Doug_ATX Posted May 25, 2009 Share Posted May 25, 2009 Hello all, I'm new to Subaru's but now have an 83 BRAT 4WD. It was pretty neglected and needed have the front suspension repaired among other things-the top strut mounts separated and the struts fell into the wheel wells (I think the PO drove like this for a while since they were pretty well hammered!) The parts were pretty hard to find :-\ But, the engine ran well and the rust wasn't *too* bad, so I picked it up for cheap and I LOVE it ! Anyhow I have a few questions. As far as I can tell from the o-so-helpful haynes manual, I have the 1800 E-81 engine with the Hitachi 2bbl. It appears (although I'm not sure) that all were the 'feedback' type carb with an ECU under the dash controlling the afr via some means I'm still a little unclear on. I was a little surprised to see that it would offer a limited array of trouble codes and it piqued my interest. So I pulled the panel where the ECU should be, and its GONE! I can see clearly where the PO cut a little window to easily see the light through the panel, so I'm confident there was one there. Under the hood it looks like the EGR, canister purge, air injection, heat riser and a host of other things have been disconnected. So the question is: is this common? detrimental? easily repaired (or worth reparing) I know with some other vehicles I owned a disconnected EGR could lead to some other problems. I'm aware of the legality/patchouli issues, so no need to mention that The car was at ~5k ft altitude, and is now at sea level. I was surprised at how well it ran at both altitudes and since I cant see any way to adjust the mixture I assumed the ECU made some pro adjustments. Now that I know its not doing anything (since its just an empty bracket now) is there a way to manually adjust the carb? The e-81 looks like a fun engine and reminds me of my general aviation days. Any other suggestions for a newbie about the BRAT are appreciated! Thanks in advance! Quote Link to comment Share on other sites More sharing options...
edrach Posted May 25, 2009 Share Posted May 25, 2009 Welcome to a small but proud and elite Brat Owner's group. You're off to a good start. Firstly, I would suggest the How to Keep Your Subaru Alive book by Larry Owens, Volume 1 should work for you although Volume 2 just added a few more years to the copy. Amazon or Ebay should find it for you and it is much more useful and entertaining than the Haynes manual. There are even some on the USMB who can get you a copy on CD or download it to you. Sorry I can't help you about the missing ECU although there might be one at Pull a Part (they currently have a gen2 Brat in the yard). I wouldn't worry about the EGR; I've had mine disconnected for 5 years now since I put the Weber in place of the Hitachi (a fine upgrade) and aside from the ECU telling me the EGR is not there it hasn't presented any difficulties. Best of luck and welcome the the USMB, Quote Link to comment Share on other sites More sharing options...
Twitch de la Brat Posted May 25, 2009 Share Posted May 25, 2009 Congrat on the purchase! I have an 85 and loooove it to death. Oh, the engine is referred to as the EA81, on here it is anyway. :-p Now I must ask, do you have the 4speed dual range 4x4, aka 4sp d/r, the 4 speed single range, aka 4sp s/r, or the 3 speed automatic, aka 3AT? And as iterated by Ed, welcome to the USMB. You will find much more info on here than you could probably ever use Twitch Quote Link to comment Share on other sites More sharing options...
ihscout54 Posted May 25, 2009 Share Posted May 25, 2009 I cant say about the '83 BRAT for sure but I have seen EA81 vehicles that were non-feedback. All you need to do if it was feedback is rejet the carb like a non-feedback, and yank the solenoids and plug the port they were hooked too. If your car has an O2 sensor in the cat, odds are good it is/was a feedback model. But who knows what was done to it over the years, alot of people dont understand how a system works and when they have a problem the pull and plug everything. The components you listed as being disconnected werent controlled but the feedback computer anyways. I would hook the EGR valve back up and get it back in the mix (but thats just me). If you have to pass emissions you will be sorting out what the previous guy did for a bit. If not just make sure there are no open lines or leaks. Quote Link to comment Share on other sites More sharing options...
Doug_ATX Posted May 25, 2009 Author Share Posted May 25, 2009 (edited) Thanks for the replies! Edrach- I will definitely get the book you suggested. I had a feeling that the weber (I've owned weber carbs) would be be better than Hitachi (My VCR manufacturer). But the Hitachi carb was just rebuilt and it looks like they did what ihscout54 suggested as far as making it work w/o the ECU. It really does run remarkably well. Maybe it was running way rich up in the mountains /shrug Twitch- Its a 4sp d/r (thanks for getting me going on the pro lingo ) ihscout54- I too would rather have the EGR functioning properly, but I'm unlikely to spend money to get fixed, particularly if I don't run into any complications from it being disconnected. The PO looks like they did just what you described and pulled and plugged everything when they rebuilt the carb. I don't think he rebuilt it himself, thank god, judging from some of his other "repairs." He was also a cheeto, corn nut, and MRE peanut butter fan, as well as a messy eater. State inspections wont be a problem. Out of curiosity, how did the feedback system control the afr? I understand the sensors, and inputs, but I still dont understand how it attempted to change the afr. Was it constricting/increasing airflow? Or did it have control over fuel? All of my carbd vehicles in the past were pre-emissions tech. Edited May 25, 2009 by Doug_ATX clarify question Quote Link to comment Share on other sites More sharing options...
Durania Posted May 26, 2009 Share Posted May 26, 2009 We need BRAT pics. Quote Link to comment Share on other sites More sharing options...
