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General Forums => The Mess Hall => Topic started by: cmb516 on January 12, 2010, 03:42:49 PM
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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
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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.
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Couldn't hurt to see if you have any codes thrown.
From what you describe it sounds like you have a dead cylinder.
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Thanks for the ideas, how do I go about checking compression I am at school and very limited with tools?
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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.
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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.
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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.
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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.
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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).
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The plug closest to the firewall was white the next one forward was about half white they other two were brown in color.
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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).
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Sure sounds like the throttle positioning sensor.?.?.?
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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.
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Thanks for the replies guys how would i go about checking the fuel pressure at those two cylinders?
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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.
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I changed the injectors since I was going to switch to ford injectors anyway but it is still running the crappy. The injector that came out of the cylinder with the white plug did have crap on it so I thought that would be the problem but that is not it. Could you walk me through how to check the pressure at the rail? Thanks
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Also since my exhaust manifold is cracked could I have a bad O2 sensor causing this and would a code be thrown if I had a bad sensor because I have no codes after replacing plugs and injectors
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I changed the injectors since I was going to switch to ford injectors anyway but it is still running the crappy. The injector that came out of the cylinder with the white plug did have crap on it so I thought that would be the problem but that is not it. Could you walk me through how to check the pressure at the rail? Thanks
can't remember if you mention it or not - do you have a schraeder valve on the fuel rail? if you don't know what that is - it is a fitting that sticks upwards in the middle of your fuel rail between cyl 2 and 3, usually has a plastic cap screwed on it - to get an idea where it is look at my thread about installing an adjustable fuel pressure regulator in the Member's Projects section - i hooked up the adjustable FPR to the schraeder valve (but that was on a YJ, some TJs have that as well). Let me know if you have it and i'll tell you what you need to put together a fuel pressure check gauge.
Also since my exhaust manifold is cracked could I have a bad O2 sensor causing this and would a code be thrown if I had a bad sensor because I have no codes after replacing plugs and injectors
unless you have a big chunk missing i don't think the crack can cause such a problem especially that is isolated to 2 of the cylinders. I would still do a compression test if the fuel pressure checks out. Since you changed the injectors i assume that they were not the issue in this case (of course assuming that is not a case of a bad set that you put on or that 1 or 2 of the 4 you just installed are bad).What injectors did you use? that is also important (post a P/N).
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I do not have that valve on the fuel rail in the middle, the injectors I put in were ford 19 lb injectors design III that I bought off a guy on jeep forum.
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I do not have that valve on the fuel rail in the middle, the injectors I put in were ford 19 lb injectors design III that I bought off a guy on jeep forum.
those injectors will not work on your Jeep, replace them immediately with appropriate sized injectors - they are flowing roughly 17% less than what the stock ones are - this has been covered many times here, please read the FAQ about injectors on this site.
So that being said, changing the injectors with the 19# ones didn't provide any answers
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So i took the ford injectors out and put the oems back in. Anyway when I took the ford ones out the one that came out of the cylinder closest to the firewall had gunk all over it and it had only been run for about a min to see if it would run any better why would it fill up with crap that quickly? When I took the factory ones out the first time that one had crap on it too so I am wondering why that is happening to that one only?
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So i took the ford injectors out and put the oems back in. Anyway when I took the ford ones out the one that came out of the cylinder closest to the firewall had gunk all over it and it had only been run for about a min to see if it would run any better why would it fill up with crap that quickly? When I took the factory ones out the first time that one had crap on it too so I am wondering why that is happening to that one only?
can be a bad intake valve. Take the compression, it's fairly easy - buy a compression tester or rent one (they are about $15 for a cheapo, you don't need a brand name). you need to take out all your spark plugs and screw in the comp tester in the cyl one at a time. crank the motor about 7 times on each cyl and write down the results. do it cold and then warm up the engine and do it again. If one of the cyl is low compared to the others squirt some oil in it (couple of oz is enough) and take the comp again - if it gets to the same level as the other ones then the rings are the problem, if it's the same then there's a valve or valves that don't seal.