arp09a

Before work done, engine was missing a little at idle. Just replaced freeze plugs. RR intake/exhaust manifold to get to them. Also replaced plugs and boots. Ran just as before work with a little missing at idle then after a week, missing more and at about 2750 RMP the engine surges or runs then stops then runs then stops. It is like it is pulsing. Not sure if it is a plug issue or an injector issue. Since I can not pull plug wires one at at time to see if I get no change I tried the injector wires. Could not tell anything from that. Nothing indicating engine codes present, no lights on dash. Any ideas what it might be before I take it to the shop?

cruiser54

Probably a good idea to include year, engine etc in your post and/or your profile.

arp09a

Oops that would help, this is a 2001 Cherokee Sport 4.0L automatic

Coastal

try getting them to put pictures of it on milk cartons


in all seriousness, did you make sure you had the right spark plugs and properly gap them?

are all plugs wires firmly connected at both ends?

arp09a

Assumed correct ones since gave info to parts house and it was a NAPA store but ...I will check that out. There are no plug wires, it has the bar with caps for each plug and I replaced those as well. Does that bar that serve as the plug wires perhaps have components that would cause the missing thus I might need to replace that as well?

Just did some more research and will try replacing the coil pack. I noticed that two of the sleeves that the bolts go thru are cracked so there may be other damage to the unit causing the problem.