#84372, "Lost compression in EVERY cylinder, please help!"
OK, I will try to explain this in as much detail as to get you all the information you will need. To begin, I was adjusting my AEM adjustable cam gears to zero them out after rebuilding the engine. The engine has about 2k miles on it at this point, but it idles rough and I decided the old cam degrees were not going to work now, so I zeroed them out. I do this, start the car it idles great. I yank the throttle from under the hood to give it a rev, it does great, then comes down, through idle and just dies. And now it won't crank back up. I have tested fuel pressure, it is 50lbs. I checked for spark, all are GREAT. I checked compression, and in EVERY SINGLE CYLINDER no compression what so ever. Is it possible the the cam somehow turned more than the 10 degrees allowed by the adjustable cams and through the cam timing off??? I know that is a crazy idea, but the only conclusion I can come up with for losing compression in all the damn cylinders is an out of time camshaft. The timing marks all line up fine. All the cams and components turn fine. I took the valve cover off, and the cams are not broke, etc. All the valves move. I don't believe it is due to a bent valve, blown head gasket, or blown rings as it would be just too damn cooincidental and far out that it would happen to every single cylinder. I hope that this information is enough for some of you gear heads out there to recognize the problem and hopefully shoot me back a quick solution.
#84373, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 0 Jan-05-05 01:02 PM by XtremeRS
If the motor ran fine when the cams were not zeroed out, but ran like crap when you did zero them, I'm going to have to say the gears were not timing correctly to begin with, and now its way too far off. I'm not sure how many cam degrees it takes for the pistons to hit the valve faces, but I would assume you would hear that happening..I would not rule it out though. If it were me, I would take the adj gears off, and get your stock cam gear, and physically match up the timing marks, just to be sure they are exactly in the right spot. Then, put the adjustables back on, and keep them at 0, and set the timing as normal. If you have had around .008" taken off of the cylinder head, then that will get your gear marks off by around 1/4-1/2 tooth off. Always try to line up the marks perfectly though before adjusting the gear. Don't adjust the gear to compentsate for the timing marks being off, IF your cylinder head has not had any material removed from it,when initally setting the timing.
Also make sure your gear's center section did not "slip" and rotate from being too loose.
13.5 @108 MPH-2.2 60ft(stupid FWD!) S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential fuel injection) My webpage: http://eclipsed4evr.home.comcast.net -1998 Mitsubishi Eclipse RS-T- "Toy" -1992 Plymouth Laser Turbo AWD(SOLD) -2000 Honda CR-V(daily)
#84374, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 1
I only had the gears adjusted +1.5 degrees intake and -1 degree exhaust, so when I zeroed them, no way that could be the issue. However, the comment about the cam gear slipping too far is also what I thought could have happened. The cams are at zero now, and the timing marks line up. I just don't see how the cams would have got off time from the gear, i.e. the gear rotate somehow around the cam when they are keyed together. make since. any more input is greatly appreciated.
#84377, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 2
I would take off the cam gear bolt, and check the small dowel pins on the cams, to be sure one did not break off..I've seen it happen..Usually caused by insufficient bolt torque. Only thing I can think of at the moment..
13.5 @108 MPH-2.2 60ft(stupid FWD!) S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential fuel injection) My webpage: http://eclipsed4evr.home.comcast.net -1998 Mitsubishi Eclipse RS-T- "Toy" -1992 Plymouth Laser Turbo AWD(SOLD) -2000 Honda CR-V(daily)
#84421, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 4
That is most likely what I think that it is. I must have sheered a dowell. When you said that it is usually due to the bolt not being torqued enough kinda hit the spot also because I loosened that bolt up a bit to try and let the cam center itself in the journals. There was a ticking noise coming from the exhaust cam gear, when I tighened the bolt it got worse. Much worse. So I figured maybe I pulled the cam off center a bit or something causing something to hit. Crazy idea maybe, but when I loosened the bolt and tapped the cam in a little the ticking went completely away. The car ran fine, then just died, and now I think that one of the two cams is exactly somehow 180 degrees off.
I looked in the keyways, and noticed something in both before. Just to be sure what I am looking for, could you explain what I should be looking for just a bit? Also, if it is that keyway, is it possible to re-allign the cam, and replace that dowell with the belt on and cam still in the motor?
Thanks for your help by the way, it has been very appreciated and insightfull.
#84431, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 6
If the cam dowel broke, you bent valves. There are no ifs, ands, or buts about it.
Sorry dude.
______________________________ If a sentence found online has 35% misspellings or greater and includes at least two racially charged expletives, chances are it is a YouTube comment.
'95 Eclipse TurboGS (garage deco) '95 TSi AWD (restoring a survivor) '97 Talon ESi-T (poor impulse control) '99 Eclipse RS-T (daily beater) '13 Evo X (mostly stock) '17 Sienna (Middle Aged Dad Mobile)
#84433, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 5
Originally posted by bzoss That is most likely what I think that it is. I must have sheered a dowell. When you said that it is usually due to the bolt not being torqued enough kinda hit the spot also because I loosened that bolt up a bit to try and let the cam center itself in the journals. There was a ticking noise coming from the exhaust cam gear, when I tighened the bolt it got worse. Much worse. So I figured maybe I pulled the cam off center a bit or something causing something to hit. Crazy idea maybe, but when I loosened the bolt and tapped the cam in a little the ticking went completely away. The car ran fine, then just died, and now I think that one of the two cams is exactly somehow 180 degrees off. I looked in the keyways, and noticed something in both before. Just to be sure what I am looking for, could you explain what I should be looking for just a bit? Also, if it is that keyway, is it possible to re-allign the cam, and replace that dowell with the belt on and cam still in the motor? Thanks for your help by the way, it has been very appreciated and insightfull.
