samneric Posted June 6, 2008 Share Posted June 6, 2008 Hey all, I have a Hitachi dissy on my Hitachi carbed 4WD Brat. Been working on my A/C system and whenever I engage the compressor, the timing retards to after TDC, the engine runs rough then dies. I confirmed this with a timing light. This happens *every* time. I thought it was a dieing compressor so I switched in the one (and all the brackets :-\) from my spare Brat. When this happens I have to unscrew the dissy mounting bolt, lift the dissy, advance the rotor by one tooth and re-setup the timing. This can't be normal and was wondering if anyone else has had issues with a distributer losing its timing?? I hope this is a dissy issue and not the dissy drive gear on the crankshaft. Pulling the engine again after 3 months of solid work on the car is definately surplus to my personal requirements.... Steve Quote Link to comment Share on other sites More sharing options...
samneric Posted June 6, 2008 Author Share Posted June 6, 2008 Update - This afternoon, I swapped in another of the 4 dissys I have. The compressor ran longer this time but the timing went again. I took some notes of the dimensions of three that are off cars at the mo. They all pretty much measured up except the model number of the one I pulled out today is D4R80-03 1Z04, where the other two (one I put back in) are D4R83-12 xxxx and D4R83-13 xxxx. I'm at the point now where I suspect the worm gear on the crank is worn or the crankshaft bearings are loose which causes it to move enough under load that the dissy jumps a tooth. Next task - swap in the block/heads from my spare Brat - it apparantly has less miles on it. Steve Quote Link to comment Share on other sites More sharing options...
Gloyale Posted June 8, 2008 Share Posted June 8, 2008 Are you setting you're base timing with the Advance disconnected and plugged??? If not, then you're base timing is actually being held advanced by the vac. Combine that with an idle up solenoid that is leaking vacuum. When you activate the AC, the solenoid is sent vacuum but then leaks it all out. Overall vac drops and you're timing retards??? Just a speculative train of though. Quote Link to comment Share on other sites More sharing options...
samneric Posted June 8, 2008 Author Share Posted June 8, 2008 When you activate the AC, the solenoid is sent vacuum but then leaks it all out. Overall vac drops and you're timing retards??? That is a good point. I have disconnected the vacuum line from the solenoid but not plugged it. I will plug it up and try again. I still need to advance the dissy one tooth and set it up again - haven't had the inclination this weekend - been driving Miss Daisy (my girlfriend in her car ) since my last attempt. I do set up the timing with the vac advance disconnected and plugged. To be honest though, when it is connected and the engine is idling, it doesn't make much difference to the advance. It sure is a wierd situation because I literally do have to advance the dissy one tooth after it happens. The engine will run fine, the revs will drop a little when the comp is first engaged then after a while, the engine just drops and dies after the tooth is jumped. Switching off the A/C and restarting the engine doesn't cure it, only advancing the dissy one tooth will get the firing point back in the adjustment range of the dissy body. Steve Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted June 8, 2008 Share Posted June 8, 2008 That makes no sense at all. First - just driving the car is a heavier load than the AC compressor. That alone should be enough to cause this problem if it were a "load induced tooth skip" as you surmise. Second - have you seen the distributor drive "gear" on an EA81 crank? It's a gear in the strictest sense of the term, but the "teeth" would be near impossible to break off as they are close to vertical, very long, and quite deep. Shine a light down in there and look if you can. Something isn't right, but the AC compressor is just a load on the engine. Just like everything else (clutch/transmission, alternator, etc). Turning the AC compressor on while idleing at a stop is a much smaller load than driving the car forward from a stop. If this ONLY happens when the AC is turned on and not when driving the car then it certainly is not a load induced change. GD Quote Link to comment Share on other sites More sharing options...
samneric Posted June 8, 2008 Author Share Posted June 8, 2008 That makes no sense at all.GD I conquor. It is strange. Second - have you seen the distributor drive "gear" on an EA81 crank? GD Yes, it looks like a worm gear to me (one single "tooth" in a spiral along its length). I'm at a loss as to why (at 8 d btdc) I would have to pull the dissy shaft out, rotate it anti-clockwise one tooth position and re-seat it so that the rotor points back at the #1 pickup. My suggestion is that somehow the dissy gear (driven) is lifting off the worm gear and dropped back one tooth out. I know it sounds hard to beleive but those are the symptoms I experience.... Steve Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted June 8, 2008 Share Posted June 8, 2008 My suggestion is that somehow the dissy gear (driven) is lifting off the worm gear and dropped back one tooth out. I know it sounds hard to beleive but those are the symptoms I experience.... Only way I could see it happening is if the distributor drive gear were spinning on the crank. That would require the key to be sheered away. Unlikely to say the least. Is the crank pulley bolt tight? Now that I look at an EA81 crank I have sitting here there is not much key holding the drive gear from spinning. What you may have is either no key, or a sheered key. When the AC kicks on, the belt pulley is spinning on the crank and the drive gear is spinning with it. GD Quote Link to comment Share on other sites More sharing options...
