Smog Pump bypass. Belt/Tensioner/Pullies???

stangposse · 08-28-2004, 10:31 AM

It seems like my smog pump has failed. Sounds like marbles in a can.

So until I can remove/replace it, I have decided to get a shorter belt and bypass it so my car sounds normal again.

I've been told that to bypass the smog pump I would need a 84.5" belt. So thats what I bought. The belt is loose, flapping around and squeals just off idle. It's installed correctly.

Can my tensioner be shot??

Did I buy the wrong size belt??

Is the 84.5" belt too long for underdrive pulleys??

I have A/C and PS still installed.

Thanks for your help.

93 LX 5.0

stang_racer20 · 08-28-2004, 11:40 AM

Where does your tensioner arrow sit at? There is a range on the tensioner.

ols0051 · 08-28-2004, 03:47 PM

Go to the parts store and get a shorter belt until if fits correctly. I'm using a 69inch belt with the a/c removed. I had to return belts about 6 times before I was able to get it right. I have a spare smog pump pm me and I'll make you a deal you can't refuse.

poonstang90lx · 08-29-2004, 03:29 PM

does the car have under drive pulleys if not go with a 76 or 77 inch belt

gmhatr · 08-29-2004, 07:06 PM

dont guess just taks a piece of string and go around and measure it. It's that simple.

88fivepointoh · 08-30-2004, 01:10 PM

i agree with the string methode. Works everytime.. also Maybe your better off getting a new pump. depending in how your motor is running, it may run crappy after you remove it.

poonstang90lx · 08-31-2004, 02:18 AM

Dont worry about replacing the pump, I have never had a problem bypassing the pump and I have had 8 different EFI fox body cars. The thing just sucks horsepower bypass it if there is no smog check in your area. You never said if it had under drive pulleys or not .

stangposse · 08-31-2004, 07:38 AM

Thanks guys.

I have the underdrives on the alt, crank and w/p.

My tensioner is pegged so I assume the belt I have is longer than I asked for or the 84.5" measurement I was told was way off. I'll run a string around it and see what I get.

Whatever number I get from my measurement, should I get the belt an inch or two longer so I can get it around all the pullies before the tensioner goes down on it???

08-28-2004, 10:31 AM	#1
stangposse Registered Member Join Date: May 2002 Location: Connecticut Posts: 12	Smog Pump bypass. Belt/Tensioner/Pullies??? It seems like my smog pump has failed. Sounds like marbles in a can. So until I can remove/replace it, I have decided to get a shorter belt and bypass it so my car sounds normal again. I've been told that to bypass the smog pump I would need a 84.5" belt. So thats what I bought. The belt is loose, flapping around and squeals just off idle. It's installed correctly. Can my tensioner be shot?? Did I buy the wrong size belt?? Is the 84.5" belt too long for underdrive pulleys?? I have A/C and PS still installed. Thanks for your help. 93 LX 5.0

08-28-2004, 11:40 AM	#2
stang_racer20 Registered Member Join Date: Jun 2003 Location: Wisconsin Posts: 348	Where does your tensioner arrow sit at? There is a range on the tensioner. __________________ 92 Mustang GT, 347 Stroker(Forged Steel Crank/Rods-Balanced, Forged Aluminum Dished Pistons), Trick Flow Track Heat Intake, Trick Flow Twisted Wedge Heads w/ Stage 3 port/polish, 80mm C&L MAF, FMS 30# Inj., BBK AFPR, Trick Flow Stage 2 Cam, Trick Flow 1.6R Rockers, BBK E.L. Headers, Flowmaster Cat-Back, MAC CAI, FMS Pulleys, Griffin Alum. Radiator, MSD Pro-Billet Distributor; AOD, Dynamic 3300 Lockup Converter, B & M Super Cooler, B&M Ratchet Shifter; 3:73 gears.

08-29-2004, 03:29 PM	#4
poonstang90lx Registered Member Join Date: Aug 2004 Posts: 10	does the car have under drive pulleys if not go with a 76 or 77 inch belt __________________ 90lx 331 5spd holley systemax kit 3.55 gears

08-31-2004, 02:18 AM	#7
poonstang90lx Registered Member Join Date: Aug 2004 Posts: 10	Dont worry about replacing the pump, I have never had a problem bypassing the pump and I have had 8 different EFI fox body cars. The thing just sucks horsepower bypass it if there is no smog check in your area. You never said if it had under drive pulleys or not . __________________ 90lx 331 5spd holley systemax kit 3.55 gears

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
smog pump delete	89droptop	Windsor Power	11	03-15-2010 04:01 PM
Smog Pump Deletion	92MUFDVR	Windsor Power	7	07-14-2003 11:05 AM
Smog Pump Confusion	Evil Joe	Windsor Power	1	03-23-2003 08:04 AM
SN95 Smog Pump Drama	Mustangbelle306	Windsor Power	5	02-27-2002 01:02 AM
PLEASE HELP!! Do I need the smog pump system to pass dyno emissions ??	Stang_ROTY	Windsor Power	5	07-02-2001 01:09 AM

08-28-2004, 03:47 PM	#3
ols0051 Registered Member Join Date: Sep 2002 Location: cent.wis Posts: 203	Go to the parts store and get a shorter belt until if fits correctly. I'm using a 69inch belt with the a/c removed. I had to return belts about 6 times before I was able to get it right. I have a spare smog pump pm me and I'll make you a deal you can't refuse.

08-29-2004, 07:06 PM	#5
gmhatr Registered Member Join Date: May 2004 Location: Mattoon IL. Posts: 91	dont guess just taks a piece of string and go around and measure it. It's that simple.

08-30-2004, 01:10 PM	#6
88fivepointoh Registered Member Join Date: Aug 2002 Location: Rochester Posts: 553	i agree with the string methode. Works everytime.. also Maybe your better off getting a new pump. depending in how your motor is running, it may run crappy after you remove it.

08-31-2004, 07:38 AM	#8
stangposse Registered Member Join Date: May 2002 Location: Connecticut Posts: 12	Thanks guys. I have the underdrives on the alt, crank and w/p. My tensioner is pegged so I assume the belt I have is longer than I asked for or the 84.5" measurement I was told was way off. I'll run a string around it and see what I get. Whatever number I get from my measurement, should I get the belt an inch or two longer so I can get it around all the pullies before the tensioner goes down on it???