1988 454 belt

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

johnjr

Newbie
Joined
Jun 23, 2021
Messages
15
Reaction score
8
Location
NJ
Hi all, I just put new exhaust manifolds on my 88 3500 454. I want to take off the smog pump. I have been reading for hours and I have seen the posts about measuring with a string, but does anyone know the belt length or part number for the belt? Als, I saw where a guy on youtube did it on his 350 and just used a belt for no ac? I have ac by the way. Thanks
 

Schurkey

Supporting Member
Supporting Member
Joined
Jan 14, 2018
Messages
10,969
Reaction score
13,751
Location
The Seasonally Frozen Wastelands
1. WHY remove the AIR pump? What's the point?

2. There's likely a decal on the radiator support or fan shroud showing belt routing with/without the AIR pump. At least, the small-block trucks have that. Just go into a parts store, buy a belt for your vehicle "without" the AIR pump.
 

johnjr

Newbie
Joined
Jun 23, 2021
Messages
15
Reaction score
8
Location
NJ
1. WHY remove the AIR pump? What's the point?

2. There's likely a decal on the radiator support or fan shroud showing belt routing with/without the AIR pump. At least, the small-block trucks have that. Just go into a parts store, buy a belt for your vehicle "without" the AIR pump.
Because I had to ruin the air injector lines when I took the old ones off. The new ones came with plugs that I used. Why have a pump and a bunch of plumbing under the hood doing nothing, that’s why! And the belt choices are for air conditioning or no air.
 

someotherguy

I'm Awesome
Joined
Sep 28, 2013
Messages
9,799
Reaction score
14,162
Location
Houston TX
Because I had to ruin the air injector lines when I took the old ones off. The new ones came with plugs that I used. Why have a pump and a bunch of plumbing under the hood doing nothing, that’s why! And the belt choices are for air conditioning or no air.
Bump the year model up by 2 and check your options, compare part #'s to your year. A couple years after the GMT400s hit the streets, GM determined the AIR pump was not necessary to pass Fed emissions so it was eliminated. You'll see this reflected in the belt drive offerings for those years.

Richard
 

Schurkey

Supporting Member
Supporting Member
Joined
Jan 14, 2018
Messages
10,969
Reaction score
13,751
Location
The Seasonally Frozen Wastelands
Does this not affect the o2 readings?

FWIU, the A.I.R. Pump is only used when the engine is cold to help fire off the Cat. I don't think it is on when in Closed Loop.
Not a matter of "on" or "off". The pump runs whenever the belt turns (whenever the engine is running.)

With the small-blocks, there's a diverter valve that switches the air output from the exhaust manifold (engine cold--open loop when the O2 sensor reading doesn't matter--helping to light-off the catalyst) to the dirty side of the air filter in the air cleaner housing. At that point, the AIR pump is spinning and pumping air, but the output is useless.

I expect the big-blocks are the same. Haven't researched it.
 

johnjr

Newbie
Joined
Jun 23, 2021
Messages
15
Reaction score
8
Location
NJ
Just went on Rock Auto and looked up belt for ‘91. They have a listing for no air pump.(Thanks to someotherguy) Went on Amazon and ordered belt. Crossing myfingers it works.Thanks
 
Top