Has anyone here noticed after fab'ing/installing new modifications to their jeep, they clash?
Straighter to the point, I recently installed both a cowl intake and hood spacers. Now, first off, I will admit to screwing up the cowl intake slightly. I drilled my hole to far towards the center and, after installing, the air filter would block the windshield wipers from working. Slightly smushed my filter too. So now my filter points to the left into the corner of the cowl.
I started having issues with acceleration, especially around 50mph. The xj would bog down until it downshifted. This would only happen though at cruising to acceleration. If gunning it to 65, full power. I figured it wasn't getting enough air, fab'ed up a half cowl cover and left the drivers side wide open. Fixed about 80% of my problem.
My thoughts, is the raised hood from my spacers I installed forcing too much air up and away from the cowl? Could it just be the filter stuck in the corner? (Nobody puts baby in the corner syndrome?)

 

Why do hood spacers if you already have vents? Spacing hood is way of doing it for people that don't want to cut their hood.

 

Take the hood spacers off and see if its any better,All i can think of is the hood is pushing the low pressure spot normally at the cowl up to center of the windshield.What brand cowl intake do you have ?

 

because I, personally, like the look the raised hood ::shrugs::

That's what I was thinking too, I'll have to find the bolts and give that a try. What brand? I just bought a filter, some flex hose, and a small section of 3" exhaust tubing. Made my own:

 

Ok, now I'm more confused.

Dropped the hood back down to its normal height, took the xj out on the highway and had very little improvement.

It's strange. If I cruise anywhere from 40mph and below and press the gas pedal a third of the way down the XJ will push ahead quite nicely. I just tested this on the back roads. Tested at 30. 35. 40. All the same. Great pick up power. Then came 45. Got it up to 45mph, let off the gas so it's start cruising and then, like all the other tests, pressed the gas pedal third of the way down and the rpms jump up 1 - 1.5k like its ready to go, then bogs back down and will slowly creep up to speed until I give it more has and it down shifts.
At 50 and 55mph it doesn't have the same oomph as below 45mph.

Could this be a TPS problem? Or maybe a fuel system? I haven't dealt with a problem like this before.

Ive tried that TPS trick where you push it in all the way then fully open the throttle to put it back into its correct position. This hasn't helped

Any ideas would be appreciated.

The evil 45mph mark.

 

Don't want to point out the obvious, but the torque converter locks at around 45mph. So when it locks up, the rpms won't raise the same as when it's unlocked.

At lower speeds, you'll notice the rpms raise without actually gaining speed due to the slip of the TC. Faster than 45 and at cruising speed, the TC is locked and won't unlock until the tranny shifts down for extra power.

Just making sure lol

 

When you installed your new intake did you hook all your vacuum lines up?

 

I will be the first to state that I'm still learning as I'm going along, so no worries on "pointing out obvious". It's all new to me at this point.

This does make a lot of sense. I just don't remember having such an issue back when I had the stock airbox hooked up nor do I remember seeing the rpms jump up then bog back down before it downshifted. Strange.

Tomorrow I'm going to check for vacuum leaks, check my fuel filter, replace my spark plug wires, and check my cat and O2 sensors. See if everything is in wording order.

Thanks!

 

All my vacuum lines? The only line I had to remove was the breather tube for the valve cover. Currently it's rocking it's own mini filter until I can hook it up straight to the intake pipe I'm running between the flex tube and TB

 

Sorry to dig up an old thread, but quick question with the last issue I was having.

Was driving to work two days ago and cruising at 40 the XJ turned off. The electric power was still there but no engine response. While coasting I threw it into Neutral and started it back up. It fired up fine and got me to work without issues but now my CEL was lit up.

I did some online searching and it sounded like my CPS was the issue. I was still having the downshifting issues after 45mph, so I assumed id have to replace both the CPS and TPS.

Went to Autozone this morning and had them use the code reader. I had 3 codes, each were my ignition coil pack. Wonderful. Bought a new one as well as a new TPS. Installed both and now no CEL and the XJ's running smoothly. I haven't been on a long drive yet to test my shifting, but with a little (uh oh) back road speeding, the downshifting problem has seemed to vacate my jeep.

Now, I don't own a voltmeter, can't afford one after the lovely purchases above. Should i still be concerned over my CPS? I've read everywhere that when a coil pack is shot, the jeep won't start. (Many I've read we're stranded, I got lucky)

 

You can get a cheapo meter for like $15 if I recall correctly.

If nothing is running badly then I don't see any reason to worry about it.

Regardless, there are a couple of ways a CPS can go bad... it can either be completely bad (and you won't be able to start) or it could be a heat related failure, that will happen when it gets hot (and then it'll stall out on you). However, I don't think you'd be able to start it right back up if that was the case. Somebody correct me if I'm wrong.

 

Well now my CEL is back on... Back to autozone

 

Just left autozone. Guess what! New CPS! FFFFK!

 

So it was the CPS? Good to know..

 

I guess so. I was just lucky and my ignition coil and (assumed) TPS went out at the same time.

I'm on the verge of a man temper tantrum though. Damn CPS is not fun to change whatsoever. I'm lucky I have ramps to elevate.

Spent the rest of the night figuring out how to get it out. Got the new one installed...works worse than my last one!! So now I have to pull out this sensor, go exchange for another hoping that one will work, and install. Grrrr!! Anger.