Doug_ATX Posted May 26, 2009 Author Share Posted May 26, 2009 We need BRAT pics. hehe, I will take some next week when Im back in town... shes not that pretty I will warn you! I sprayed it down at the local car wash and I swear it doesn't look ANY cleaner, despite the mudflow the wash produced. I will say though, these are the first t-tops I've ever seen that don't leak profusely. +1 Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted May 26, 2009 Share Posted May 26, 2009 Out of curiosity, how did the feedback system control the afr? I understand the sensors, and inputs, but I still dont understand how it attempted to change the afr. Was it constricting/increasing airflow? Or did it have control over fuel? All of my carbd vehicles in the past were pre-emissions tech. I suppose since I'm the closest thing to a resident expert on the feedback carbs I can take a crack at giving you a rundown of the system. The feedback system incorporates primarily only two sensors (although later EA82 systems used more). The primary sensor it uses is the O2 sensor (narrow-band of course). Ancillery to that is the coolant temp sensor. Beyond the sensors there are two duty solenoids that control air-flow to the air-bleed's of the carb. The duty solenoids operate in a continuous feedback loop with the O2 sensor - the computer interprets a rich or lean signal from the O2 and uses a sqaure wave signal to rapidly turn the duty solenoids on and off. The frequency with which they turn on and off determines the amount of air allowed through them and to the air-bleeds in the carb. Carefully setup, it can control the air/fuel ratio surprisingly well. Unfortunately there are many drawbacks. For one the jetting of the carb has to be set rich so that the duty solenoids can lean it out by restricting flow. When they cease to function or are removed the result is horrible fuel mileage. Additionally, repair parts and obscenely expensive and it really doesn't perform that much better than a standard non-feedback carb. Maybe 1 or 2 mpg - if that. Besides the direct problems related to the system, the fact that they used the exact same carb on non-feedback models means that the whole lot of them are built with these metering ports for the modification of the air-fuel ratio. On the non-feedback models they are still used! The system is complex and uses vacuum valves to direct airflow through the metering ports under different throttle conditions. Basically what I can tell you after many years of messing with these carbs is that eventually my understanding of them led me to toss them all in the dumpster and go with better forms of fuel management. First the Weber (which is nice and simple), and more recently I did a whole write up about converting the EA81 to run on the EA82's throttle body fuel injection. You can read it here: http://home.comcast.net/~trilinear/EA81_SPFI.html GD Quote Link to comment Share on other sites More sharing options...
TomRhere Posted May 26, 2009 Share Posted May 26, 2009 Welcome to the Board.... The HTKYSA book Edrach mentioned is a real good source of info. I have a CD version of it, and use it if I can't find info elsewhere. Another source of info for you, http://mshoup.us/docs/fsm/EA81/83/ Quote Link to comment Share on other sites More sharing options...
'84 Flat-Four Posted May 27, 2009 Share Posted May 27, 2009 All hail Baccaruda for this link... http://www.worldwidecm.com/HTKYSA.pdf Quote Link to comment Share on other sites More sharing options...
TomRhere Posted May 28, 2009 Share Posted May 28, 2009 All hail Baccaruda for this link... http://www.worldwidecm.com/HTKYSA.pdf Many thanks..... All the links I had, never worked, this one does... Quote Link to comment Share on other sites More sharing options...
Doug_ATX Posted May 31, 2009 Author Share Posted May 31, 2009 We need BRAT pics. Still too lazy to take new pics, but here is one from the sale listing. Quote Link to comment Share on other sites More sharing options...
Durania Posted May 31, 2009 Share Posted May 31, 2009 BRATs look so good with tinted windows. Can't wait to see more. Quote Link to comment Share on other sites More sharing options...
'84 Flat-Four Posted June 1, 2009 Share Posted June 1, 2009 looks good... is that a tonoeau (spelling?) cover in the back? Quote Link to comment Share on other sites More sharing options...
Twitch de la Brat Posted June 1, 2009 Share Posted June 1, 2009 looks good... is that a tonoeau (spelling?) cover in the back? Clean lookin' BRAT my man. That has got to be the least stickered BRAT, I have ever seen. No stripes, no sport badging, not even a pinstripe. And btw, Fred, its spelled Tonneau. Sorry, I felt like being the spelling police tonight. Twitch Quote Link to comment Share on other sites More sharing options...
'84 Flat-Four Posted June 1, 2009 Share Posted June 1, 2009 Thanks Twitch! And btw, I don't know what the heck I was seeing when I posted that... must have been the poor lighting on my laptop... but now that I'm looking at it on my desktop... there's nothing back there (i swear i was sober when i posted:drunk:) Quote Link to comment Share on other sites More sharing options...
gwilson87 Posted June 2, 2009 Share Posted June 2, 2009 Here is my brat helping shuttle some bikes up the mountain. Only owned her few a few weeks and am making the plans for the EJ22 swap... *If I can find a proper donor...* Quote Link to comment Share on other sites More sharing options...
Twitch de la Brat Posted June 2, 2009 Share Posted June 2, 2009 Hold on... Is that stickerage original? Or a Pooparu or McBrat job? Cuz that weren't there in the other pic... Twitch Quote Link to comment Share on other sites More sharing options...
gwilson87 Posted June 2, 2009 Share Posted June 2, 2009 Sorry, my stickers are original *as far as I know*. I was reading the post and someone said they wanted more brat pics. And since I too am a new brat owner I threw my pic up for the viewing pleasure of those out there. Doug_ATX's brat doesn't look like it had the stickers. Quote Link to comment Share on other sites More sharing options...
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