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Discussion Starter · #1 · (Edited)
my jeep is a 1995 and i have two of these wonderful jeeps but for some reason this one in cylinder 2 has really bad compression and it also does not stay when being tested it quickly decreases in compression. but only one cylinder, please help. i replaced all ignition coil and all sensors. also there is a new head gasket and valve stems and seals. and another things it does not want to stay running. it runs really rough and won't accelerate anymore. when i press the gas it shakes the jeep.
 

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Ok, first why did you change the head gasket and etc?

Could you have missed something when doing that?

Did you do a leak down test to determine if it is an upper or lower motor problem?

Obviously your compression issue is probably why its running bad; but figure out if it is an upper or lower issuse and that can help determine what your next step will be. Im thinking at a minimum you will need to pull the head and verify what failed, or went wrong.
 

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Discussion Starter · #3 ·
I changed the head gasket because there was a slight leak of anti freeze into to engine. when i took everything off i had it taken in to be checked for warps and cracks and nothing came up. so we put it back together with all the new parts and everything and that's when i tested the compression because it still did not run right. and it came up to 90 psi and fell fast. when all the others were at 120psi and stayed.
 

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Discussion Starter · #4 ·
we just tested it in out shop and it has a 70-89% of leaking. its hissing in the engine but we cant really tell where... no bubble in the coolant. also if i take the head off again do i really need to drain the oil if the engine in still in the jeep?
 

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1. When doing a leakdown make sure the cylinder is on compression stroke and both vavles are closed.
2. Is air coming out of the dipstick tube (lower end leak on pistion rings)
3. is air coming out the throttle body ( intake valve leak)
4. is air coming out the exhaust (exhaust valve leak)
5. also check to make sure the block is not cracked or corroded around the cylinder in question

You can leave in the oil
 

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Next check I would do is pour a little oil down the cylinder and do another compression test. If the compression comes up, then you have a problem in the cylinder; probably rings, but could be something else as well.

Antifreeze is horribly hard on an engine and its possible (assuming it was that cylinder it was leaking into) that you just damaged the rings/cylinder.

Could you have overheated the engine? Could be cracked like mentioned in the last post.
 

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Discussion Starter · #7 ·
never ever overheated in my life time with the jeep. it is tuned and cleaned every 5,000 miles. for the oil test it stays the same.

i noticed if i unplug the iac valve nothing changes. it still runs bad and had a rough idel.

i put a hose to my ear and rockers and none are ticking and also i did a smoke test with a smoke machine looking for leaks. and there is none. i have every tool in the world but can not seem to fix it.

if you need pictures or videos. i can post some.
 

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Do the oil test, verify if its low end or head and go from there.
 

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oh, here's a thought, could you have over tightened a rocker after replacing the head?
 

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never ever overheated in my life time with the jeep. it is tuned and cleaned every 5,000 miles. for the oil test it stays the same.

i noticed if i unplug the iac valve nothing changes. it still runs bad and had a rough idel.

i put a hose to my ear and rockers and none are ticking and also i did a smoke test with a smoke machine looking for leaks. and there is none. i have every tool in the world but can not seem to fix it.

if you need pictures or videos. i can post some.
do the leak down test and or compression test with oil, check the rockers for proper gap or torque to the pushrods. Your problem is with the compression on number 2 cylinder. If these don't pan out remove the head and redo it. If it ran decent before you changed the head gasket it should run decent after the new part(assuming it ran and you only had a slight leak into the cooling jackets)
 

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Discussion Starter · #13 ·
i watched and read the entire book on how to but the head back on and to torque it. i have a very very nice torque wrench to do the job.

who ever said that you can over tighten a rocker.. i did not know you could do that. im really stupid there. but i ran the engine with the valve cover off and the rockers were all running fine. if that even matters?

the past hour i took the head off put a new gasket on and put it all back together... and found nothing. all the compression is back to normal tho. # 2 is the same as the rest and perfect. but the problem still occurs. i accelerate and it shakes the jeep and runs really rough. ( wont let me go over 3mph)

im replacing the idle air control valve because that tested to be broken. but that also has nothing to do with the shaking.. or does it??

thanks guys so much for helping :)
 

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Ok, now that the compression is normal you can check for other things.

Last IAC problem I had created a horrible idle and off idle take off problem. So its possible.

Have you verified your firing order?
Have you verified all your wires are good and attached properly?
Loose spark plug?
Loose cap?
Vacuum line issue?

oh, and yes you can over tighten the rocker. It will still work but if its over tight it will keep the valve open slightly when its supposed to be closed. Basically it would be bottoming out the lifter.
 

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Discussion Starter · #15 · (Edited)
just replaced the cap and router. new wired were put in last year

and all were checked for cracks.

for the vaccume leak there is none i did the smoke test.

the order is not hard to mess up its only a 4 cly.

im waiting on auto zone to pick up there phone so i can see if the vavle came in. they tend to be really stupid in my town. they all drive Honda civics and don't know what there talking about.

i will be posting link to a video of my jeep and how it runs later today.
 

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Honestly, I think all those super chains hire wanna be's that do not know anything.

Went to the new AZ to give them a chance, and asked for a spark plug... he couldn't look it up because the system required a make and model. So I gave it to him, and surprise the 1984 Kawasaki was there, but the spark plug listed was a XXX7 and I wanted an XXX8. He couldnt go get it because he wouldnt know where to start looking. :wall:

Pretty sure they are right next to each other there captain!

I know the order shouldnt be hard to mess up, but only firing good on two cylinders can cause what you describe; it could run and only go 3mph if youre lucky. But just tossing out ideas just in case. Im no expert on IAC valves; but if I understand them correctly it should mostly affect idle and off idle drivability. Once you get past a certain rpm the thing should run near normal.
 

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Discussion Starter · #17 ·
so i got the new iac after waiting a hour in line... and put it on. when i put it in drive or reverse the rpms drop. so i replcaed the starter iac tps wires cap routher coil plugs fule lines filter head gasket valve steam seals rockers rods and i think thats everything.... might as well buy a new car.

but anyways. the rps drop in drive and revers. why?

and it still runs really really rough and shakes. the video im going to shoot right now.
 

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Start the rig. forget the smoke test to look for leaks. Get a can of break clean, or starting fluid, Spray around the intake manifold, throttle body, vacuum lines to the break booster etc. Your engine should clear up for a second when you find a leak. Also are you sure the firing order is correct. Did the rig run Ok with the blown head gasket. It is very easy to get the intake manifold off set if the alignement dowls fall out.
 

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Discussion Starter · #20 ·
i ohm tested the fuel injectors and they all came up at 14.8 but the last one. it came up as 0 none not a beep. but there 70$ a piece. so i am totally screwed now.
 
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