After SeaFoam = Random Hard Starting

Started a new thread b/c it's a new issue now - instead of just a CEL, now sometimes it won't start...

I SF'ed my brother's '00 XJ w/ 185k on it 3 days ago. The next day he said that it was hard to start once and that the CEL was on. We took it to AutoZone to pull the codes and he had two. One we had seen before - PO456 and the other was misfire in cylinder 4. I pulled 4's plug and it was gapped .067 or something - way off. I replaced plug and disconnected battery to clear the codes. It started right up.

He said that yesterday it would hardly start all day. He said it was very slow to turn over and he'd have to try 5-6 times to get it to finally fire. He decided not to drive it b/c he was afraid of getting stranded. This morning though he said it started right up.

I had him buy 5 more plugs today so that we can finish the job in case the others are off too. Any ideas on this hard/slow start? I haven't been around to hear it yet and it seems to be intermittent. My first thought is battery, but I've usually only seen good or bad - not tempormental. I have all day tomorrow to mess with it, but obviously I'd rather just know what to narrow it down to in advance. I've SeaFoamed 4 vehicles so far and never had an issue. What are my chances that it could mess something up? Is there really anything that can go wrong? Oh, it's not throwing a code either - well, at least the CEL isn't on, but I'm assuming that means no code.

Sounds like corroded, dirty battery connections/clamps and or the battery is about to die. They usually act that way for a short while before they die in my experience.

Seafoam job would not cause it to crank slowly.

should change plugs either way-- crap will get on 'em and begin to foul them after cleaning. I would have a local parts store check battery and go from there-- my guess is that battery was going bad before you started the Seafoam cleansing.

--Shorty

Well, we changed the plugs today. Every plug was overgapped - probably just old. Ranged anywhere from .051 to .079, but most were in the .065 range. Kinda hard to believe that all wore out that bad, but the job is done. The Jeep has started fine for the last two days and I looked at the battery and all connections are solid, water is fine and it looks relatively new - w/in last 2-3yrs maybe. Dunno - hopefully just an isolated incident...

remember that the two toughest things for a battery to handle are heat and vibration (both are worse in an XJ that many other vehicles). I would still try to load test the battery and make sure it's up to snuff. I remember that when I lived in Clearwater, I would only get about three years to a battery (they were cheapos cuz I was a cheapo, but three years was all they'd give me)

--Shorty

I have to say, I tried seafoam today in the intake and was a little dissapointed. Not nearly enough smoke. I was expecting more but it did work really good. I know this has nothing to do with your problem so I'll say good luck with that and bump

gone postal said:

Well, we changed the plugs today. Every plug was overgapped - probably just old. Ranged anywhere from .051 to .079, but most were in the .065 range. Kinda hard to believe that all wore out that bad, but the job is done. The Jeep has started fine for the last two days and I looked at the battery and all connections are solid, water is fine and it looks relatively new - w/in last 2-3yrs maybe. Dunno - hopefully just an isolated incident...

Click to expand...

Jeeps are just amasing aren't they? Still running with plugs worn out at a gap 200% of spec!:shocked:

Come to think of it, the Seafoam probably removed carbon build up on the spark plug electrodes that had closed the gap to spec! So there you have it, Seafoam CAN be bad for your Jeep!, LOL.

what does seafoam do and can you use it on a camaro motor (3800 v6...that's what I put in my comanche cause it beats a 4.0...well, usually...but it IS better than the 2.8 v6 hands down. yay 215 horse!)