Ray-Ray Posted May 16, 2012 Report Share Posted May 16, 2012 ok, first off THANK YOU!!! this site is littered with info on everything you could think of for your StarQuest. (must be why people have a hard time searching on this site lol). so here goes it details: Ok i picked up an 86 TSI for 500 cash, guy said it needed TLC, a windshield, and new injectors. engine did turn over, it is black with a tan hood and headlights. took it home and did a thorough check over, WOW. lots of wires by the injection mixer were spliced together by twisting them, i thought what a nightmare so i open the back hatch and see there is an extra ECU, turbo w/manifold attached, taillight, and "fuselink/relay tree" (hidden behind the battery). hmmmm so i look back under the hood and REALLY look. this car has been wrecked, this is definitely a different engine, explains the extra parts and why part of the car is tan. so i check out where the ECU is located (kickpanel) and right when i get the cover off and put my head down there i see one black ground wire dangling by itself, and another mounted to the PLASTIC blower motor. I thought "how the hell is that gonna work?" i route them appropriately to metal against metal location and the turn the key. fires right up and idles lovely. very noisy though, definitley timing chain slack. order new timing chain kit and install, noise reduces substantially but now there is noise from the top end, Intake side. and it seems like it doesnt run right. took it down the road and it completely falls on its face at WOT but if you just put around it does alright. smokes white around exhaust manifold and compression is 60 across all 4. needs head gasket so i park it and then i found this website and it saved my StarQuest. after an immense amount of searching i found out the engine in my car is from an 87. so is the extra ECU and turbo. The ISC setup is also from the 87 but the turbo on the car is from the 86 because of the intercooler. my car has mechanical rocker setup which HAD to have come from the 86(whole head). explains compression numbers. i find a post for ECU conversion and how to wire ISC to 86 wiring. ok my question.....i ordered new head and gasket kit, and 1G DSM MAS which comes in two days. i have the car completely apart and made appropriate wiring to the isc/mps. sooooooooo..... if any knowledgible questers read this.................. if i make appropiate adjustments to ecu wiring harness to plug into the 87 ECU and wire the MAS correctly, will it work? are there more adjustments to make? Thank you all in advance. oh and what will happen if the balance shaft is not set correctly when replacing timing components? Quote Link to comment Share on other sites More sharing options...
BOHO Posted May 16, 2012 Report Share Posted May 16, 2012 The injecotrs/ecu/ignitor/mas they are all different from 86 to 87. Its a lot of work to do it right...Are you sure that your car has an 87 computer? Quote Link to comment Share on other sites More sharing options...
vbrad511 Posted May 16, 2012 Report Share Posted May 16, 2012 87 used a different injection system than 86. There is no realistic way to plug an 87 ecu into your car without changing the harness. What are the numbers on the ecu? What color are your injectors? Sounds like you've got some bugs, but keep feeding us details, you'll get there. Quote Link to comment Share on other sites More sharing options...
Ray-Ray Posted May 16, 2012 Author Report Share Posted May 16, 2012 yes i have the green secondary injector "M" stamped on side and black primary with "L" i have the 86 computer hooked up and the car runs because of the simultaneous injection on the 86 ecu. i also have the 87 ecu that was in the trunk area when i bought the car i know this because it is model number MD106 i have the entire setup from an 87 except the MAS. I understand that i can relocate the wires that plug into the ECU to make it read the right signals to make the injectors/ignitor/mas work correctly. thank you for your input all is appreciated as it is extremely helpful to double and triple check this type of situation Quote Link to comment Share on other sites More sharing options...
vbrad511 Posted May 16, 2012 Report Share Posted May 16, 2012 The 86 ecu is a batch-fire system, meaning both injector fire at the same time. 87-89 run on the primary until the secondary kicks in as more throttle is applied. There are more numbers on the ecu's. If you post them up we can verify their years. Been a long time since I've been under an 86, and I never had to do much to either of the ones I had. Hopefully somebody who's tinkered a bit more with theirs will chime in. Quote Link to comment Share on other sites More sharing options...
Ray-Ray Posted May 16, 2012 Author Report Share Posted May 16, 2012 86 ecu # MD101177 other ecu (87) #MD106394 Quote Link to comment Share on other sites More sharing options...
Ray-Ray Posted May 17, 2012 Author Report Share Posted May 17, 2012 note: I would just keep the 86 ecu hooked up but then i would have to get the correct injectors or more likely the whole throttle body/injection mixer. i have everything i need to make the 87 ecu work (theoretically) i was just wondering if anyone on here has done something like this and could tell me if they were successful or not...... Quote Link to comment Share on other sites More sharing options...
