mikey98zj

Hey guys, been having some serious misfiring on my 98 ZJ. I've searched and read a lot of the posts on here and other forums but I was going to ask you guys about drygas. Anyone ever use it? Has it worked for you? I checked the plugs on my truck and they're clean, throttle body is clean, and oil/filter were just done yesterday and the misfiring started before then. I'm thinking it's fuel because the truck started acting up after I put some fuel in it, so I think I may have a bad batch with possible water in it and I wanna see if that's the problem. The truck is going to my mechanic on Monday but I want to see if I can fix it on my own before then. I've read about the IAC valve being cleaned and also checking the crank and cam position sensors, but I havent checked those things yet. I feel like the truck is just starving for fuel. It has a rough idle/misfire, and it slightly goes away while driving. If your on the highway and give it gas without downshifting, the thing misfires so bad it shakes the entire truck and then clears up. I was also in traffic the other day and I switched lanes to speed up and the truck misfired so bad that I literally felt like i was on a chatter strip, no exaggeration. Someone help?

KF2M

What brand of plugs are you using, and how old/miles are they? Are they gapped to .35? The reason I ask is that most Chrysler products like Champion plugs (sometimes NGK). With Champions I usually get about 20-25k miles on them before they start to act up much like you're describing.

99FreshenedCherokee

everything you described happened to me. Its your upstream oxygen sensor. Before you got out and spend like 200$ on a mechanic go buy an o2 sensor, just make sure to buy the right brand. I had to buy two.the first one i bought was messed up; I lost my reciept and had to buy another one. If you can, get one from NTK.

FAlfani81

Could be a bad injector

purplegrocerygogetter

What is dry gas? Is that like that seafoam stuff?

MilanJeep

I'd seafoam it then replace your O2 sensor and you should also consider neon injectors.

mikey98zj

Thanks for the all the input! I've heard about the seafoam idea but not entirely sure on what it is exactly, so I'll do some research. As far as plugs go, I probably replaced them about 6 to 10,000 miles ago and after checking them they seemed totally fine. No gunk or buildup, but a somewhat greyish color to the tip which makes me think towards a lean misfire. No CEL has come up , wouldn't it if it were an o2 sensor? And as far as i know the plugs were champion plugs. My mechanic is fortunately a family friend who will usually take a look at my truck for free, tell me what's wrong, and then ask me if I want to fix it or if i want him to fix it. Most of the time he charges VERY little for labor and hands me the receipts for the parts. He's a good dude.

mikey98zj

My father told me about it. Its an additive that's supposed to dry water out of fuel and it's also supposed to be like an antifreeze for fuel lines.

99FreshenedCherokee

when my o2 sensor went out i never got a cel, just a light hesitation, once i replaced it with the o2 that DIDNT work it started shooting out cadoes. It doesnt always throw out a code, especially if you have had it for a long while now

mikey98zj

Really? Well that's good to know thanks. Trucks going in tomorrow though so I'll find out what the hell is wrong with it. Thanks for everyones responses.

Rjmils

Sounds like the crank position sensor to me

mikey98zj

It was a bad distributor. thanks for everyones input though.

Rjmils

Cool glad u fixed ur problem