Smokinquack

I'm a new member, been lurking and have found a ton of good info on here since I took on my jeep project. Just did the ubiquitous oil adapter leak. Anyway mine did the same thing, first sputtered at 3000rpm, then 2000rpm, then just above idle. Thought it was fuel pressure but it turned out to be the catalytic converter. It melted and clogged up the whole exhaust. Just another thought for ya

cruiser54

Easy enough to check.

And OP, ever gandered at a spark plug?

Cruiser’s Vacuum Test for Exhaust Restriction

Your vacuum gauge should come with an instruction booklet outlining this procedure. Hook the vacuum gauge up to a source on the intake manifold.
Start the engine and note the vacuum reading. It’s usually 17 to 21 inches of vacuum. Throttle the engine up to 2,000 to 2,500 RPM for 20 seconds or so and the vacuum reading should stabilize to the same reading you got at idle.
Let the throttle snap shut. The vacuum reading should shoot up about 5 inches of vacuum higher for a second and then come quickly down to the original reading.
If the vacuum reading stays high and comes down slowly with jerky needle movements, you have an exhaust restriction.

stoneysxj89

Id say check filter. Then replace pump? Anyone else have input? I finally figured my issue out but it was due to cracked head

CherokeeCam

Just an update, tried to see if it was an injector issue by removing the connector and seeing if it ran better or worse then to the next cylinder. Each time it seemed that it was running worse. Couldn't rule out to one cylinder.

I then replaced the spark plugs and ignition coil. Plugs were 10 months old, not in terrible condition. I did notice in plug 3 & 6 that some smoke came out when I removed the old plug. Not sure what that could be?

Ran longer before having idle issues, but had issues. I then figured that maybe the injectors were the problem. I pulled them, put a bottle on each one and went to see if they all sprayed but #3 came off the rail. Looks like some of my injectors need the pintle cap replaced. I know all the fuel injector holes looked wet as if fuel was coming out and looking down the throttle body there was fuel so I can assume that fuel isn't the issue.

ehall

If you have a long metal rod of some kind (screwdriver, prybar, whatever), put one end on your ear and then touch it to each injector body. You will hear clack sound when injectors are firing.

I had a contact break on one of my connectors, ran like a turd whenever the injector wire shifted around

CherokeeCam

Turns out was intermittent failure of the new CPS. Mechanic swapped the new one in and everything worked good.

Thanks everyone for the help. I wouldn't have thought that would have been what was wrong with it.

stoneysxj89

I would take the filter out, then put a scrap fuel line on it with hose clamps then try to prime it. Thatll rule oit the filter, although you should be able to tell if your filters bunk when you take it off