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Showing results for tags 'compression'.
Found 8 results
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Hi all, EJ251 shortblock, EJ25 D heads, STI gaskets I'm getting an unbalanced shake/hesitation from 1800-2500 rpm. I can't effectively accelerate until rpms are above 2500. Taking off from a stop, the car feels bogged down. Plugs, Wires are less than a year old. Fuel pump/filter/strainer within 6 months. Coil and ignition module are within spec according to an FSM that I read. There was a vacuum leak with the purge solenoid under the intake manifold. It was not operating. Before I found that, my STFT, and LTFT indicated (at idle) 3-10%, and 18-25% respectively. After plugging the vacuum line I have the numbers seen in the photo below. I just did a leak-down test. According to the gauges, I'm within 10% for each cylinder. ALTHOUGH, I do hear/feel air escaping through the intake, and the oil filler tube. I followed this for instructions: I have also done multiple compression tests. For cylinder #3 is 225 psi, the remaining cylinders are between 210 and 215 psi. Can one cylinder being higher than the rest cause an unbalancing/misfire/poor low-end acceleration? Even if the numbers are good, the fact that I have air coming through the oil filler tube and intake, does this suggest the motor is shot? Check my timing again? Is there any change in timing instructions when mating an EJ251 with 25D heads? The heads are closer together, and the bolt holes for the intake manifold needed to be filed down a bit in order to properly bolt it onto the long-block. I've done a smoke test in/around the intake/intake manifold/hoses etc, and don't come up with anything. Thanks for the help, Greg
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Hi all, EJ251 block/EJ25D heads in '98 OBW, 5MT Recent work done in the past year: Plugs (ngk) wires (ngk) Timing belt kit (oem) Timing cam gears (oem) Cleaned and swapped out IACV Swapped out MAF Swapped out TPS New Fuel Pump, Strainer, Filter, Pressure Regulator New OEM Oxygen sensor Compression test cylinders 1-4: 214, 205, 225, 209 (unsure if these numbers are good for a High Compression build, it is consuming some oil. Maybe a half quart to full quart every few months of mostly short trips and some highway) I live in Las Vegas, and the temperatures are now at the usual hot. When city driving during the heat of the day, the engine will idle very low (has approached stalling, entire car shutters/shakes) and will often bob up and down +/- 100 rpm. It seems to be at its worse always when the fuel tank is at or below half-filled. If I use the A/C it helps with the issue because of the idle-up function. I've checked for vacuum leaks with a propane tank, and can't find anything. If I unplug a vacuum line, the engine idles up. Upon startup for the first 5 minutes, the exhaust smells very rich. Should I be looking to test next? The valves are kinda loud, should I do a leak-down test? When I press the accelerator pedal, from 1800 rpm to 2500 rpm, the motor behaves as if it is unbalanced. Anything above 2500, it is smooth and responsive. I am using an air intake from a '96 legacy wagon... is that an issue? Too restrictive? Any help would be appreciated. Greg
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EJ251/25D hybrid Original posting with backstory: timing belt jumped a few teeth headed up I-70 two days ago. Reset timing, and it runs well, but noticeable tick coming from the passenger side of the motor. That is the side that the belt skipped. Yet to do a compression test, but I wanted to know what my options are if a valve or two bent. I'm supposed to start grad school this coming Monday, and need to get from Denver to Las Vegas. I'm limited on time. If I don't fix the valves, what are the chances it eats the valves while driving down there? I know I can have a motor out and apart within 4 hours, but the time it takes to get parts and everything needed gets me down to the wire on being at school on time. If I can at least get it to Nevada, I have a garage that'll allow me time to fix it properly... Thoughts?
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So I just put a new timing set on my 86 GL-10 4WD Wagon and it won't start. I'm 95% sure the timing belts are on right. The car has fuel, spark, equal compression in all four cylinders, and the ignition timing is spot on. I pulled the intake off and cranked it over and there was air coming out of the intake on the compression stroke. Does anyone know if this is just a valve timing issue or something else?
