drewfunk

I've had my 1990 cherokee for about 2 weeks now, and have put a good couple hundred miles on it. Its got the 2.5 and a 5 speed, 185k. When i got it, it seemed to run just fine. Now i'm noticing some power loss, especially when accelerating. Its most noticable when rowing through 1st-3rd gears you will feel the power lessen, then jump up, lessen again, etc. Almost feels as though its choked. The rpms arent dropping when this happens. Also seems to happen more after you've driven it a while. It starts up and idles just fine. Its also getting pretty lousy mileage, and i'm driving mostly highway and accelerating conservatively.

I ditched the airbox for a K&N cone filter. Just bought plugs and wires that i will instal tonight. Any reasons my cherokee would be acting up? I'm new to them. I love the thing, and it has pretty decent power for a 4 banger when it behaves. But the power loss and mileage are frustrating me.

chill

tune up is a good start. check fuel rail presure. then something that old I'd start replacing sensors. 02 first. could also check compresion. pluged cat can also cause those problem.

mudfrog

Those are the typical symptoms of a plugged converter.

drewfunk

Thanks for the prompt replies! How would i go about checking the converter?
I'm rather scared of checking compression on a rig with 185k, might not like what i see

Also a random question: What is the wrench size needed for the oil sender? I'm picking the wrench up after work and dont know what size i need....

DFlintstone

Can't help you on the wrench, except that you should start gathering lots of them! I've been getting tools from Napa, since they are guaranteed and just as important as anything, everywhere. (S-K, Proto, Snap-On, even Craftsman, fine, but good luck getting a replacement when you need it)

I guess you can google "vacuum test for restricted exhaust". I haven't tried it...yet. One of these days, gonna go out and plug my exhaust and try it.

I had one doggen once. I loosened the header pipe flange enough to allow a good leak. BINGO, that was it, had power. Good luck!

drewfunk

Alright, havent had much of a chance to look at the engine lately. Did replace the plugs and wires.

But its still running bad, and getting worse it seems. Its also overheating. I bought it with the temp gauge not functioning so i dont know the overheating details without the gauge, but yesterday after driving in town for a long time and sitting in a drive through, i could hear the water boiling so i parked her for a while.

Any other ideas on whats causing this? The previous owner claimed to of replaced the head gasket.

It just seems gutless, but when i had bought it a couple weeks ago it ran great.

Morrid13

Check your vacuum lines on my jeep i had aline split it was doing the same thing as yours

DFlintstone

I cracked my 2.5 head overheating it with a bad head gasket...long ago. One quick test is to fill it to the brim then power-brake it with the cap off. If when you put the engine under load you see "action", (or a geyser) at the cap you know right there the head is coming off. It might surge some but if it keeps up that's defiantly not good. Also of course milky oil or oily water are not good.

drewfunk

I will try the power-break troubleshooting. I checked the radiator level a couple times and it seemed to maintain a consistent level so i didnt think it was losing coolant.

Also, when i changed the plugs a week ago, all were consistently dry and a light tan color, so i assume it has a healthy fuel mixture. If the rings were bad wouldnt the plugs be oily?

I also noticed moisture in the vent hose from the valve cover. Abnormal?
I'm starting to think this may be a head gasket issue, which is a huge bummer on a daily driver.

mudfrog

My money is still on the cat. Clogged cats will also cause over heating due to the exhaust not being able to escape.

xj_maniac_newb

Disconnect the cat to check, if it helps then that's your problem.

DFlintstone

XXXXX on the cat/exhaust. I just mentioned the power brake test cause it's pretty darn easy and you mentioned overheating. (2,500* combustion gas warms the coolant a tad). Not sure I'd worry allot about just a little sign of moisture. Idk. When a hot engine sits and cools "an amount" of air is drawn in each time. I saw one (Volvo) with a hardened O ring on the dipstick tube. Car was fine but there was a little milky goopis around that. She didn't drive it far, or often.

drewfunk

Alright guys, i'll be taking her out for a noisy cat-less drive in a bit. (Just dont tell any of the moderators...)

xj_maniac_newb

The only legal reasons to for the cat to be removed are

1. If it falls off on its own

2. To remove and replace a damaged/nonfunctioning cat

Your cat is nonfunctioning, nothing wrong with removing it as long as you have plans to put another on.

DFlintstone

I loosened the header pipe flange enough to allow a good leak. BINGO, that was it, had power. Good luck!