Just take off the cam gear, and on the gear will be a slot where a small roundish metal dowel fits into it. If that dowel is sheared off, then yeah, you may be in for some head pullin If the dowel is broke, then personally, I would not try to fix it, even though it maybe possible..I'm sure there are many guys on here who have a spare stock camshaft laying around. Just do NOT try and use a cam wihtout that dowel.
13.5 @108 MPH-2.2 60ft(stupid FWD!) S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential fuel injection) My webpage: http://eclipsed4evr.home.comcast.net -1998 Mitsubishi Eclipse RS-T- "Toy" -1992 Plymouth Laser Turbo AWD(SOLD) -2000 Honda CR-V(daily)
#84436, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 8
I would like to state why I did not bend any valves. I have forged pistons as well as a TTI racing head gasket. Not to confuse anyone here with the standard pistons/headgasket. I can't remember off hand if the forged pistons are shorter, or if they are just dished....*shrug* either way I was ok. If you have stock stuff then darkone is correct, you most likely bent the valves.
#84448, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 9
I have forged 10.5:1 compression JE pistons, any reason to believe that I would have messed up the pistons as well??
I also have crane stage II cams, not the stock ones . Looks like I am in for more than just a simple fix. the valves were 1mm oversized SS valves as well. I just did an entire performance rebuild with long rod kit, etc.
#84454, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 10
Originally posted by bzoss I have forged 10.5:1 compression JE pistons, any reason to believe that I would have messed up the pistons as well?? I also have crane stage II cams, not the stock ones . Looks like I am in for more than just a simple fix. the valves were 1mm oversized SS valves as well. I just did an entire performance rebuild with long rod kit, etc. keep the input coming, thanks for your help.
#84455, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 11
I am not ruling that out, I am going to do a leakdown test first thing tomorrow morning in order to determine that is what happened for sure. I am like you guys however, I think that is what happened, I just don't want to believe it right now. I am curious however if the pistons are going to be okay. I just rebuilt the entire engine about 1700miles ago. Put long rod kit in, 10.5:1 JE pistons full race port and polish, 1mm oversized SS valves, SBI lifters Crane springs, you see where this is going. In any case, it was very costly just for the parts, I did everything but the machining, and let me tell you it was a pain in the ass, and I do not want to have to do it all over again this soon. Once I see the full extent of the damage I might just cry. My car only ran for 3 weeks after the rebuild before I fucked it up.
#84456, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 12
Originally posted by bzoss I am not ruling that out, I am going to do a leakdown test first thing tomorrow morning in order to determine that is what happened for sure. I am like you guys however, I think that is what happened, I just don't want to believe it right now. I am curious however if the pistons are going to be okay. I just rebuilt the entire engine about 1700miles ago. Put long rod kit in, 10.5:1 JE pistons full race port and polish, 1mm oversized SS valves, SBI lifters Crane springs, you see where this is going. In any case, it was very costly just for the parts, I did everything but the machining, and let me tell you it was a pain in the ass, and I do not want to have to do it all over again this soon. Once I see the full extent of the damage I might just cry. My car only ran for 3 weeks after the rebuild before I fucked it up.
that sir, is very say to hear.
I would just start pulling the head off .
sometings in fuckered and......well.
yea.
I eat emo kids for breakfast
1995 Eagle Talon (SOLD) 72' SuperBeetle 72' Standard Beetle 56' Deluxe Beetle
#84477, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 13
GOOD NEWS!! Some of you might be startled to here this, I am very greatful to say the least. I ended up not bending any valves what so ever. My cam landed 180 degrees off. (Appx.) Any how, no valves were bent. I put the cam back in the proper position, did a compression test, and to my delight, compression numbers are as follows:
220-270-270-270
One thing that does have me boggled however, is the 220 in the first cylinder. I don't know if that ring has not seated yet, or...
Anyhow, I have 10.5:1 pistons from JE. I am curious if the valve recesses are what saved me from bringing valve to piston. In any case I am greatful.
So now where are your no ifs, ands, or buts eh?
I do appreciate the help however.
Maybe if you all have some insight on that first cylinders compression I could get it fixed. I am going to give it a few hundred more miles to let it break in a bit more then do the test again.
#84505, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 16
REALLY????
What numbers would you expect with 10.5:1 then??
I was under the impression that the stock compression numbers are around 180-200. Stock compression is 9.6:1. So shouldn't 280 be a good compression number?
Also, do you think that cylinder number one's low compression is due to the fact that it may not be seated just yet? I have total seal rings, and put ~1700 miles on the rings. I am a littled worried now because I just switched to full synthetic. Please help, I need to get these rings seated!!
Built block. Refinished head. Tuned suspension. TURBO.
#84527, "RE: Lost compression in EVERY cylinder, please help!" In response to Reply # 17
man....im so sorry! for some reason, when you said your comp #'s were in the 200's, i was thinking of 100's...thats why i said they were low for the compression you were running. so sorry for worrying you. got my #'s backwards. on the cyl. thats lower than all the others....do a leak down test on it to see if its the ring not seating properly.
1997 Silver RS Built T3/T4 BB Turbo 20psi Most current 1/8th mile time: 8.1@93mph 2.015 60' 1996 Black Supra TT 2004 Silver Snake
