Jeep went wacky.

SexJ1988 · Sep 20, 2016

Bought a 1988 Cherokee 4.0L 4wd Sunday. Drove great when I test drove it.

Drove about an hour home started misfiring, then died. Restarted it and now it runs super rough, also started making noise kinda like piston slap or lifter tick.

I've replaced plugs, wires, cap, rotor, CAS, oil, thermostat.

Still nothing.

It literally was like a sewing machine when I test drove it.

I was tinkering and noticed that I can unplug cyl 1&2 injectors at the same time and nothing changes, but if I unplug any of the others it stalls.

Help.

RCP Phx · Sep 20, 2016

SexJ1988 said:
I was tinkering and noticed that I can unplug cyl 1&2 injectors at the same time and nothing changes, but if I unplug any of the others it stalls.Help.

That should be your first clue as to what's going on. If you have confirmed "spark" then that would lead to a injector problem! Have you done a compression test?

SexJ1988 · Sep 20, 2016

Hoping to do compression test tonight, also may order injectors later this week.

I'm just confused as to why within 1 hour it went haywire.

Green Mesa XJ · Sep 20, 2016

If there was a bandaid fix it might have worn off.

Definitely start by checking compression

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SexJ1988 · Sep 20, 2016

I'm hoping to tonight, hoping it's all fine and everything will be fine if I replace the 2 injectors

scottmcneal · Sep 20, 2016

swap the injectors first before buying any. You could also try to clean them or have them cleaned by a shop.

90xj06 · Sep 20, 2016

welcome to the c101 connector! the injector circuit goes through it and you may have some corroded pins. i would start there. http://cruiser54.com/?p=24

SexJ1988 · Sep 20, 2016

Thanks! I'm going to try to clean that tonight as well as swapping the injectors around. I ordered a compression tester and it will be here Monday. Hopefully it's just the c101 or the injectors themselves.

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90xj06 · Sep 20, 2016

i also just bought an 88 2 weeks ago.

SexJ1988 · Sep 20, 2016

What thread do I post pictures in just to show it?

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90xj06 · Sep 20, 2016

i dont think there is a place to post them here.

Ecomike · Sep 20, 2016

I would check the sensor grounds, pull them, clean them and the engine block contact area were they terminate near the oil dipstick mount on the block, passenger side.

What did you do to the jeep before the problem started? Did you cris-cross the two spark plug wires on #1 and #2 cyls?

Possible cyl head gasket leak between #1 and #2, but do the asy stuff first. Also make sure the injector connections for #1 and # 2 are not switched.

SexJ1988 · Sep 20, 2016

Ecomike said:
I would check the sensor grounds, pull them, clean them and the engine block contact area were they terminate near the oil dipstick mount on the block, passenger side.

What did you do to the jeep before the problem started? Did you cris-cross the two spark plug wires on #1 and #2 cyls?

Possible cyl head gasket leak between #1 and #2, but do the asy stuff first. Also make sure the injector connections for #1 and # 2 are not switched.

I didn't do anything before it started that's the issue. I test drove it(ran great). Go about an hour towards home and it started acting up.

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SexJ1988 · Sep 21, 2016

https://vimeo.com/183578086

Here is a video for you guys to see what I'm talking about.

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Green Mesa XJ · Sep 21, 2016

90xj06 said:
i also just bought an 88 2 weeks ago.

Where are all these 88s coming up for sale?!
I might be too tempted to have another AMC Jeep this time with out the weak 2.8 gm motor .

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RCP Phx · Sep 21, 2016

I'd pull the valve cover and check to see if the rocker arms have backed off!

Green Mesa XJ · Sep 21, 2016

SexJ1988 said:
https://vimeo.com/183578086

Here is a video for you guys to see what I'm talking about.

Sent from my iPhone using Tapatalk

Wow, you've been busy!

Um, you've got very good oil pressure, someone may be able to identify that exact sound for you.

But I really think the compression test will help direct your next steps. If you've got no or very low pressure I'm afraid you'll need to pull the head and take a look, or maybe scope the cylinder instead.

BTW I use the tapatalk app to load video and pictures. Seems to be the easiest way

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SexJ1988 · Sep 21, 2016

RCP Phx said:
I'd pull the valve cover and check to see if the rocker arms have backed off!

Is that a simple fix if so?

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SexJ1988 · Sep 21, 2016

Green Mesa XJ said:
Wow, you've been busy!

Um, you've got very good oil pressure, someone may be able to identify that exact sound for you.

But I really think the compression test will help direct your next steps. If you've got no or very low pressure I'm afraid you'll need to pull the head and take a look, or maybe scope the cylinder instead.

BTW I use the tapatalk app to load video and pictures. Seems to be the easiest way

Sent from my iPhone using Tapatalk

I bought a tester it will be here Monday. No one local had one I could borrow or buy.

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Fred · Sep 21, 2016

It's easy to post photos from photobucket.

Jeep went wacky.

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