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3vze compression test

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Old 10-04-2006, 10:00 AM
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Red face 3vze compression test

My used 3vze which I just installed is smoking like crazy, like a super rich mixture half burnt. It didn't start out like that though. It took a couple of days after getting the timing and tps adjusted and the motor idling and reving. I did a comp test with the motor slightly warmed up.
1-80
2-90
3-85
4-75
5-80
6-90
Could these be low because I am not warmed up or am I screwed? The plugs had a black film on them but it did not seem like oil, or maybe I am just optimistic. I am hoping it is just running really rich. I have spark to each plug and plenty of fuel. Thanks for your time and ideas.
Old 10-04-2006, 12:05 PM
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That is really low compression, should be 165ish.

They are very consistant though, I'm wondering if your test is faulty. Normally when these engines die it's one or two holes, not all and all consistant.

How are you testing compression?
Old 10-04-2006, 12:21 PM
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I have a good compression tester, two actually and I used them both to be sure. Please see my smoke ring post to see where I am going with this. Thanks.
Old 10-04-2006, 12:37 PM
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But how did you test?

All plugs out?
Fully charged battery?
5 beats on the gauge?, then maximum it'll get?
Did you then add a little oil to the cylinder to determin if it's rings?
Old 10-04-2006, 12:46 PM
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I got a question for you guys...

How in the sam hell do you get the compression checker IN the damn sparkplug hole and seated like a sparkplug?? On my compression tester (that ive never been able to use for this reason) there is a big arse 3/8" hose that is in the way!

Is there some kinda special socket one needs?
Old 10-04-2006, 01:08 PM
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i thought there was a fitting you screwed in then "QA" the hose to the fitting... to avoid said problem... (or something to that effect)

like this



i thought the rings took longer to seat than "a few days"

ive heard a little oil usage for the first 500-2000 miles is normal (till the rings fully seat)

Last edited by snap-on; 10-04-2006 at 01:10 PM.
Old 10-04-2006, 01:37 PM
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I use the snap-on one. Two piece unit with an airchuck connector between them.

Screw the hose piece in, connect the gauge part.
Old 10-04-2006, 02:02 PM
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spark plugs out, battery charged (may be a little low but crankin pretty good), 3 to 5 hits to max, I did put oil in and it jumped 30 psi. Wouldn't this help compression if the rings were marginal? I have since pulled the cover plate on the timing belt and when the crank pulley is on 0 the cams are not on there mark. The crank pulley has moved away from the front of the motor about a 1/4". Could I have sheared the woodruff key and spun the lower timing gear enough to mess me up? I am disassembling at the moment to find out. Please check out my smoke ring thread, I hope I am on to something. My compression could read poorly if the valves were open a little during the compression test, but it doesn't seem like the improvement with oil would have been that dramatic.
It is not impossible to get a compression testerwith hose in the hole but you do need some experience with the feel for the thread, I tighten it by turning the hose, it is tight and awkward.
Old 10-04-2006, 03:14 PM
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Originally Posted by snap-on
i thought there was a fitting you screwed in then "QA" the hose to the fitting... to avoid said problem... (or something to that effect)

like this



i thought the rings took longer to seat than "a few days"

ive heard a little oil usage for the first 500-2000 miles is normal (till the rings fully seat)
Mine doesnt have that air chuck it just has a hose affixed to the end thats going to screw into the sparkplug hole. I suppose ill pick one of those up soon since they arent that pricey...
Old 10-04-2006, 04:53 PM
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I retested 2-6 with the throttle open
2-115
4-124
6-116
It's better, and I expect similar results on 1,3,5 but it's dark and cold now. Thanks for any advice, I am still smokin', the timing is on, I even rechecked the timing belt install. I am not sure what to do next.
Old 10-04-2006, 08:08 PM
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kinda a long shot but is your oil level correct in the crank case? The only other thing I can think of is excessive blow by building up pressure in the crankcanse and blowing oil out the PCV into the intake...

what color is the smoke and what does the smoke smell like?

Also were any of your spark plugs unusually clean or wet?
Old 10-05-2006, 07:12 AM
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I did check the throttle body and it was not oily at the intake. The plugs were wet but not clean, dirty from getting it going. The smoke is dark grey, like unburnt fuel. There is one last possibility which is bad gas, my last hope for now. I didn't think there was any air/fuel mixture to adjust on this system so I will try some new gas as the truck has been sitting and I am getting to the bottom of the tank.
Old 10-05-2006, 07:36 AM
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Without good compression you are not going to get good combustion, so there will be a lot of unburnt fuel. IMHO you need to chase this compression issue down. Changing your gasoline isn't going to do a thing for you.

With my piston hole on the left bank (valve cover vent goes right in front of the throttle body) the entire upper plenum was soaked in oil - pooled and dripping. The fact that yours is dry would indicate that you don't have a similar issue. Good news.

You still need to determine why the compression is so low. However, a strong indicator of rings is that compression when up 30psi when you put a little oil in there.

Do you have any idea how many miles are on this engine? Could it just be worn out?

Last edited by MonsterMaxx; 10-05-2006 at 07:37 AM.
Old 10-05-2006, 09:13 AM
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well from your symptoms it sounds like your getting way too much fuel than what you actually need. You could have a cold start injector that is pissing fuel into your intake, which washes down your cylinder walls and can give you low compression readings.
Old 10-05-2006, 11:57 AM
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umm, assuming he's pulling the efi fuse when he does compression check this shouldn't happen, though it's certinly a possibility while running.

You are pulling the efi fuse right?
Old 10-05-2006, 12:17 PM
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Originally Posted by yota_krazy
well from your symptoms it sounds like your getting way too much fuel than what you actually need. You could have a cold start injector that is pissing fuel into your intake, which washes down your cylinder walls and can give you low compression readings.
I know this was recently the problem with a friends honda when the fuel presssure regulator shot craps and it was dumping about 3 times as much fuel in as it was suppsed to.... compleatly washed down the cylinders and he had 30psi across all cylinders...
Old 10-05-2006, 09:35 PM
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Thanks, there still may be hope. I have no idea how many miles this engine has. It was sold to me with under 50,000 but I don't think so. The jumper wire makes no difference in idle but the check engine does flash when I turn it on with the jumper. It makes sense that I may be getting too much fuel because something seemed to change suddenly. I wasn't getting all the smoke at first. I will check out the too much fuel theory in the morning.
Old 10-06-2006, 04:49 AM
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When jumpered, if it's got no codes it'll just blink steady. If it's got a code, a pattern will emerge.
Old 10-06-2006, 02:34 PM
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Well if you read his 3rd post. To me it sounds like a timing issue.
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