How she runs...

[SilverSHO]

I've got most of the major stuff on my SHO fixed; however, I can't figure out the pathetic gas mileage. I get around 200/220 miles on a full tank. The car seems a bit down on power, although much better than before I replaced the DIS module. When accelerating under steady throttle, it surges and bucks a lot. Exhaust smells strongly of gas, and backfires constantly (most likely due to hollowed cats and leaks near the mufflers). It idles fine without smoking, but when revved kicks out a lot of smoke. No CEL whatsoever, so I don't know if the O2 sensors are responsible for the bad gas mileage.

KOEO codes are kosher; gave me Continuous Memory codes 49 and 95. I haven't run the KOER yet, but I plan to in the near future. I'm just trying to pin down the source of my horrendous gas mileage. Any ideas?

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Nick
Lt. Titanium 90 135k
Coneless, ACCEL 8.8 stainless steel wires,
SHO Shop torque limiters, Cherry Bomb Turbo II mufflers (sound pretty damn good for $15 mufflers )
New to the family: '73 VW Beetle...MUCH less expensive to mod than the SHO, but somehow not quite as much fun
AIM: loudog6491

 

[smp321_98]

I'm not sure about your problem, but I am wondering what effect hollowing out the cats had on your performance? I am thinking of doing the same thing!!

 

[SilverSHO]

You lose a little low-end torque, but gain a little more high-end power because of the lessened restriction. The only reason I did it is because they were clogged and getting red hot when I ran the car for more than a few minutes.

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Nick
Lt. Titanium 90 135k
Coneless, ACCEL 8.8 stainless steel wires,
SHO Shop torque limiters, Cherry Bomb Turbo II mufflers
AIM: loudog6491

 

[RStalveyARFF]

have you checked to see if there is oil in your plug wells? Your problems seem to be consistent with a misfire.

 

[sdpatt]

You are low on power and getting poor gas mileage because your ignition timing is defaulted to 10 degrees BTDC. Your code 49 gives you that information: "SPOUT signal defaulted to 10 degrees BTDC; SPOUT ciruit open."

There is an unclipped connector or a discontinuous wire in the SPark OUTput system. I have not had specific experience with this failure (knock on wood) so I can't get any more specific at this time. I have posted the question on the LSSHOC list. I will provide the response here if I receive one that may explain this code.


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Scott

1991, 252K miles, glass hood, police grill, SVO shifter, Catz fogs,
K&N, 73mm MAF, Superchip, PP Y-pipe, Borla cat-back, 190 lph pump
Eibach/Tokico/polyurethane, SHO Shop front & rear strut braces,
16x7.5" Moda R1, 225/55ZR16 Bridgestone RE730, -1 deg camber x 4,
Class II hitch, Silver award at the SHOklahoma Car Show

 

[SilverSHO]

Thanks, Scott. I knew the 49 had something to do with the SPOUT circuit, but I couldn't remember what.

I do know, however, that there IS a female connector on the back side of my motor that's not plugged in to anything; it's gray and has an oval-shaped plug surrounded by a rectangular clip. It's on the end of the head next to the #3 cylinder, right next to the valve cover, kind of under and behind the throttle body. I don't know if it's the SPOUT connector, but something tells me it should be plugged in to something.

 

[SilverSHO]

:kick: to the top...

 

[SLOSHO89]

Originally posted by SilverSHO:
I do know, however, that there IS a female connector on the back side of my motor that's not plugged in to anything.

Is it part of the wiring harness?

If it is what I'm thinking it is,....It should be plugged into a black box.

The box has a tube which should be connected to the tube (by a short black vacume tube) that goes from the EGR Valve to the rear intake manifold. That is what mine does....it is a CA car though so it might have a different smog setup.

I think the black box measures the amount of vacume. It is related to the smog system though!

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Oxford White '89 SHO
Slicers, SHO+ hood and spoiler, Met.-Red and Gold Intake.

Web Page www.geocities.com/web_page66/

 

[Prophet78]

That is about the same gas mileage I get, actually depending on how I drive I can get 250 MPT (Miles per Tank). Then again I never let my car get past the 1/8 tank mark. That is where I fill it up.

My guess is that you aren't getting the back pressure you used to because your cats are hallowed. Also, the job of the cats is to clean the exaust and combust any gas that hasn't done so already. That may be the reason you are smelling gas. I would get your exhaust looked at. If you have leaks that isn't good. The SHO engine needs to scavange for HP.

If you have a connector that is supposed to be connected but its not, I would get that checked too.

-Jeremy-

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'93 Red ATX "Red Phoenix"
Rebuilt "Ford Quality Rebuilt Transmission" w/ Shift Kit
190 LPH Fuel Pump
Koni Inserts
Eibach Springs
Blazer Modded Fog Lights
Taylor 8mm Spiro Wires
K&N Air Filter
SHO Filler decals
Fish Tanks
225/50/16 BFG GeForce T/A KDWS