town mileage is like lower 14s, unless in town is exclusively what you're doing (which is not possible when you live 30 miles from a town with, well, much of anything). No smog equipment, but it's also designed not to have smog equipment, so that's probably why it runs so well without it. And the HEI distributor, while it's kind of ugly, gives me a nice hot spark, and allows like .045"-.050" plug gap. All of which improves power without requiring more fuel from the carb, thus gaining you fuel economy, right?

I do find it kind of amusing that people give me a hard time about my mileage, when the other full sized SUVs and trucks around are getting 8-13, and that's when they have overdrive and fuel injection...I realize weight, aero, and driving style play into it a lot, but still it kind of cracks me up.

Now if I get around to ordering and installing some new O-rings on the tank so that it doesn't leak slowly anymore, I may be in business.
__________________
Current Rig:
'71 Wagoneer (DD)
B350/TH400/D20
open knuckle D44 front (disc brakes)
6-lug conversion rear
http://www.ifsja.org/forums/vb/showt...79#post1734879

Previous Rig:
Tan '88 Grand Wagoneer
.030 over 401, TBI, headers
3" exhaust
31x10.5s
2" rear lift blocks
custom headliner
http://www.ifsja.org/forums/vb/showt...77#post1734777

"The engineering side of me says that it's more than strong enough. The redneck side of me says that it's going to fall apart and I need to beef it up."--somebody I know
Reply With Quote
  #51  
Old 05-29-2022, 08:08 AM
'89_Wagon '89_Wagon is offline
232 I6
 
Join Date: Jan 01, 2019
Location: New Hampshire
Posts: 143
AAA published a cost of ownership study on different types of cars and IIRC, the biggest chunk is depreciation... not gas. Now, this study was done on new vehicles. I'm sure this year's study will increase the gas part, but depreciation on an SUV is about $4k a year and gas was $1500 a year at $2.36 a gallon.... oh wow.... I'm just realizing with gas prices as high as they are gas may overtake depreciation for biggest ownership costs. That sucks.


https://newsroom.aaa.com/wp-content/...chure-Live.pdf
__________________
'89 Grand Wagoneer
AW4 Swap
Reply With Quote
  #52  
Old 05-29-2022, 08:49 AM
sierrablue's Avatar
sierrablue sierrablue is offline
232 I6
 
Join Date: Jan 24, 2022
Location: Northern MN
Posts: 108
Quote:
Originally Posted by '89_Wagon
oh wow.... I'm just realizing with gas prices as high as they are gas may overtake depreciation for biggest ownership costs. That sucks.


https://newsroom.aaa.com/wp-content/...chure-Live.pdf
Time to get the mountain bikes greased up and get back into shape
__________________
Current Rig:
'71 Wagoneer (DD)
B350/TH400/D20
open knuckle D44 front (disc brakes)
6-lug conversion rear
http://www.ifsja.org/forums/vb/showt...79#post1734879

Previous Rig:
Tan '88 Grand Wagoneer
.030 over 401, TBI, headers
3" exhaust
31x10.5s
2" rear lift blocks
custom headliner
http://www.ifsja.org/forums/vb/showt...77#post1734777

"The engineering side of me says that it's more than strong enough. The redneck side of me says that it's going to fall apart and I need to beef it up."--somebody I know
Reply With Quote
  #53  
Old 05-29-2022, 11:29 AM
devildog80's Avatar
devildog80 devildog80 is offline
232 I6
 
Join Date: Apr 13, 2022
Location: Apache Junction AZ
Posts: 201
Little bike trailer on the back for hauling stuff back 30 miles from "town"
__________________
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving, than waiting for modifications!
Reply With Quote
  #54  
Old 05-29-2022, 12:15 PM
sierrablue's Avatar
sierrablue sierrablue is offline
232 I6
 
Join Date: Jan 24, 2022
Location: Northern MN
Posts: 108
Quote:
Originally Posted by devildog80
Little bike trailer on the back for hauling stuff back 30 miles from "town"
Exactly!

