Hey everyone, I have a 1991 XJ40 and recently removed the air pump from my car. To be clear I removed the air pump, air pump belt, and the hose that connects the air filter box to the air pump. Everything else was untouched, So after the air pump there's some sort of valve with a vacuum line connected to it, and the vacuum line goes to this light blue part, and another hose that goes from the air pump to the engine block I believe, I left those intact and didn't plug them or anything.

Before removing the air pump my car started normally/instantly ~2 seconds when turning the key but now with the air pump removed the car takes much longer to start ~7 seconds and sometimes doesn't start on the first try, it will start normally on the second attempt though.

Can someone help me remedy this issue, should I reinstall the air pump? I don't want to and from what I read doesn't do much. Should I plug the holes that were left behind from removing the air pump? Should I remove the additional parts?

Car seems to run a little better/no different compared to when it was running with the air pump installed. Only issue im having is the starting issue

Empty space where the air pump use to go, and goldish valve that connected to the air pump

vacuum line going to the blue part, are these parts needed?

 

Hi Stran0020,

You can learn about the operation of the secondary air injection system on pdf page 32 of this manual:

Jaguar AJ6 4.0L Engine Management System / OBDI Diagnostic Guide

The blue solenoid valve is connected directly to intake manifold vacuum and the pump is connected directly to the exhaust, so in essence, by removing the pump you have created a cold-start vacuum leak. The SAI system is designed to run until the coolant reaches 95°F or engine rpm reaches 2,500 rpm (which, of course, it should not do while cold).

It would certainly be worth plugging/capping the hoses to see if your cold start issue is resolved.

Cheers,

Don