Topic: Idling very rough and has no power

[cmb516]

Hey guys so I just drove my 1997 Wrangler back to school (600 miles) and it ran good until it started to over heat, checked the antifreeze and it was low filled her back up and was on the road running good again. Last night I drove to dinner and it ran fine on the way there, but when we left it was very hard to start, idling very rough like it was going to stall at any moment, and it had no power what so ever when I would try and accelerate. I had to stay on the clutch just tog et it to rev up to be able to accelerate. I was looking around today and no lines seemed to be loose or anything like that, but I did notice what looked like a 2-3 inch long crack in my exhaust manifold. I was wondering if that would be causing it to run like crap or would it be something else. Any help would be appreciated

[sharpxmen]

the crack won't cause anything of what you describe.

all i'm saying below is based on the fact that you said your coolant was low - i'm not saying is the only thing causing that behavior
1. Check the oil to see if you have water in it (will be white and foamy).
2. Remove the spark plugs and inspect them visually, they should all look the same, if there are any wet and/or black focus on those cylinders
3. Check the compression on each cylinder

from what you describe it and the missing coolant would point to having the cyl head gasked blown between 2 cylinders. If your oil and compression checks out then you'll need to investigate further as it means that is not the case. Can be other reasons but i would start with that first. If you feel that there is no way it's compression related then you can check your fuel and spark which can also cause your loss of power.

[Dylan]

Couldn't hurt to see if you have any codes thrown.

From what you describe it sounds like you have a dead cylinder.

[cmb516]

Thanks for the ideas, how do I go about checking compression I am at school and very limited with tools?

[Jeffy]

I agree that it sounds like a dead cylinder.  It could be something as simple as a bad spark plug or injector and not a compression issue.  There will probably be no codes unless it's a fuel injector.  I'd run the engine and then start pulling spark plug cables (carefully) and see if there is any change.  The 2.5L can run on 3 cylinders and it will sound almost normal until you try to move, then it's really underpowered.

[sharpxmen]

Thanks for the ideas, how do I go about checking compression I am at school and very limited with tools?

you can pull the spark plug wires one at a time (like Jeffy said) and see if you have a cyl or 2 that don't contribute. I would check the oil too just in case (not sure how much coolant you were missing but just in case) - if it's white-ish then you def have a cyl head gasket issue.

to check compression you need a compression tester, you can find them at about $15 or so on sale (harbor freight has them i think), or you can rent one but will take you probably $7 if not more so your choice.

like i said, i am leaning towards the cyl head since you mentioned the coolant, if that was just a coincidence then it could be something else - btw, have you checked the level since you added antifreeze? has it gone down at all, if it didn't then probably it's unrelated.

[cmb516]

There was a code thrown and it was 43 which is a misfire in one of the cylinders, I will get in there and check the plugs and I'm going to change the oil since it is in need anyways and see if there is any coolant in the oil, thanks for the responses. 

[cmb516]

So i changed the oil and pulled the plugs. There was no coolant in the oil but the two plug tips closest to the firewall were white.  I changed the plugs and the distributor cap and it is still running terrible but the check engine light did go off once I changed the plugs.  I am starting to lean towards a blown head gasket as my culprit behind this. 

[sharpxmen]

So i changed the oil and pulled the plugs. There was no coolant in the oil but the two plug tips closest to the firewall were white.  I changed the plugs and the distributor cap and it is still running terrible but the check engine light did go off once I changed the plugs.  I am starting to lean towards a blown head gasket as my culprit behind this. 

what colors were the other 2 plugs. Also, did you pull the plug wires out one at a time to see which cyl in not contributing? White plugs can mean too little fuel, if the other 2 were black you could have an issue with the injectors on those 2 cylinders. If you didn't have any coolant in the oil then it's not that likely to have the gasket blown, i've seen it happen but like i said, it's not that likely. do the spark plug wire test first and post back the results (you can also pull the injector connectors one at the time instead if you are afraid to get shocked by the spark which you prolly will).

[cmb516]

The plug closest to the firewall was white the next one forward was about half white they other two were brown in color.

[sharpxmen]

The plug closest to the firewall was white the next one forward was about half white they other two were brown in color.

sounds like you're not getting enough fuel on those cylinders (the ones that are white in color). I would start by measuring the fuel pressure. If that turns out good then you'll have to look at the injectors (maybe the filters on those 2 are clogged).

[97 TJ - I dont wave]

Sure sounds like the throttle positioning sensor.?.?.?

[Dylan]

I'm definately leaning toward the lack of fuel theory...

If you run too lean, it'll run hot (overheating mentioned); running too lean will also lead to higher exhaust temps (cracked manifold); too lean tends to leave light-coloured deposits on the plugs; and last off a too lean condition has pretty much the same effect as no fuel, the cylinder will be dead.

I'd echo checking your fuel pressure and the injectors on the two rearmost cylinders.

[cmb516]

Thanks for the replies guys how would i go about checking the fuel pressure at those two cylinders?

[sharpxmen]

Thanks for the replies guys how would i go about checking the fuel pressure at those two cylinders?

you check the pressure at the fuel rail (would be for all injectors in that case). once you got that out of the way (you should have 49psi pressure at the rail) take the fuel rail out and remove the injectors, look at the inlet of each of them (specifically the 2 with the issue) and see if the filters inside the inlet are clogged.