The funny part is I actually have all of the stuff to do that...only thing is 60 mi/ day (without in town riding) gets to be a lot, especially on a mountain bike, with a load. Not to mention it takes all day...
__________________
Current Rig:
'71 Wagoneer (DD)
B350/TH400/D20
open knuckle D44 front (disc brakes)
6-lug conversion rear
http://www.ifsja.org/forums/vb/showt...79#post1734879

Previous Rig:
Tan '88 Grand Wagoneer
.030 over 401, TBI, headers
3" exhaust
31x10.5s
2" rear lift blocks
custom headliner
http://www.ifsja.org/forums/vb/showt...77#post1734777

"The engineering side of me says that it's more than strong enough. The redneck side of me says that it's going to fall apart and I need to beef it up."--somebody I know
Reply With Quote
  #55  
Old 05-29-2022, 02:59 PM
devildog80's Avatar
devildog80 devildog80 is offline
232 I6
 
Join Date: Apr 13, 2022
Location: Apache Junction AZ
Posts: 201
Might need to get you a tent to take with, in case of overnight required
__________________
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving, than waiting for modifications!
Reply With Quote
  #56  
Old 06-03-2022, 06:33 PM
johnsonic johnsonic is offline
258 I6
 
Join Date: Mar 12, 2015
Location: Oregon
Posts: 295
On a recent 2,000 mile trip, 65-70 MPH (hovering around 3,000 RPM) I was getting 14MPG.

Around town I get about 6-8MPG. I'm mostly around town driving nowadays and with an aux tank a fill-up runs around $280 with clear gas.

I'm running 235/75/r15s with a 3.31 differential, 727 transmission. Motor is bored .030, comp 260h, wiseco -21cc forged pistons, Harland rollers. MSD HEI. Holley SA 670, Performer manifold, motor emissions delete (though still blow way cleaner than regulation - I don't want to injure the environment, just want to have an efficient vehicle, fewer fumes more fun or same fumes more fun). High flow cat, no air pump. 3" BJ's stainless exhaust.

I need to write all of that to make the money spent feel worth it! I do think that how easy it is to spin my crankshaft with the rollers and lesser mass of the rotating assembly makes a difference, but I don't know what I'm talking about.

My carb is way too big, and would probably want one with smaller primaries - anyone know if that would help around town? Also doubting manifold vacuum for in town driving. Would like to avoid the FI route.
__________________
1984 GW
360
Comp 260H
Harland Sharp Roller Rockers
Wiseco -21cc Forged Pistons
Performer Intake
Holley SA 670
MSD 8523
Dakota Digital custom cluster
Serehill headlamp harness
NWMP aux tank

1987 GW deceased
...but the parts live on
Reply With Quote
  #57  
Old 06-03-2022, 06:49 PM
devildog80's Avatar
devildog80 devildog80 is offline
232 I6
 
Join Date: Apr 13, 2022
Location: Apache Junction AZ
Posts: 201
Keep your base engine as is

Change carb to Quadrajet (smaller primaries)

Put emissions back on engine

Reduce exhaust size to spec (2 or 2-1/4) as you need more back pressure, not more flow

Should bring your in town mpg up over 10, and push your hiway up a little more

Might be right....might be wrong....just my $.02
__________________
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving, than waiting for modifications!
Reply With Quote
  #58  
Old 06-03-2022, 07:34 PM
sierrablue's Avatar
sierrablue sierrablue is offline
232 I6
 
Join Date: Jan 24, 2022
Location: Northern MN
Posts: 108
Ditto on the Quadrajet. The Edelbrocks aren't too bad either--but they are square bore and have bigger primaries than the Qjet will. But they both have metering rods, and will do about the best you can get w/o switching to FI, when tuned right.

If you want to run it with stock stuff (which it doesn't sound like is an issue for you), then yes, I agree that the emissions stuff will help. But if you're willing to do some tuning (jets, metering rods, timing, etc.)(Edelbrock sells really good tuning kits for both the 1406 and the Qjet, so you can make pretty much anything run really well on those carbs, if you take a little time).

Basically on a lot of engines, the key to get every last bit of mileage out of them is to tune them to make maximum power (w/o requiring more gas, i.e. usually don't change the fuel system itself), but then to not use that power. A vacuum gauge will help you to see how to change your driving to accomodate for this. As far as low vacuum at low throttle, big cams tend to cause that. But a big cam shouldn't hurt mileage because it still takes the same amount of fuel and air to move it at whatever speed you're going; the cam doesn't change the cubic inches or anything.

It sounds like you have a lot of good bits on it--the intake and exhaust should give you some nice flow, which is always good. In my experience, as long as the exhaust isn't really restricting anything, it should be fine, regardless of back pressure. The '88 had 3", cat and muffler, headers, with TBI on the .060" over 401, and would get like 15 regularly. The '71, while it has the stock 2" y-pipe (actually it's more of a t-pipe...), that goes into 2.5", which goes into 3" (which is excessive for a 350, I'll grant you), and it'll get 15 regularly, which may drop down to 13-14 if there's A LOT of idling around and bad town traffic (this is in 2, on summer gas).

