Scoby4wd Posted December 14, 2020 Share Posted December 14, 2020 (edited) Hey guys, I just recently refinished rehabbing an EA82T that was mixing coolant and oil, in my Black '89 RX. I put in reman heads, new HG's, all engine seals, cooling system, clutch etc. The car/motor have 80k miles. This past weekend I put the motor back in and she is running very nice. Only issue is that it seems to overboost in 2nd, 3rd at high RPMs at WOT and then the ECU cuts fuel. It also tends to ping a bit right before this happens. Mid throttle gets very nice pull through all gears with no pinging. Does seem a bit laggy under 3K but I assume thats the nature of the beast. Its a bone stock EA82T with the exception of a 2.5" custom exhaust header to muffler with no cats. My wastegate is free but I haven't tested to see that its opening yet. Other than the wastegate not opening, I'm thinking the issue is probably due to the exhaust being too free flowing. Thoughts on this? Thanks John Edited December 14, 2020 by Scoby4wd Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 14, 2020 Share Posted December 14, 2020 Likely due to unrestricted exhaust. At this point you either need to restrict it, or port the wastegate till you solve the boost creep. GD Quote Link to comment Share on other sites More sharing options...
carfreak85 Posted December 14, 2020 Share Posted December 14, 2020 I've not played with my EA82T very much yet, still need to sort some codes before I start driving it hard. On my EA81T (custom SS header, catless 3" downpipe, 2" exhaust w/ Flowmaster muffler, stock otherwise) I've never had an issue with overboosting. Boost starts building at 1,250 rpm and I've got the full 7 psi by 2,000 rpm, so no real turbo lag to speak of. 1 Quote Link to comment Share on other sites More sharing options...
Scoby4wd Posted December 14, 2020 Author Share Posted December 14, 2020 1 hour ago, GeneralDisorder said: Likely due to unrestricted exhaust. At this point you either need to restrict it, or port the wastegate till you solve the boost creep. GD Thanks. I have a 2.5" cat in my stash, Ill add that to the down pipe I guess to see if it helps. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 14, 2020 Share Posted December 14, 2020 We run into boost creep from time to time. It's not a sure thing that any one specific combo will experience it. It depends a lot on the flow of the specific turbine casting in the wastegate area. Some are better than others - in stock form they flow enough, but with unrestricted exhaust some wastegate ports can't flow enough to prevent the boost from climbing even when fully open. GD Quote Link to comment Share on other sites More sharing options...
Step-a-toe Posted December 15, 2020 Share Posted December 15, 2020 Seems to over boost.... Some numbers would be beneficial It is interesting to hear pinging just before feeling knock circuit cut in as I see my knock control monitor reading. If yours was a Series One flapper, you could *cough* disconnect over boost solenoid to see if it is your problem Quote Link to comment Share on other sites More sharing options...
Scoby4wd Posted December 15, 2020 Author Share Posted December 15, 2020 (edited) Mine is the later version Edited December 15, 2020 by Scoby4wd Quote Link to comment Share on other sites More sharing options...
Scoby4wd Posted December 17, 2020 Author Share Posted December 17, 2020 Anyone know how I can test that the wastegate is actually opening? Kind of hard to see while you are driving the car Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 17, 2020 Share Posted December 17, 2020 You can use a hand pump like a mityvac to test the actuator. And you can just plumb it directly to the compressor housing with a section of straight vacuum line and that should open the wastegate at 5-7 psi. GD Quote Link to comment Share on other sites More sharing options...
Step-a-toe Posted December 18, 2020 Share Posted December 18, 2020 Can. You. Install. A. Boost. Gauge. ? To. Use. As. A. Diagnostic. Tool Quote Link to comment Share on other sites More sharing options...
Scoby4wd Posted December 22, 2020 Author Share Posted December 22, 2020 Wastegate actuator seems to be functional based on my testing with a vacuum pump. Im going to be installing a boost gouge today and then I can hopefully get some real numbers. Quote Link to comment Share on other sites More sharing options...
Scoby4wd Posted December 25, 2020 Author Share Posted December 25, 2020 Installed an Autometer mechanical boost guage today. I can see that it cuts fuel when the car hits about 15psi on the guage, so I am definetely overboosting. I have a cat here, going to install that into the exhaust this week. 1 Quote Link to comment Share on other sites More sharing options...
john in KY Posted December 26, 2020 Share Posted December 26, 2020 I doubt that will change anything. My thought is the waste gate controller is not "seeing" enough vacuum. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 26, 2020 Share Posted December 26, 2020 59 minutes ago, john in KY said: I doubt that will change anything. My thought is the waste gate controller is not "seeing" enough vacuum. Pressure. The wastegate actuator works on pressure. About 7 psi. GD 1 Quote Link to comment Share on other sites More sharing options...
nigxl Posted December 28, 2020 Share Posted December 28, 2020 I've also just got mine running after a few years of being laid up. Same engine and same issues, oil and water mixed but mine was down to a freeze plug. Mine failed to start initially and I soon found that the fuel pump wasn't getting voltage when connected up. Long story short I found a video on youtube where a guy was having voltage problems at his pump and found a cure was to basically jump the pump control wire to a good earth and bypass the ecu. Mine is now running under it's own steam for the first time. Just a thought if you are having fuel cut issues. Quote Link to comment Share on other sites More sharing options...
