86subieXT Posted January 30, 2012 Share Posted January 30, 2012 Need a hand with an old EA82t that's past 100,000kms and starting to run into trouble. I had an idea to replace the older fappy paddle MAF for some newer MAP style technology. The subarus maf puts in 7 volts and reads the remaining resistance to calculate fuel tables. I may be wrong? Map work the same put off manifold pressure and less voltage. It would be nice to have the voltage from the MAF work with the 3v necessary for the MAP. The the 3v MAP sensor fry with 7v? or is there may be a 7v MAP sensor. i doubt it. What do you think is another alternative? Quote Link to comment Share on other sites More sharing options...
zukiru Posted January 30, 2012 Share Posted January 30, 2012 Why not just get a good factory flapper and be done? But you could look at factory Toyota flappers.. very similar and much more common. Quote Link to comment Share on other sites More sharing options...
naru Posted January 30, 2012 Share Posted January 30, 2012 Waste of time. Stock is readily availible if yours is fubared. Quote Link to comment Share on other sites More sharing options...
86subieXT Posted January 30, 2012 Author Share Posted January 30, 2012 No one thinks there are any advantages to MAP? Quote Link to comment Share on other sites More sharing options...
Turbone Posted January 30, 2012 Share Posted January 30, 2012 Not with the EA82T. Quote Link to comment Share on other sites More sharing options...
zukiru Posted January 30, 2012 Share Posted January 30, 2012 (edited) Not with the EA82T. There could be with megasquirt or a Hondata ecu or something tunable. But to try and get the stock ecu to read a map seems like a lot of work for little (no) return. Edited January 30, 2012 by zukiru Quote Link to comment Share on other sites More sharing options...
86subieXT Posted January 30, 2012 Author Share Posted January 30, 2012 Yea i know. i could do it on a standalone but the whole purpose of the idea was to do it with a factory MPFI Well while i have your attention. does anyone know what causes loss of acceleration and hesitation? thermo switch was replaced, no codes at idle. Quote Link to comment Share on other sites More sharing options...
Turbone Posted January 30, 2012 Share Posted January 30, 2012 Clogged cat maybe. Quote Link to comment Share on other sites More sharing options...
zukiru Posted January 30, 2012 Share Posted January 30, 2012 Fuel system or ignition troubles also. Quote Link to comment Share on other sites More sharing options...
naru Posted January 30, 2012 Share Posted January 30, 2012 Yea i know. i could do it on a standalone but the whole purpose of the idea was to do it with a factory MPFI Well while i have your attention. does anyone know what causes loss of acceleration and hesitation? thermo switch was replaced, no codes at idle. Lotsa possibilities. Start w/ignition.Plugs,wires,cap,rotor. Shiity gas/bad timing activating the knock sensor and pulling timing back perhaps. I would check fuel pressure too. Up pipe leak.Not sure about hesitation w/this. Quote Link to comment Share on other sites More sharing options...
MilesFox Posted January 30, 2012 Share Posted January 30, 2012 (edited) You could possibly go to a MAF hotwire setup and then upgrade to some sort of nissan part along with injectors if you are attempting to tune an xt. The simplist way would be to do a complete harness swap from an 87 or later, but this would be the most work. I just got into an xt with a flapper maf, and this one is totally frankenbuilt with spider intake, intercooler, header, cams, xt6 interior, and with that it has incompatibility issues with the pinouts on the TPS (4 pins vs. 3, spider intake instead of original regular intake) and the one on there is installed backwards with a hole through the cover and long screws. Overall, under the hood is mixed up between 86, 87, and 88, which are all schematically different from their original applications. This car does not run right and i'm afraid it would blow up if it's driven wrong. I got it this way, and it will be my spring project when i am ready to dive into it, ant try to use more modern oem subaru parts that didnt exist in the USA when this car was built Nissan and Subaru are cousins in common manufacture, so look into that as an option from cars from the same era if you are making a serious attempt with tuning an ea82. Some folks here will hate on the ea82T, but this is coming from the folks who have taken the ea82T to its utmost potential, and blew them up. But only if you are going for max tune. If you tune it properly it will be reliable. In fact the system can run on 8.0 compression all day by design, but it was designed with 7.7:1 compression to ensure reliability for the consumer car buyer. It is a finicky engine, but it will be good if you know it well. I do like your idea, and if you are proficient with schamatics and autos, all you need is the specifications to figure it out. good luck Edited January 30, 2012 by MilesFox Quote Link to comment Share on other sites More sharing options...