Another thing you might consider is the stock heat riser tube, making the air drawn into the engine a little warmer. Or if not the riser, at least a non-open element or cold air intake; that will help with mileage some.

Just my .02 also; this is what seems to be working for me. A lot of it is driving style, for sure though.
__________________
Current Rig:
'71 Wagoneer (DD)
B350/TH400/D20
open knuckle D44 front (disc brakes)
6-lug conversion rear
http://www.ifsja.org/forums/vb/showt...79#post1734879

Previous Rig:
Tan '88 Grand Wagoneer
.030 over 401, TBI, headers
3" exhaust
31x10.5s
2" rear lift blocks
custom headliner
http://www.ifsja.org/forums/vb/showt...77#post1734777

"The engineering side of me says that it's more than strong enough. The redneck side of me says that it's going to fall apart and I need to beef it up."--somebody I know
Reply With Quote
  #59  
Old 06-03-2022, 07:48 PM
devildog80's Avatar
devildog80 devildog80 is offline
232 I6
 
Join Date: Apr 13, 2022
Location: Apache Junction AZ
Posts: 201
But.....I have never read anything across 3 different Jeep sites where FI gets you any more mileage than a carb does.

Just gives you the turn key and go like newer vehicles, without the usual warm up required with a carb.

The key is to have everything adjusted and tuned properly, no matter what type of fuel delivery you have.
__________________
1984 Grand Wagoneer, 401 ci (.030 over), A727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT (6 LUG) WT 3.31, 4 in arch spring lift (not a woody - think it was ordered new without, 1984 the only year it was an option)
Rather be driving, than waiting for modifications!
Reply With Quote
  #60  
Old 06-03-2022, 08:05 PM
sierrablue's Avatar
sierrablue sierrablue is offline
232 I6
 
Join Date: Jan 24, 2022
Location: Northern MN
Posts: 108
Quote:
Originally Posted by devildog80
But.....I have never read anything across 3 different Jeep sites where FI gets you any more mileage than a carb does.

Just gives you the turn key and go like newer vehicles, without the usual warm up required with a carb.

The key is to have everything adjusted and tuned properly, no matter what type of fuel delivery you have.
True. But there are two-three key other areas where fuel injection has the edge. Number one, temp and humidity changes do are accounted for with injection, because it has the O2 sensors to adjust the mixture. Because vacuum isn't really affected (especially not by humidity), carburetors do not account for it. Number two, FI allows for altitude changes w/o changing the timing or anything...and if you have a mass-air style system (which I don't think any of the TBI units have, and even the Chrysler injected 4.0s won't have it), mileage doesn't jump when you go up in altitude; it gets that great mileage like it would at higher altitude all of the time. The other key thing is that the electronics don't care about time or anything; there's nothing to be mechanically changed. So if it sits a lot, or gets driven in harsh conditions a lot, there's another bonus. Or even if it gets driven daily, every once in a while you get something through the fuel filter and it makes the needle stick...

Now that's not to say that a well-tuned carb won't keep up pretty well, and metering rods help a lot with altitude, as altitude DOES affect vacuum. But for consistancy and very slight little gains in economy, injection is absolutely the way to go.
__________________
Current Rig:
'71 Wagoneer (DD)
B350/TH400/D20
open knuckle D44 front (disc brakes)
6-lug conversion rear
http://www.ifsja.org/forums/vb/showt...79#post1734879

Previous Rig:
Tan '88 Grand Wagoneer
.030 over 401, TBI, headers
3" exhaust
31x10.5s
2" rear lift blocks
custom headliner
http://www.ifsja.org/forums/vb/showt...77#post1734777

"The engineering side of me says that it's more than strong enough. The redneck side of me says that it's going to fall apart and I need to beef it up."--somebody I know
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
42 Gallon Suburban Fuel Tank Installation (With more Pics!!!) Wagoneerlover General FSJ Tech 42 09-14-2010 08:34 PM
fuel problem... gladman General FSJ Tech 10 02-11-2010 02:34 AM
fuel pump stalling issues westcoastflea General FSJ Tech 8 07-21-2009 08:40 AM
Has anyone ever installed an in-line fuel pump? ultimatejb General FSJ Tech 4 08-20-2008 06:56 AM
Upgrades/Tweaks to Improve MPG prayforsurf General FSJ Tech 33 01-04-2007 10:39 PM


All times are GMT -6. The time now is 10:03 AM.


Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
corner corner