CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

AIS: Air Injection System on an '89 Chevy Suburban

I took my '89 Suburban in for emissions testing yesterday. The emission tech told me I should have an AIS (Air Injection System) pump. There is no AIS pump anywhere that I can see. The odd thing is that I’ve been driving the Suburban since it was new and have never been asked about the AIS. It’s marked as “N/A” on all previous emissions tests. Could this be one of those mid-year changes. The engine is the 5.7 litre (350 ci).

You probably don’t have one and never had one. If there are no tubes connecting to your exhaust manifolds, you probably don’t have the pump. There used to be one tube per cylinder when Chevy used them. The four on each side were joined into a connector that attached to a rubber hose.

Is your vehicle a P20? Yeah, I know, it’s a Suburban; but, most references will be by model number, not name. If you told the tester that your vehicle was a 350, that may have been misinterpreted as 7.4L, which does have an air pump. So, tell them that it’s a 5.7L, and that mistake won’t happen. Look at this guide, and you’ll see which ones had air pumps. You can click on your 5.7L Component Location guide, download the illustration, and show the tester.
{Later that day}: http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528006c592

The emissions stickers should mention it if it’s there. I think by '89 these were all fuel injected and I can’t recall ever seeing an AIR pump with a FI-ed engine.

My 87 was injected (TBI) and had no smog pump. It was a C-10 1/2 ton. Now if your Suburban is a C-20, 8500 pound GVW, they had different smog set-ups…These were the dark years for emissions controls…

The 2001 Chevrolet Venture minivan has an electric driven air pump, and it’s fully fuel injected. It has pipes to each exhaust manifold.