the plugs i have been using in my 1994 are the stock champion rc12lyc. with 8000 miles on the plugs they are starting to turn white and pit a little(too hot i believe). Would using the champion rc9yc from the older 4.0s be a good alternative or is that too cold? Jeep does have a bunch of air, exhaust, and fuel mods but it's still naturally aspirated.

 

When was the upstream O2 last replaced? Have you checked for vacuum leaks? If you're having trouble with the spark plugs called out for on the emissions sticker on the firewall something ain't right (no idea when the 4.0 moved from RC9LYC to RC12LYC, later models use RC12ECC)

 

no leaks. that i know of. Good point on the o2 sensor i never changed it maybe i'll try that. weird mpg is still about 18-19. I think 1991 was when they changed from the rc9yc to the rc12lyc plug assuming it's because of the high output thing. Thanks!

 

Anyone know how the infinity sound package tweeters are wired up? Like a diagram ?

 

OK. So I've found out that the tweeters are wired inline with the door speakers. So, in theory, if my door speaker works and the tweeter doesn't, than the problem has to be in the wiring to the tweeter right?

 

I have a "grinding" noise coming from beneath my jeep.

It only makes the sound after driving for at least 30-45 minutes straight and a speed of at least 40mph. I hear it a tiny little bit driving straight but majorly when turning. After i park and let it sit for a bit it goes away.

Can anyone help me with this?

Zach

 

What's the best muffler and cat that will give me a deep tone that's not ricey? I only want it to be loud when I floor it. I mainly want it to be free flowing to give me better mpg.

 

!

 

Can anyone guide me to a good link on converting my rear drums to Grand Cherokee discs?


Thanks.

 

Clicky: https://www.cherokeeforum.com/f67/al...o-here-103854/

 

Yes, or within the wiring itself (bad splice to the door speakers). If you really wanted to you should be able to hook them up to any stereo system with speaker outputs and run them at a very low volume for testing. From the info in the FSM I'm guessing they just have high-pass filters, probably a simple capacitor, on the back.

You can also test the wires going to the tweeter with a multimeter in AC volts mode. Play something at a low volume and you'll be able to see the needle move if everything is okay.

I'm not sure if the tweeter has any metal mounting on that little bracket, but if it's somehow grounded to the body there could be issues.

 

I'd start by taking it for a drive and getting it up on jack stands as soon as possible. Turn all the components by hand and see where the grinding noise is coming from. Going to guess you have some lubricant that's past due for a change and stops lubricating once warmed up. When were the fluids last changed?

 

Which direction should the electric fan be moving air? I just bought my 95 Cherokee Sport several months ago. Today while standing in front of the vehicle, I noticed that the electric fan is blowing air out of the engine compartment; not drawing in. Is this correct?

 

Nope. It sucks air IN through the radiator. Possible the wires are just crossed.

 

No grounding on the back. I looked for that. Lol.

There is indeed a high pass filter (well I wasn't sure that's what it was til you said it) but its there.

I'll give the wires a check with volt meter. See if they're getting anything. Then go from there.

Thanks.