XJ Madness99

Got in my 1999 xj and when i started it missed a little when i gave it gas it went away. However when i went to leave and merge on the highway it seamed to lose a lot of power. Didn't notice a miss but definitely a lose of power. Does any have any ideas as to where to start looking to remedy this?

tjwalker

First off, any check engine light? If so, you must pull codes for clues/guidance.

1. Review status of tuneup hardware. When was the last time you installed fresh plugs, quality plug wires, distributor cap and rotor? Importance of this hardware cannot be overstated.

2. Test your fuel pressure. For a 99, you should have 49 psi, plus or minus 5 psi. If you don't have access to a gauge, call around to parts stores to see if one will rent you one.

XJ Madness99

No Codes and a tune up was done rite before i bought the xj 1 year ago.

IJM

Does the problem go away at full throttle?

cruiser54

What kind of tuneup?

Plugs, wires, cap and rotor are a tuneup every 30,000 miles.

Look inside the distributor cap and inspect the wires.

XJ Madness99

No the problem persist at full throttle and it was a cap wires plugs and flush. Everything looks fine inside the cap and I can’t see any cracks on the wires. I also waited until dark and looked to see if they where jumping fire any where. They weren’t. Still no codes to. And the miss has gone away

cruiser54

Lucky you.

fb97xj1

XJs like to throw tantrums every now and then. I think they do it for attention.

XJ Madness99

Not really lucky the miss went away but the loss of power is still there

XJ Madness99

ok got it done today it was fuel pump. went ahead and change the o2 sensors while i was in there.

97grand4.0

great! glad we figured it out for you.

XJ Madness99

me to thank you all.

PatHenry

In all seriousness, thank you for posting the resolution. Too many threads drop off without a clear answer to the original problem.