Indrid cold Posted November 5, 2006 Share Posted November 5, 2006 1988 dl, EA-82, SPFI, NON-TURBO, 150K + miles (guess) Pressure test on engine: chilton says pull plugs, disconnect the cold start valve????? (w.t. heck), and coil wire, ... connect pressure test gauge, depress accelerator, crank and read... didn't know what the "cold start valve" was so just remove air filter house from top, pushed accelerator and did the deed... here are the numbers: .....................X (fan)................ #2....175 psi.......#1....162 psi #4....170 psi.......#3....152 psi so.... what do they mean? NO cold start valve on my wagon per later post. Soo... that answered that question as I was looking at Schematics in the chiltons and coudn't find it so I just pulled the air inlet boot off the top of the throttle body. Fuel pumping into cylenders possibly raising pressure test?... Yes there was a heavy fuel smell and was woundering about that since I did #3 twice and the second time was 20#'s higher... possibly didn't get a tight seal in the plug hole the first time...hmmmmm... may be a redo to double check. I think I will pull the fuse to the fuel pump and then test? and per another post...on the Throttle plate in my SPFI system...well... I don't think I have one of those.. kind of like the Cold start valve... I finaly gave up looking. I believe Throttle plate is assoc. with carberators? or am I missing something on that? Reply #2: General D., thanks for the info on the throttle plate... I will do another test next week and see if the numbers come in about the same. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted November 5, 2006 Share Posted November 5, 2006 Generally you want all your readings within about 10-15% of each other for a normal "everyday" use engine. So your lowest was 152, and highest was 175. That's a little over 13% difference which is acceptable but on the high end of the scale. It's not race engine acceptable, and it will do for a daily driver, but you should do some further tests to narrow down the source so you know what's starting to fail. You can try squirting about 1/4 ounce of oil in each cylinder and retesting. You'll likely find no improvment at all but if it does that indicates ring wear.... usually the cylinder sealing problems on the EA series are due to burnt exhaust valves and seats. You can pressurize the cylinder with shop air when it's at TDC on the compression stroke and listen to the exhuast, intake manifold, and oil fill tube to pinpoint the cylinder leaks to either intake or exhaust valves, or rings (unlikely). GD Link to comment Share on other sites More sharing options...
daeron Posted November 5, 2006 Share Posted November 5, 2006 okay, GD, just for clarification.. if you squirt oil into the cylinders, and the compression inproves in one problematic cylinder, that is.. an indication of ring wear, is it not? I ask for posterity's sake, because thats an excellent answer to his question, but its lacking that statement Link to comment Share on other sites More sharing options...
nkx Posted November 5, 2006 Share Posted November 5, 2006 im going to do this tomorrow, er, today. any other tricks or tips out there? im probably going to pull the fuse for the fuel pump before i start. Link to comment Share on other sites More sharing options...
ShawnW Posted November 5, 2006 Share Posted November 5, 2006 okay, GD, just for clarification.. if you squirt oil into the cylinders, and the compression inproves in one problematic cylinder, that is.. an indication of ring wear, is it not? I ask for posterity's sake, because thats an excellent answer to his question, but its lacking that statement Yes, that indicates ring wear. Id also say if you have an older battery by the time you test the 4th cyl the battery does contribute to the amt of indicated compression...if the 152 came from the last cylinder you tested then don't worry about it as that'd be 3% allocated to battery and really within 10 percent. So your numbers aren't bad was there a reason for testing the engine...I.E. poor performance lately or something? Link to comment Share on other sites More sharing options...
Indrid cold Posted November 5, 2006 Author Share Posted November 5, 2006 It is my daily driver... well kind of... more like my "Weekend Warrior Wagon!" just not much grrrrrrr to it not being lifted and all... but coming.. anyway... I am getting close to pulling the motor for a re-seal, so checking everything over. If compression is close enough and not to much power loss & or performance, I don't want to mess with the heads... I guess... just want to pull, re-seal, do clutch and back in... and run till she drops.... and stronger engine another day perhaps... I didn't put oil in the piston because of that same reason, seems valves fail long before the cylenders think about it... and if the rings are bad... will toss the motor anyway and get a stronger one... another day... Link to comment Share on other sites More sharing options...
daeron Posted November 5, 2006 Share Posted November 5, 2006 seems like it passes the buck. That is exactly what I thought, but since I have yet to actually do anything along these lines first-hand, on my own vehicle.. the knowledge is not as solid as what I know about what I _have_ done. That plus, GD worded that really really well.. short and sweet. it seems to me the sort of thread thats nice to find on a search for such information Link to comment Share on other sites More sharing options...
