GAflatty Posted March 11, 2009 Report Share Posted March 11, 2009 So I finally got my car all back together and I'm just dieing to drive it (since it has been 2 years) and now the thing won't start!!!! long story short I check all three thing that the engine needs to run, fuel/air/spark, and it only tries to start when I spray so starting fluid in the throttlebody below the injectors. I think that my injectors are not getting a signal from the ECU to open. I have power at the injectors but there is no ground (someone correct me if I am wrong, but I believe that power is constant to the injectors and they are controlled by the ECU pulsing the ground to them) So I believe I have a bad ECU but would like to be sure. I was wondering if anyone has a known good ECU that I could barrow. just so I could plug it in and see is she will live. I don't know what ECUs are compatible but I assume I will need one for a non-intercooled car (ya know the ones that both injectors are the same size). The part number on mine is MD071084 I called the local Mitsu dealer today just to see, and of course the are no longer available! but I did get the company name and number that they use to send them to when they needed one rebuilt. If it comes down to needing mine rebuilt. Thanks in advance for any info you guys can provide me with. Link to comment Share on other sites More sharing options...
Tim_C. Posted March 11, 2009 Report Share Posted March 11, 2009 Please share the company who rebuilds our ECU's? I think the injectors are plugged shut. After sitting a while the pintle gets stuck in the orifice and the fuel that turned to varnish. Get them unstuck and it should start. You pretty much have to remove them. I recommend getting them professionally cleaned. That way they can tel you if they were stuck beyond the coils power to get them unstuck on their own. That's what happens, they can't get unstuck on their own. Link to comment Share on other sites More sharing options...
89Steve Posted March 11, 2009 Report Share Posted March 11, 2009 Do you smell a heavy fuel odor when cranking it? You could have your dist. set wrong. Put the engine at 10deg BTDC and verify your rotor it pointing to the #1 plug post (youll have to take off cap). While your at it be sure all wires are to correct plugs. Link to comment Share on other sites More sharing options...
GAflatty Posted March 11, 2009 Author Report Share Posted March 11, 2009 (edited) the car shouldn't be out of time. i parked it where it sits under its own power just a couple of months ago. Also i did take the injectors (which are fairly new) out and tested them to make sure that they weren't stuck shut (they were good), but still no start. thanks for the thoughts guys, it helps make sure i checked everything. the company info is in my toolbox at work i will bring it home tonight and share with SQC. Edited March 11, 2009 by GAflatty Link to comment Share on other sites More sharing options...
83_project_toy Posted March 11, 2009 Report Share Posted March 11, 2009 not sure if this will help and i dont understand why it helped with the this 88 i have here but it did. i put new trilogy injectors and some new clips on and primed the fuel pump off the test port. but the car would just crank and crank not even try to fire. looked at the injectors they weren't firing. poured some gas in the tb and started the car that way but after a few seconds the car started running on it's own and will fire up every time that way now. Link to comment Share on other sites More sharing options...
FlattopMike Posted March 11, 2009 Report Share Posted March 11, 2009 Try pulling the fuel return line off and point it into a can to see if you are pumping fuel up to the injectors. Link to comment Share on other sites More sharing options...
Technology Posted March 11, 2009 Report Share Posted March 11, 2009 Yeah, make sure there's gas in the tank. Link to comment Share on other sites More sharing options...
Tim_C. Posted March 11, 2009 Report Share Posted March 11, 2009 If the pump isn't coming on, it could be the control relay or a bad pump of course. It is rare to have an ECU go bad in one of these. Link to comment Share on other sites More sharing options...
GAflatty Posted March 12, 2009 Author Report Share Posted March 12, 2009 Try pulling the fuel return line off and point it into a can to see if you are pumping fuel up to the injectors. i did that, i have plenty of fuel being delivered (and building pressure) to the top of the injectors. Yeah, make sure there's gas in the tank. yeah i did that too. Just to make sure my fuel guage wasn't lieing to me i put 5 more gallon in it. :thumbsup: If the pump isn't coming on, it could be the control relay or a bad pump of course. It is rare to have an ECU go bad in one of these. the pump is coming on, and flowing very well. it is good to know that ECU issues are rare! Link to comment Share on other sites More sharing options...
GAflatty Posted March 12, 2009 Author Report Share Posted March 12, 2009 (edited) Here is the company info that the parts guy at the dealership gave me: Beckmann Technologies 1-800-742-1021 and I found that they do have a website! http://www.beckmanntechnologies.com/services.html They advertise that they do Mercedes-Benz stuff, but i guess they can do just about any companies electrical stuff... maybe Edited March 12, 2009 by GAflatty Link to comment Share on other sites More sharing options...