Scoby4wd Posted December 30, 2020 Author Share Posted December 30, 2020 (edited) So I figured this out finally. Turns out my waste gate duty solenoid (on the passenger strut tower) doesnt seem to be doing its job. I tested this by directly connecting the turbo pressure outlet straight to the wastegate actuator. When I did this I got peak boost of 6.5 psi reliably and no pinging. The car ran and drove beautifully. I am thinking the right move here is to remove the WGDS but keep the harness connected since it seems to throw a CEL when disconnected and just plug any open vacuum ports. I could even add a manual boost controller and up it to 8 or 9 psi, but frankly I'm not inclined to mess with this motor too much. Alternately, I am wondering if perhaps its just not connected properly and was wondering if someone could tell me which vacuum connections go where. I tried two different valves (happened to have a second one) and neither were controlling boost. I did test both by connecting them to 12v and listening for a click, which it did. Edited December 30, 2020 by Scoby4wd 1 Quote Link to comment Share on other sites More sharing options...
Scoby4wd Posted December 30, 2020 Author Share Posted December 30, 2020 (edited) Found a great youtube video about the wgds Edited December 30, 2020 by Scoby4wd Quote Link to comment Share on other sites More sharing options...
Scoby4wd Posted December 30, 2020 Author Share Posted December 30, 2020 (edited) Final update, got this thing totally sorted out. I got the WGDS working finally, but in the end eliminated it. First a big thanks to all who posted here to help me get it done. You guys definitely helped me quite a bit. So now to the solution. First, I found that two of the lines going to the WGDS were crossed by one of the previous owners. Funny thing, the first time I worked on it I found one of the clamps about 1" down the hose which I found odd - so definitely someone had messed with it and plugged the two larger connections in wrong. On my test drive with the WGDS hooked up correctly I noticed two things - first that boost around 3k rpm didnt come on smooth, you sort of felt it waiver a bit. Second, the boost guage showed a max of 6psi in 1st and second. I recalled from my first drive with the WGDS removed that it was alot smoother, and I got 6.5-7psi on my guage. But I had the pesky CEL when I did that. To bypass the valve I simply left the wiring harness for it connected and the valve in place. Then I simply capped the line coming from the intake plenum, and directly connected to the turbo outlet to the wastgate actuator. Now I get smooth boost, 6.5-7 psi in all gears, and no wavering. Plus no CEL. All in all another RX is back from the dead. Next up is getting the seats recovered and a few other odds and ends, but I'm totally pumped to have this thing running good. Edited December 30, 2020 by Scoby4wd 1 Quote Link to comment Share on other sites More sharing options...
Step-a-toe Posted December 31, 2020 Share Posted December 31, 2020 Thanks for coming back in with the YouTube and detailed, easy to understand post ! I have both this, the Series 2 in my Vortex and Series One in my Brumby. Series One did not get the WGDS thank Fuji. I did find though, to add a very basic boost controller with spring, ball and tiny bleed off hole gave crisper control of boost on , seems to over ride the old factory components whether I use 8 or 12 psi . 12 has been hard on the exhaust gaskets between head and turbo manifold : sad face : Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 2, 2021 Share Posted January 2, 2021 Having a boost control solenoid with a tiny baby turbo is often useful as you can run the boost a little higher than WG and you can pull the wastegate closed at high RPM when the engine is pulling the boost of the turbo down. Of course you need a programable solenoid to do this and the appropriate boost pressure transducer, etc/ But yeah you can increase the boost and hold it longer - most Subaru ECU's will handle a few psi above wastegate. 10psi total would likely be fine. GD Quote Link to comment Share on other sites More sharing options...
Scoby4wd Posted January 4, 2021 Author Share Posted January 4, 2021 On 1/2/2021 at 9:58 AM, GeneralDisorder said: Having a boost control solenoid with a tiny baby turbo is often useful as you can run the boost a little higher than WG and you can pull the wastegate closed at high RPM when the engine is pulling the boost of the turbo down. Of course you need a programable solenoid to do this and the appropriate boost pressure transducer, etc/ But yeah you can increase the boost and hold it longer - most Subaru ECU's will handle a few psi above wastegate. 10psi total would likely be fine. GD Thanks for the info. I am very happy with how it run's and drives right now so I think I am just going to leave it alone. I'm not looking to race this thing, just cruise it around, so leaving it stock is probably best reliability wise. Quote Link to comment Share on other sites More sharing options...
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