86subieXT Posted January 30, 2012 Author Share Posted January 30, 2012 Those are all common things that ive checked or wouldnt apply since the problem is intermittent. Happens often at operating temps. runs better cold. Also worse with more load on the engine. Quote Link to comment Share on other sites More sharing options...
86subieXT Posted January 30, 2012 Author Share Posted January 30, 2012 I was thinking what portion of the fuel injection system would cause that. MAF or TPS. Quote Link to comment Share on other sites More sharing options...
MilesFox Posted January 30, 2012 Share Posted January 30, 2012 Those are all common things that ive checked or wouldnt apply since the problem is intermittent. Happens often at operating temps. runs better cold.Also worse with more load on the engine. Look into the coolant temp sensor on the back of the intake near the turbo. Check for corrosion on the terminals. Quote Link to comment Share on other sites More sharing options...
86subieXT Posted January 30, 2012 Author Share Posted January 30, 2012 You could possibly go to a MAF hotwire setup and then upgrade to some sort of nissan part along with injectors if you are attempting to tune an xt. The simplist way would be to do a complete harness swap from an 87 or later, but this would be the most work. I just got into an xt with a flapper maf, and this one is totally frankenbuilt with spider intake, intercooler, header, cams, xt6 interior, and with that it has incompatibility issues with the pinouts on the TPS (4 pins vs. 3, spider intake instead of original regular intake) and the one on there is installed backwards with a hole through the cover and long screws. Overall, under the hood is mixed up between 86, 87, and 88, which are all schematically different from their original applications. This car does not run right and i'm afraid it would blow up if it's driven wrong. I got it this way, and it will be my spring project when i am ready to dive into it, ant try to use more modern oem subaru parts that didnt exist in the USA when this car was built Nissan and Subaru are cousins in common manufacture, so look into that as an option from cars from the same era if you are making a serious attempt with tuning an ea82. Some folks here will hate on the ea82T, but this is coming from the folks who have taken the ea82T to its utmost potential, and blew them up. But only if you are going for max tune. If you tune it properly it will be reliable. In fact the system can run on 8.0 compression all day by design, but it was designed with 7.7:1 compression to ensure reliability for the consumer car buyer. It is a finicky engine, but it will be good if you know it well. I do like your idea, and if you are proficient with schamatics and autos, all you need is the specifications to figure it out. good luck Wow, sounds like you have a project on your hands. I personally am fighting to keep my ea82t engine running good. My intention is to tune it properly. Methanol injection forge boost controller and bps TMIC have been added. What do you recommend. [/img] Quote Link to comment Share on other sites More sharing options...
MilesFox Posted January 30, 2012 Share Posted January 30, 2012 (edited) The one i have is oldschool: Ford thunderbird intercooler and volvo recirc valve. I would like to ditch this stuff and go with oem WRX but that will physically fit more properly. Depending on the overall volume of air and fuel, i would thinnk the maps on the ecu would maintain duty cycles and dwell time with larger MAF and injectors producing a larger proportion of fuel and reading a larger proportion of air. My one buddy in georgia is setting up his svx with nissan 300z MAF and injectors. The xt i am working with has a set of nissan 240 injecotrs that came with it to be installed. I would like to retrofit to hotwaire maf myself. I know that a nissan 240 coolant temp sensor is compatible (green top vs subaru brown top) as i found this out trying to get one for my 87 rx where it was not in stock, but the same part number came up for the nissan , which was in stock. Perhaps the nissan would have a different temperature rance that can manipulate the ecu for a different stoichiometric ratio. I h ave been working on translating my 88 xt fsm manuals to html so people can browse and search it. I would need to compare the 87 and 86 fsms to see what parts of it are redudatn and what parts are specific, as the schematics should be grouped by 85-86, 87 (think of an 88 with 86 shaped plug-ins, and 88 up. Based on comparing the schematics to eachother, i would know what i am up against. Keep the boost withing 7 psi as that is the one thing that will kill your engine is overboosting. You probably know this. The xt i have has 8:5 compression using a block from an 87 carb gl. the disty is not correct as it should have a connector for the external knock control unit. the 1987 and up did away with the EKU and integrated it with the ecu using an optical dist instead of a mechanical. Edited January 30, 2012 by MilesFox Quote Link to comment Share on other sites More sharing options...