89Steve Posted March 12, 2009 Report Share Posted March 12, 2009 You'd be better off just buying a used ECU off here for $30 instead of rebulding it...i see that being expensive anyway so you've established you have good fuel flow/pressure. and your injectors are firing. did you put a stethoscope up to the TB then have a someone try and crank it. Clicking it what you want to hear. If all that checks out you should move on from fuel... timing you said is ok cause neither the distributor nor engine has been touched? back track.. what did you take apart? are all electrical connections where they should be. Do you have your injector clips reversed? Spark...is the coil giving good spark when you hold the high tension wire to ground? How about each plug? Are any of them fouled? Is your MAS hooked up? Link to comment Share on other sites More sharing options...
shift1313 Posted March 14, 2009 Report Share Posted March 14, 2009 you also have the ballast resistor pack inline up behind the pass headlight/airbox. You are correct that the ecu switches ground. Your car is an ES right? the autos and manuals had different ecus. I think i have an 84/85 manual ecu and an auto ecu. Im with tim, its rare for it to go bad. here are the two spares I have but I couldnt tell you if they work or not but i thought they were both 84/85s http://filebox.vt.edu/users/maperez/Starion%20Parts/ECU.JPG before i got my car in 02 i know the previous owner purchased lots of parts to try and figure out the no spark issue(guess they didnt realize the ecu didnt control spark). Do you have an oscope? or an analog multi meter. I dont know if you will be able to see the ground switching without a scope on the injectors but its possible with an analog one(maybe). How did you test the injectors? If you pull the top mixer body off(leaving the fuel line attached) does fuel spray out there? or did you pull the fuel line off to test? Whats the voltage on your tps? Have you tried unplugging the mas and cranking it? If you look up the ecu numbers and think either of those I have will work let me know. Id like to keep them but i dont mind sending them down there for you to test with. Link to comment Share on other sites More sharing options...
GAflatty Posted March 17, 2009 Author Report Share Posted March 17, 2009 (edited) Thanks for the input guys! it will be a few days before i can get back over to my buddy's shop (where the car is located) and tinker alittle more. i don't have an oscope but i might have access to one. i will have to check. then i can check the wave patterens. here is what has happened so far. 1) i have spark at the plugs, and they show no fouling signs. 2) when i spray starting fluid below the injectors it will start until it is all burned. then dies (of course) a) i removed the fuel line feeding the injectors, held it over a cup and turned the car over. plenty of fuel and pressure flowed into the cup. b ) took the injectors out plugged a test harness into the injectors and use a power tool battery (less then 12v) to see if they were "clicking". one was stuck but i was able to free it with this test. however still no start. 3) connect a noid light to injector harness and no flash when cranking. a) check and confirm power at injectors with test light b ) check for ground at injectors while cranking, none found. 1) checked for ground signal to injectors from ECU with test light and non found. this is of course assuming that i was able to get a good connection ( i believe i did) with the test light to the pin out of the ECU. i do have a spare ballast resistor pack that i did plug in and no change was noted. i have not tried unplugging the MAS yet i will do that first thing the next time i am there. Shift thanks for the info and help!! i quess my car is an ES i really don't remember what all the differences are. :sweatingitout: it is a manual car. i will try to unplug the MAS next time out and if still nothing i might take ya up on using your ECU to test and send it back to ya. :thumbsup: thanks again. Edited March 17, 2009 by GAflatty Link to comment Share on other sites More sharing options...
Tim_C. Posted March 17, 2009 Report Share Posted March 17, 2009 It could be the ECU, or a break in the wiring harness somewhere. My '83 had a similar problem that I traced to a harness connector in the center console no less! I am not sure if the '84/'85's have that same harness routing. Link to comment Share on other sites More sharing options...
shift1313 Posted March 17, 2009 Report Share Posted March 17, 2009 the ES part wouldnt matter for the ecu, but all ES cars were 5 speeds(which is where the ecus differ). if i remember the pic from your old sig right your car is black with tan interior and had the same rims mine does(15x6.5) es only. Oh an all ES models had the velnas computer below the radio. I know if you have a problem with your harness i think there were 6 different engine harnesses that year(84/85) so hopefully you can track down the wires if thats it. When you were testing the injectors did you squirt anything through them or just listen for them? Here is a pic of the inside of the ecu http://filebox.vt.edu/users/maperez/Starion/85ECULabel.JPG I was able to get specs(or something close for the caps) but never found any info on the bjt(not fets that was my mis-label) used. BUT these are the two main components that would go bad in the injector circuit. Ive traced the board a few times trying to track it down but its very difficult. I was actually getting ready to try to pull the hex dump off the chip about 6 months back when i just pushed the project aside. The BJT(bipolar junction transistor) is the switch and the cap smooths out the signal. These are the components that will ultimately switch the ground off/on. Id say it would be pretty odd for both circuits to fail since they are isolated from each other except for at the chip and the chance of the chip going is slim unless the power control stuff on the board went up. There were a few posts(dont remember which forum, engine mods i think) that i posted info/numbers off the chips and i think a link to a "close" cap. It may be worth cracking your ecu open just to see if you have any noticeable issues. Link to comment Share on other sites More sharing options...