samneric Posted June 8, 2008 Author Share Posted June 8, 2008 Only way I could see it happening is if the distributor drive gear were spinning on the crank. That would require the key to be sheered away. Unlikely to say the least. Is the crank pulley bolt tight? Now that I look at an EA81 crank I have sitting here there is not much key holding the drive gear from spinning. What you may have is either no key, or a sheered key. When the AC kicks on, the belt pulley is spinning on the crank and the drive gear is spinning with it. GD Not sure how tight the crank pulley bolt is - although I have been using a socket and wrench on it to turn the motor over (backwards and forwards) to get the timing marks alligned. Could it be a loose pulley bolt allowing the drive gear to move forward and back on the crankshaft ?!?!? Steve Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted June 8, 2008 Share Posted June 8, 2008 Could it be a loose pulley bolt allowing the drive gear to move forward and back on the crankshaft ?!?!? Yes, but I'll lay odds the key is missing or sheared away. If the crank pulley were spinning it could easily spin the gear as well - they both use the same small key. If someone didn't tighten the bolt enough then kicked the AC compressor on a few times..... it wouldn't take much judging by the size of the key. It's not designed for that kind of load. I would take the pulley off and investigate. Good time to replace the front crank seal also. Only takes 20 minutes or so to pull it off and put it back. GD Quote Link to comment Share on other sites More sharing options...
samneric Posted June 9, 2008 Author Share Posted June 9, 2008 Yes, but I'll lay odds the key is missing or sheared away. If the crank pulley were spinning it could easily spin the gear as well - they both use the same small key. If someone didn't tighten the bolt enough then kicked the AC compressor on a few times..... it wouldn't take much judging by the size of the key. It's not designed for that kind of load. I would take the pulley off and investigate. Good time to replace the front crank seal also. Only takes 20 minutes or so to pull it off and put it back. GD You've hit the nail on my head..... I don't believe this.... After 3 months of work on my engine.... Closer.... That blows me away. The bolt was torqued up one fraction off 54 ftlbs given a range of 47-54. It must have been the tight (it wasn't completely seized) compressor that caused it. Maybe these (Aluminium - HAH!) crankshafts lose their strength after 200k miles..... I'm under the moon. Steve Quote Link to comment Share on other sites More sharing options...
Gloyale Posted June 9, 2008 Share Posted June 9, 2008 wow, that's some crazy stuff there. GD sure knows the EA81 don't he. now how to fix it??? Do you think it will be possible to put a new woodruff key in? or is the crank Fubar?? Oh, BTW, they(the cranks) aren't aluminum, but I think you know and where joking, I hope. Quote Link to comment Share on other sites More sharing options...
samneric Posted June 9, 2008 Author Share Posted June 9, 2008 wow, that's some crazy stuff there. GD sure knows the EA81 don't he. now how to fix it??? Do you think it will be possible to put a new woodruff key in? or is the crank Fubar?? Oh, BTW, they(the cranks) aren't aluminum, but I think you know and where joking, I hope. I imagine that the crank is fubar. At the very least, I will have to pull the motor again to add a key, not to mention all those iron fillings sifting around the engine system.. I didn't know that crank was not aluminum. I guess its steel then. Steve Quote Link to comment Share on other sites More sharing options...
samneric Posted June 9, 2008 Author Share Posted June 9, 2008 wow, that's some crazy stuff there. GD sure knows the EA81 don't he. now how to fix it??? Do you think it will be possible to put a new woodruff key in? or is the crank Fubar?? Oh, BTW, they(the cranks) aren't aluminum, but I think you know and where joking, I hope. Hang on a minute....... After searching the forum and discovering that the key isn't machined into the shaft (which I have seen before), dusting off my cobwebs now I DO remember something crescent shaped on the floor after replacing that front oil seal...... Lucky I kept it just incase I came to need it in the future Now let me go and slap this guy back in :-\ My ignorance is really starting to show through - I'm embarressed. Steve Quote Link to comment Share on other sites More sharing options...
samneric Posted June 9, 2008 Author Share Posted June 9, 2008 Alrighty, this looks a little better.... Thanks GD for the help! Closer... So its running - WITH AC! :banana: :banana: Which leads me on to my next thread.... http://www.ultimatesubaru.org/forum/showthread.php?p=741712#post741712 Steve Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted June 10, 2008 Share Posted June 10, 2008 Cool - that looks much better now. Glad it didn't actually shear it off - that would be the first failure of that kind I have seen. Our faith in the EA81 is preserved. GD Quote Link to comment Share on other sites More sharing options...
zukiru Posted June 10, 2008 Share Posted June 10, 2008 that was a cool read! thanks! Quote Link to comment Share on other sites More sharing options...
zstalker Posted June 11, 2008 Share Posted June 11, 2008 somewhat related to this, it would take a heck of a lot more torque on the crank pulley than 54 ft/lb to hold the distributor drive gear by pulley pressure tension alone. The Suzuki Verona, which I have the distinct displeasure of working on, has a torque specification of well over 400 ft/lb, and it drives the timing chain and the oil pump by tension from the dampener pulley alone. really retarded idea... seriously. just a thought I had that makes me thankful Subaru uses easily worked with and reliable woodruf key. ~Erik~ Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted June 11, 2008 Share Posted June 11, 2008 really retarded idea... seriously. It might sound that way at first but really think about it... 1. No special machining required. 2. No key to fail, shear, drop on the garage floor. 3. No keyway in the gear or pulley to be mangled or develop a finger-slicing sharp edge. 4. Cheap and simple to manufacture. All you need is a big-rump roast wrench? Sound awesome to me! Although the EA81's got it beat in the timing department. Timing GEAR's. Chains are good, but gears are better. GD Quote Link to comment Share on other sites More sharing options...
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