86subieXT Posted January 30, 2012 Author Share Posted January 30, 2012 good info there for tuning. Now what can you tell me about hesitation under load? some sensor or operation is cutting out when the car is under load at operating temp. Quote Link to comment Share on other sites More sharing options...
Turbone Posted January 30, 2012 Share Posted January 30, 2012 Wow, sounds like you have a project on your hands. I personally am fighting to keep my ea82t engine running good. My intention is to tune it properly. Methanol injection forge boost controller and bps TMIC have been added. What do you recommend. Swapping in a EJ (read my thread in the retrofit forum) Quote Link to comment Share on other sites More sharing options...
naru Posted January 30, 2012 Share Posted January 30, 2012 Those are all common things that ive checked or wouldnt apply since the problem is intermittent. Happens often at operating temps. runs better cold.Also worse with more load on the engine. Sure sounds like shiity gas activating the knock sensor and pulling timing back. Put a voltmeter on the phase correction signal wire to the disty.Monitor the voltage while driving to confirm. Similarily,hook the voltmeter to the O2 sensor to see if the mixture goes lean when warm. Quote Link to comment Share on other sites More sharing options...
86subieXT Posted January 30, 2012 Author Share Posted January 30, 2012 Sure sounds like shiity gas activating the knock sensor and pulling timing back.Put a voltmeter on the phase correction signal wire to the disty.Monitor the voltage while driving to confirm. Similarily,hook the voltmeter to the O2 sensor to see if the mixture goes lean when warm. this problem happens every tank. Quote Link to comment Share on other sites More sharing options...
MilesFox Posted January 30, 2012 Share Posted January 30, 2012 the TPS becomes finicky withthese. There is an idle circuit, a WOT circuit, and a variable in the middle. The TPS is adjustable if you have a meter and the procedure specs (factory manual) You can remove the TPS and manage to pop the cover off and clean the contacts inside. Sometimes they get a green corrosion on the contacts, and this changes the values the ecu is seeng. Hesitation part-throtte and under toad is TYPICAL of the ea82t. i recommend you try to rebuild,clean and dielectric grease the TPS and see if that improves. The sad thing is, if you try to find new replacement parts like a tps or similar, they end up being hundereds of dollars as they would be the handful of remaining new-old-stock that would have to pass through several vendors to get to you. I recommend the junkyard for replacement parts, and just have a few on hand. Quote Link to comment Share on other sites More sharing options...
86subieXT Posted January 30, 2012 Author Share Posted January 30, 2012 the TPS becomes finicky withthese. There is an idle circuit, a WOT circuit, and a variable in the middle. The TPS is adjustable if you have a meter and the procedure specs (factory manual) You can remove the TPS and manage to pop the cover off and clean the contacts inside. Sometimes they get a green corrosion on the contacts, and this changes the values the ecu is seeng. Hesitation part-throtte and under toad is TYPICAL of the ea82t. i recommend you try to rebuild,clean and dielectric grease the TPS and see if that improves. The sad thing is, if you try to find new replacement parts like a tps or similar, they end up being hundereds of dollars as they would be the handful of remaining new-old-stock that would have to pass through several vendors to get to you. I recommend the junkyard for replacement parts, and just have a few on hand. TPS is a likely candidate for this problem. I will test that competent tonight. Also plan on sweeping through the MAF and confirming proper readings to the FSM. Thanks for your input. very good forum here. Quote Link to comment Share on other sites More sharing options...
MilesFox Posted January 30, 2012 Share Posted January 30, 2012 If your MAF is whack, i have a spare that came with my car. If you think you might need it, make me an offer. If you are looking on the http://www.subaruxt.com forums, look up 'monsterwedge' to see my car as it was posted by the previous owners. Quote Link to comment Share on other sites More sharing options...
86subieXT Posted January 30, 2012 Author Share Posted January 30, 2012 just pulled apart the TPS to clean and meter it. ive never seen a TPS like this before Here it is no throttle Here it is WOT And here is is everywhere in between How is this TPS only operating through continuity? Quote Link to comment Share on other sites More sharing options...
naru Posted January 30, 2012 Share Posted January 30, 2012 It only senses 3 positions. Idle, "full" throttle,and in between. Check contact resistance.I had to clean mine. W/reinstalling adjust position.IIRC,full throttle switch closes at 45 degree throttle opening. Quote Link to comment Share on other sites More sharing options...
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