Supra won't start!!!!!!!!

[Old Man Supra]

Hi, Well I'm just ready to start using my 1986 Supra again.....nice weather here finally. So I have a friend help me as the battery has died during the winter. Ok I leave he gets a new battery and gets it connected...........I come back. He says only the lights come on no power to the igniton no interior lights ONLY the headlights.........see where I'm going with this. Yeah it was connected to the wrong posts on the battery postive to negative, negative to positive....... He said the igniter got warm. I checked all the fuses and so far the 60 in the fuse box under the hood was blown. Put a new one 60 fuse in and got it all connected, the battery is all connected right now as well. I found a radio fuse was blown so I replaced that as well and its now working again. NOW everything works just as before when I parked it for the winter. Everything.......... EXCEPT the motor spins over easy but now the car does not want to start..... so whats happened that I'm missing? no spark I'm guessing. Igniter now bad maybe? or is there something else. I'd like to get this on the road again soon. HELP!

[jdmsoup]

how exactly does it turn over? like does it sound like its sparking or not getting gas into it or what?

[Old Man Supra]

Hello, Well before all this happened it was a turn key ride...........popped right off always. Now it spins over without any effort but hard to tell if its not getting gas or spark. I'm guessing about some things,when the battery got hooked up wrong it could have cooked the coil/igniter...or it could have effected the fuel pump as far as it getting current to turn on and pump...........or anything in the fuse panel under the hood that could have burned out and could be effecting it?,there are relays in that panel and it would be hard to tell if they were good or not still.........not like a fuse where you can see if they are blown. Any help will be appreciated. If I can get this car started I'll be smiling again.

[jdmsoup]

just check all the fuses in the panel under the hood and in the kick panel. because hooking it up backwards probably blew some fuses im guessing. haha so yeah check all of those. my fuel pump fuse blew once in my supra and it would turn over all day but never fire up hhaa and then i checked the fuse. but also take all the carpet out of the back and get to the top of the fuel pump and turn the key and see if you can hear it click on to rule out that problem.

[btwilson86]

Well, you can see if the fuel pump itself is still operational by using a jumper wire in the diagnostic box under the hood. I can't remember for sure, but I believe you check it with the key in the "on" position, then hook up your jumper wire between +B and FP. That should cycle your pump on and you should hear fuel rushing through the fuel rail under the hood. Off the top of my head I can't remember if this bypasses all the relays and such, so if not then you could have a bad relay. Hopefully someone else will chime in and verify that for me.

If you still have fuel, then get an inline spark tester and see if you're getting spark to your cylinders. If you don't, then double check the EFI circuit fuses and relays (I know the 15 AMP under the hood will stop it from sparking). Other than that, I'd consult the TSRM for the testing procedures of the Ignitor.

[Old Man Supra]

Hi Guys, I appreciate those pointers regarding the car. I replaced and looked over all the fuses in the box in the engine bay. The one that was bad was the 60 amp, it was actually brown on the back.........what a son of a gun to get out and.............get back in! But as soon as that one was replaced I had everything fuctioning as it was before.............well OK thats not quite truly obviously but...............that did bring alot of the systems back again. Is the fuel pump fuse in the box in the kick panel? I'm going to pull all the fuses out here in the next couple of days and check them all. The fuse box in the engine bay......... the relays there, do they have any relationship to the fuel or spark issues I'm having? I'll do a very through check on the all fuses first in the next couple of days, I'm not going to run out and buy a igniter when a fuse will do it. I'm confident I can get it sorted out................lesson learned on the battery.............get the terminals connected correctly. I'm still smiling.............its a great car. Gary

[Cameroonski]

Yes he was correct when he said check B+ and Fp on the diagnostic box. Just take a wired and connect the two. If you hear the fuel pump relay make a sound (other side of the engine compartment) and fuel goes through the system, your pump is good.

Things that have to do with that system are the EFI relay (the grey round one on the top right of the junction box i believe) and the EFI fuse (bottom left 15 amp i think). If you still are not getting fuel with all of those things working then get back to me... cuz ive had the hardest EFI system trouble the last few weeks and could tell you almost anything about that system.

Also, pull out a spark plug, plug it into its case... spark plug wire or whatever its call, lol. Then hold it to the engine block while you crank the engine. You should see a spark on the end of the spark plug, if not your problem is in the ignition system.

Hope this helps!

[Old Man Supra]

Hi Guys, Just wanted to follow up with some info that helped me get to the end of the problem and got it fixed. I checked all the fuses...........under the hood and in the drivers kick panel ALOT of them were blown............. replaced all of the bad ones ofcourse. Got a tester and checked for both fuel and spark which even after replacing all the fuses and checking the igniter/coil neither was working. So..................looked at a wiring diagram for the car and the unit that controls both of those functions IS............... The PCM! I went into the dash pulled the glove box out and right up above there it is.Took it out [3 connector bundles and 3 screws]and copied the info off the module. I got lucky and I found a exact replacement right down to the last letter and number...........made sure it was MT for manual tranny and bought it for $125.00 at a local salvage yard...........they kept the brain, the Supra it belonged to was long since crushed. ;( Got home plugged the 3 connectors back in to the New/Used PCM unit then remounted it to the under side of the dash,put the glove box assembly back together and.................turned the key VAROOOOOOOOOOM! Back to life! Runs and operates just as before. : ) Hope this helps someone else down the road.................... but the best thing to do is when your getting mother SUPRA back to go out on the road after a long winter nap make sure you don't have her wires crossed [like on the battery!] I got really lucky that this mistake didn't fry the car or alot of other expensive parts.Lesson learned! I''ll be VERY careful from now on............it a great car that I don't want to lose.

[porsche944god]

ok i hoping it is something as easy as a new ecm.....anyhow 87 na got fuel no spark main relay under from what i can tell has no ground???? if u jump the terminals it will start but runs up to 2000 revs then back to 1100 then back up to 2000 etc etc.....im stumped all i did was pull fuses out and put back in lookin for amp draw wtf??? can somebody lead me another way?