Spooled_Starion Posted May 17, 2012 Report Share Posted May 17, 2012 From my understanding an 86 is like the red headed step child. A 1G DSM MAS won't work with an 86 harness (86 mas is a 4 pin connector while a dsm maf is a 7 pin connector.) people like the 86 because it's lighter than the rest. 60psi per cylinder is really low and could quite possibly require new valves/rings. If I am wrong someone should correct me but thats just my understanding. Quote Link to comment Share on other sites More sharing options...
strang3majik Posted May 17, 2012 Report Share Posted May 17, 2012 If you have a black and green injector, that could be part of the issue. As said, 86 is a batch-fire system, so, the fuel mixture is probably all messed up with two different sized injectors. Also, is the MAP sensor on the firewall still there and hooked up? As far as falling flat on its face, is it building boost at all? Is there a certain RPMs its falling off at? Doesn't it fall off and hit it like a brick wall or does it just choke for a second, then take off again? Quote Link to comment Share on other sites More sharing options...
vbrad511 Posted May 18, 2012 Report Share Posted May 18, 2012 You can't just plug an 87 ecu into an 86 car. They're wired differently, different sensors, just won't work. You're better off springing for the right injectors...or changing the entire harness to an 88-89. Quote Link to comment Share on other sites More sharing options...
Ray-Ray Posted May 18, 2012 Author Report Share Posted May 18, 2012 LOL... ok..... i know why my car does not run right when it is hooked up to either ecu. 86 batch-fire makes 850cc injectors run simultaneously, since my are 580 and about 1000-1080cc it has incorrect air-fuel mixture and then when i go WOT the secondary never receives the ignitor signal for injector timing, they just run simultaneously so it falls on its face. hook up 87 ecu and it idles lovely, but when you get on it, it hits about 3k and feels like you hit a brick wall. this is because the ignitor signal is not getting to the ignitor. the 86 wiring makes the ISC retraction wire plug in where the ignitor signal is supposed to go, among other incorrect signal locations. if you take a tiny screwdriver and push in the correct direction on any of the female pins and pull on the wire they come out of the harness. ANY of them. so just because 86 stock MAF has 4 pins and a 1g has 7 (6 that we use) doesnt mean i cant hook it up, it just means i cant use the round 4 pin stock harness, so i take the wires out of the round harness and could literally just slide the female connector onto the male pins on the 1g MAF (obviously wont do because of protection factor) and route the correct wire for the barometric pressure sensor and the intake temp sensor to the correct pin location on the 87 ECU. on the ecu harness (plug that all the wires come out of) i can take out the female pin connectors and relocate them to the correct 87 ecu pinout, the only thing on my car that is 86 is the body and all of the wiring. all the ECU's have the same number of pins, its just that the pins read different signals. i know what injectors i have, i know i have 87 isc setup, i know why the injectors are doing what they are doing, i know what sensors the 87 has that the 86 doesn't, i know MAF only has 4 wires instead of 6. so why couldnt i add the two wires i need? one for 12v and another to ecu for barometric pressure sensor. i know the cars are wired differently and know that the later models use a few more wires for the other sensors the 86 doesnt have and that some wires are different colors, (they could all be black and it wouldn't make a difference, as long as each wire was routed to the correct sensor and then back to the correct pin on the ecu) i know what adjustments i need to make to the wiring to have it receive/send signals correctly. With all of that aside..... has anyone ever done this before? theoretically it should work but i dont doubt for a second that it could just as easily fry the whole computer or leave me with other catasrophic disasters. anyone have an experience they could share?? Quote Link to comment Share on other sites More sharing options...
Komeuppance Posted May 18, 2012 Report Share Posted May 18, 2012 There's a guide to convert your harness from 86 to 87 in the FAQs... take a look there. -Robert 1 Quote Link to comment Share on other sites More sharing options...
strang3majik Posted May 18, 2012 Report Share Posted May 18, 2012 I don't think you can just swap ECUs as the I believe the pin-out is different as 86 was an odd year. Your best and easiest bet is to get a later harness and just swap it over. Not entirely difficult and you could get one for cheap, I'm sure. But, 87-89 shared basically the same pinout...as I said, 86 was slightly different. Quote Link to comment Share on other sites More sharing options...
Ray-Ray Posted May 18, 2012 Author Report Share Posted May 18, 2012 Thank you Robert Quote Link to comment Share on other sites More sharing options...
Zone Posted June 1, 2012 Report Share Posted June 1, 2012 (edited) A 1G DSM MAS won't work with an 86 harness (86 mas is a 4 pin connector while a dsm maf is a 7 pin connector. There's a conversion topic pinned about running a 1g maf on a 83.It works as i have tried it with my 85 which is 4 pin. The 2 extra wires could theoretically be connected to the wiring over on the throttle body which connect to the airflow sensor.87-89 starions/conquests don't have a sensor in the pipe, its in the maf, therefor its 6 plugs vs 4Course i could be wrong. Edited June 1, 2012 by Zone Quote Link to comment Share on other sites More sharing options...
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