GeneralDisorder Posted November 5, 2006 Share Posted November 5, 2006 okay, GD, just for clarification.. if you squirt oil into the cylinders, and the compression inproves in one problematic cylinder, that is.. an indication of ring wear, is it not? I ask for posterity's sake, because thats an excellent answer to his question, but its lacking that statement Fixed! GD Link to comment Share on other sites More sharing options...
suberdave Posted November 5, 2006 Share Posted November 5, 2006 im going to guess you did you test in this order: #2, #4, #1, #3, and you did not unplug your cold start valve. as you did the test every time you turned you ign. from off to start. the cold start valve shot a little fuel into the cyl's. thus washing down the cyl. walls a bit with fuel and alowing som compression by the rings. this is why you should unplug the cold start valve. i bet if you would have checked #2 again at the end it would have been lower. you may have no problems... my thoughts, take them for what they are worth... about $0.02. -=Suberdave=- www.suberdave.com Link to comment Share on other sites More sharing options...
GeneralDisorder Posted November 5, 2006 Share Posted November 5, 2006 There is no cold start valve on an SPFI system. GD Link to comment Share on other sites More sharing options...
idosubaru Posted November 5, 2006 Share Posted November 5, 2006 those numbers look decent (not scarry at least), the variances may not be related to problems. i always do more than one test, make sure i'm getting consistent numbers. i thought stock they were only supposed to go up to 160? i think newer subaru's are in the 170/180 range but this is just from memory. i'm almost positive the only time i got 170/180 range compression on the EA82/ER27 (same pistons) is with motors leaking coolant in the cylinders from a blown headgasket. the coolant in the cylinders can bump the readings up somehow. was the throttle plate propped open? Link to comment Share on other sites More sharing options...
GeneralDisorder Posted November 5, 2006 Share Posted November 5, 2006 those numbers look decent (not scarry at least), the variances may not be related to problems. i always do more than one test, make sure i'm getting consistent numbers. i thought stock they were only supposed to go up to 160? i think newer subaru's are in the 170/180 range but this is just from memory. i'm almost positive the only time i got 170/180 range compression on the EA82/ER27 (same pistons) is with motors leaking coolant in the cylinders from a blown headgasket. the coolant in the cylinders can bump the readings up somehow. was the throttle plate propped open? I pulled around 200 - 220 off the EA81 that's in my wagon right now. I don't know how or why. As far as I know it's a stock 83 hydro lifter EA81 from an automatic coupe or sedan. Claimed to have been running on 3 cylinders due to some electrical issues. It sat for approximately 4 years in a shed and my garage before being put back to use. It's VERY strong and has great oil pressure (I did replace the pump).....FWIW. Then the EA81 in my Brat pulls 145 - 155 on every cylinder at 170,000 miles. I tore the engine down for a complete rebuild with performance cam and such due to some bad mains. The EA82 in my sedan is around 165 per cylinder after a recent head gasket change. The reading I've done sugests that for a standard road engine you should see psi in the range of about 17 to 20 times the value of the compression ratio. That gives a range of 161 - 190 for an EA82 SPFI with 9.5:1 comp. GD Link to comment Share on other sites More sharing options...
Indrid cold Posted November 5, 2006 Author Share Posted November 5, 2006 was the throttle plate propped open? looking at the chiltons, I don't find a Throttle plate on my SPFI (single point fuel injection)... so no I guess I didn't prop it open if I don't know what it is.... I think that is Carberator related not Fuel injection right? Link to comment Share on other sites More sharing options...
bgd73 Posted November 5, 2006 Share Posted November 5, 2006 Being cylinders get the same lube all the way around (there is a pun there ...) It leads me to ask about the integrity of the passenger side belt for #1 and #3. That is a big difference I simply could not blame on cylinders. 45psi oil is everywhere, 2 cylinders knocking off low on the same crank and pump, I would be blaming valvetrain timing/seat. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted November 6, 2006 Share Posted November 6, 2006 looking at the chiltons, I don't find a Throttle plate on my SPFI (single point fuel injection)... so no I guess I didn't prop it open if I don't know what it is.... I think that is Carberator related not Fuel injection right? Pushing the gas pedal to the floor while cranking opens the throttle plate all the way, and also puts the ECU into "flood clear" mode effectivly disabling the cold start enrichment. There is no cold start valve, only a single injector that the ECU uses to squirt more fuel durring cold starts. And yes, you do have a throttle plate. SPFI is also more commonly called TBI, or Throttle Body Injection. The injector sits right above the throttle plate, which is operated by the gas pedal just as it is on a carburetor. The only real difference between a carb and TBI is that the carb uses engine vacuum and a venturi to *suck* fuel from the float chamber into the engine - it relies on the venturi and jet sizes to proportion the amount of fuel correctly for the engine. The TBI uses a computer and a few sensors to control the amount of fuel, and rather than use engine vacuum to suck it in, it uses a high pressure electrically controlled injector to squirt the correct amount into the throttle assembly right above the throttle plate. GD Link to comment Share on other sites More sharing options...
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