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Dropped my WRX off at the Subaru dealer service center to get a diagnostics on an existing issue. Check Engine light comes on and engine codes read that all cylinders are misfiring. It started w/ #2 about two years ago, repair shop replaced the spark plugs. One month later, engine codes come back w/ cylinder 2. Eventually I get all 4 cylinders misfiring over a period of one year. Back to the diagnostics, the service techs ran a compression test on #2 and they said the compression was very low (I didn't write it down). How ever, after a little bit of research it seems like it could be a valve issue or more then likely a piston issue. Ether way its going to cost 5,000+ to fix. I looked at what a new motor would cost and Subaru can swap the motor they built for 8,400. Looking at Motion Labs http://www.motionlabtuning.com/services/pro-built-engines/subaru-pro-built-engines/ they sell a motor for 2,999 and after getting the complete set up its 3,800 or so. If you've got an engine from them or another site, please comment. What I'm wondering is if its worth putting that much money into this car? The two passenger doors need to be fixed, I scrapped a rail road tie a few years ago. I can use insurance to fix that for 500. Needs a new windsheild. KBB says its work 8,100 - 9,000 in "fair" condition, and the most it could be worth is 11,000 - 12,000. With repairs ranging 5,000 - 8,400 does anyone think its worth putting that kind of money into it. It will show an accident on car fax. Any tips would be great! My guess is that there might be someone who will pay 12,000 for a 2008 WRX with a brand new motor and the body being fixed up. -
Hey everyone, My 87 'Rally Wagon' had recently started showing signs of HG failure (frothy coolant & coolant loss) so I pulled the engine and found that it was just my heads that were toast... so, I've decided to keep my low compression block (7.7:1) for a spare and I'm putting the old heads onto an XT block for fun(: the XT engine-(MPFI 9.5:1 comp) What I want to know about this is if there's anything other than the obvious dangers of running boost with high compression.. if anybody has built one of these and run it dependably for any amount of time, what did you do? What should I look out for? And what's the most common failure point of these? This is my test engine, and if I like it I'm going to build a fresh block, ported heads, ported turbo, and eventually a propane set-up Thanks everyone for any input, I'm not expecting anything more than a mass amout of power and eventually a big bang over time with this one haha(: but id like to delay the bang until I get it all running right
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Hellloooo USMB. First off, thanks for all the advice on here. I've been lurking for awhile, probably should have posted something earlier but anyway... like before I bought this flesh-colored wagon. 1987 GL wagon, carbed, Hi Lo tranny and 125,480 miles and lots of...let's call it character so I don't start swearing lol. First mistake-- didn't drive it much, towed it home. Replaced (new parts) water pump (old one dead) timing belts plugs (NGK R) Wires Dist Rotor Battery Has 1/4 or so new gas with a bit of sea foam Used Weber DGAV 32/36 Carb, trans-dapt mounting plate, 130/130 jets. No choke. Doesn't have air filter on it meow. I've also ripped out the interior and cleaned out the critters' collection). Sheesh that was a PITA. It seems that either engine mounts were sheared or the bolts fell off?? One of them doesn't line up. There's a bit of crumple around the hood zone, and no grill. I did some compression tests, and they are loooow. ($25 Harbor Freight tool) I tried to give each cyl 10 cranks, and did each three times. Removed all plugs. Didn't do wet test, from what I've read (source:internet) boxxer engine doesn't give best results for that? I can probably figure it out if y'all think I ought to tho. 3-70, 60, 75 psi 4- 70, 80, 80 psi 1- 80, 60, 70 psi 2- 70, 70, 80 psi This was warm. (I also did the same test cold (like at 40 degrees) and they were all 100-110 psi what gives?? I did procedure same same, maybe there was moisture in there, it had been sitting for awhile?) Also, if I keep cranking, it will keep going 100+, but doesn't jump a whole lot the first crank, 10-20psi. If I let it idle, it will eventually stall out with fouled plugs after 15-20 minutes. With clean plugs, when I run it at 3500 or so rpm for a few minutes (in neutral, it ain't regstrd yet), the plugs look like this--(left to right 1,2,3,4 cylinder) Odd, no? The #2 looks healthy, but the others are blackened. I guess "fluffy" describes it. If it won't start, it has been bc plugs are fouled, and #3 has been wet fouled. This is what I think, but I the stump has been chumped, and I would like your input. 1. The carb needs adjusting. There may be a small vac leak. The idle mixture screw doesn't seem to make much difference, although I think I can hear a sucking sound when I screw it all the way in (idle screw in = less gas for idle?) 2. The engine needs a rebuild, and the plugs will continue to foul until that is done. Headgaskets came to mind? but the exhaust doesn't smell sweet by any means. It blows out a bit of white exhaust I guess. I have had to fill the coolant, but I figured that was just the cooling system filling in? Something to keep an eye on anyhow. me--> What do you think? Is there any other info I can provide? All input is welcome! I appreciate all your knowledge and have learned a ton lurking. Thanks A Bend, OR (ps hope the images are large enough, they look small in preview...)
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Thanks as always for the help. Love these forums. On my 1999 Legacy Outback (2.5L DOHC), I recently replaced my timing belt & components after a slipped tooth resulted in poor compression and misfires on cylinders 1 and 3. Before the timing belt replacement I got 90 and 80 psi compression on cylinders 1 and 3, respectively. Now I get 210 and 60 psi respectively. (On cylinders 2 and 4 I got 190 and 180). I detailed this info in this thread. A friend advised a leakdown test next. I put Cylinder 3 in TDC, held it in place with a socket and breaker bar, dialed input pressure up to 75 psi and got 72-73 on the other gauge, i.e. approximately 3-4% leakage. I could hear a quiet hissing through the oil fill cap. 1) Do these numbers seem right---i.e. are the results of my leakdown test consistent with the compression test? Want to make sure I'm doing it right. 2) Assuming it is right, this means I have worn piston rings or cylinder walls, right?