FlattopMike Posted March 18, 2009 Report Share Posted March 18, 2009 Does your tach jump around when cranking? The ECU needs to see a tach signal before it will fire the injectors. Link to comment Share on other sites More sharing options...
shift1313 Posted March 19, 2009 Report Share Posted March 19, 2009 thats a good point mike. i know the tach signal wire is shielded going to the ecu. does the tach(dash) come from the ecu, i cant remember. Link to comment Share on other sites More sharing options...
Tim_C. Posted March 22, 2009 Report Share Posted March 22, 2009 I have had 2 '83 cars that run fine without the dash tach working, so I'm pretty sure the signals are separate. Link to comment Share on other sites More sharing options...
GAflatty Posted March 27, 2009 Author Report Share Posted March 27, 2009 You know i hadn't notice i will need to check that. i did unplug the MAF and there was no change in the starting issue. i will plug the ecu back in and check the tac the next chance i get to go to the car (which will be sunday at the soonest ). thanks again for all the input guys ya'll have help me think of things that i had forgoten to check!! Link to comment Share on other sites More sharing options...
FlattopMike Posted March 30, 2009 Report Share Posted March 30, 2009 I have had 2 '83 cars that run fine without the dash tach working, so I'm pretty sure the signals are separate. When I installed my MSD ignition, I 1st tried to start it without the tach adaptor installed. It wouldn't start. I installed the tach adaptor and it started right up so the ECU and the tach start out from the same source. I also have the digital dash so maybe that makes a difference. Link to comment Share on other sites More sharing options...
Tim_C. Posted April 2, 2009 Report Share Posted April 2, 2009 When I installed my MSD ignition, I 1st tried to start it without the tach adaptor installed. It wouldn't start. I installed the tach adaptor and it started right up so the ECU and the tach start out from the same source. I also have the digital dash so maybe that makes a difference. I'm talking about the gauge in the dash which was what he was asking about. The ECU must get it's signal. Your first attempt at the MSD was not supplying the signal to ECU so it wouldn't start. That doesn't mean the tach gets its signal from the same source. If it did, then my car wouldn't run because the tach does not work. Unless there is a harness problem between there and my tach. You could be right, but I was thinking they were separate. Mike_C. would know off the top of his head. I would need to look at the schematic. Link to comment Share on other sites More sharing options...
GAflatty Posted April 17, 2009 Author Report Share Posted April 17, 2009 Still no progress yet. :mad: i really wish i had more time to work on this. at this rate i might not make it to PF!!! at any rate rant aside, i was thinking is there a crank position senser? wouldn't it get the crank postion from the distributor? or am i overlooking something? Shift, i have have to take you up on letting me barrow an Ecu for testing just so i can stop thinking about if mine is bad or not. thanks again guys hopefully i will get it figured out sooner rather than later. Link to comment Share on other sites More sharing options...
shift1313 Posted April 18, 2009 Report Share Posted April 18, 2009 no crank position sensor for the ecu. The injectors arent "timed" to any valve or cycle. Ignition is totally separate from the ecu. There is a "pickup" in the dist. that goes to the knock box if i remember correctly. If you end up wanting/needing that ecu just shoot me a PM. Ive been checking the board about once a week so i may not get back to you right away. Link to comment Share on other sites More sharing options...
shift1313 Posted April 18, 2009 Report Share Posted April 18, 2009 also did you ever notice if your tach was jumping during cranking? Pull the connector off the knock box(ic ignitor) on the drivers side fender near the coil. the pins in the connector get corroded and the pins get bent and make bad contact. the black wire going to this connector is the ground. test this wire to see if you have a good chassis ground. If not run a test lead from that wire to the intake ground point or somewhere on the body and give it a go and see what happens. Link to comment Share on other sites More sharing options...
GAflatty Posted May 21, 2009 Author Report Share Posted May 21, 2009 Okay so it has been over a month and i finally had a chance (between work and all the rain) to go tinker with the car for like thirty mins. I reconnected the ECU and tried to start it. Mainly to remind myself what all the car was or was not doing. It still did not start, of course (though part of me was wishing). If i remember correctly the tach did not jump while cranking. I do have one question however (it has been so long since the car ran i don't remember if this is normal or not) circled in the photo below are to vaccum valves (shift is this what you are talking about?) one of them goes click click click click continuously when the key is in the on position. it is kind of hard to tell for sure but i belive it is the bottom one. Any insite on this? once again guys thank you so much for your help and hopefully i will have some time to devote to this thing soon to gett it back on the road!! http://i74.photobucket.com/albums/i245/bkbenson83/1984%20Plymouth%20Conquest/conquestinnerfender1-1.jpg Link to comment Share on other sites More sharing options...
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