Check Engine Light

For some reason ( I believe it's vacuum ) the check engine light appears after starting the engine and applying the brakes... Cold or hot, doesn't matter. I can shut down the engine, and immediately restart, no check engine light. The engine does seem to pulsate if I push hard on the brakes however. I have checked the vacuum canister at the right front lower fender, and it seems to be holding fine, and pulls vacuum quickly. Is there somewhere else I should be looking, or do I just need to start replacing vacuum lines ?
1995 4L HO 4WD AW4

Have you checked to see if it's setting a code? You have OBDI, so it's key on, off, on, off, on again and read the flashing light sequence as two-digit numbers. Expect 55 for normal end of sequence, and probably 12 for recent battery disconnect (often appears anyway). Anything else is an actual fault code.

Pull the codes.

Could have a problem with the vacuum brake booster, why not start there?

joe_peters said:

Pull the codes.

Could have a problem with the vacuum brake booster, why not start there?

Click to expand...

Agreed; especially if the CEL is triggered specifically by braking. Will be interesting to see the stored code number(s).

If it stalls or bogs when braking, I'd concur that the booster is the first place to look. Remember that the brake uses its own reservoir, so it doesn't matter if the other canister and lines are all right.

It's not uncommon for the booster to leak where it joins the master cylinder. New booster if so. Make sure the check valve and associated lines are tight first.

As a preliminary check, run the engine and shut it down without using the brakes. Come back a few hours later and push the pedal. You should still have one or two pedal pushes with boost, and hear it sighing. If it's hard and no boost, you have a leak.

Thank's fellas.... The brake booster vacuum hose had a split on the bottom, out of sight. Replaced, and now the light, and the engine pulsations have ceased.
This forum has an incredible amount of knowledge that is truely appreciated by myself, and I am sure a host of others. This is my first experience owning an XJ, and I have seemed to have purchased one that has quite a few quirks, no real problems, actually, I enjoy spending my time "piddling" with it. Again , thank all of you for the advice, it makes this toy a pleasure to spend my time with.... Jabbo

COOKIE goes to Joe!

Glad you found the problem. Another happy forum ending.......!

Enjoy your '95.