7mgte no spark
 

so i bought a supra a while ago with the engine out and it had a bhg so i replaced that and the head. So i finally got the motor and tranny in and the wiring that i know of and can see done up. when to go start it i had no power at the coil. traced that back to an unplug ignition wire. went to go crank again and still have no spark. so i went to the toyota service manual and went for the no spark condition and started doing testing and found the ignitor to test bad. Replaced the ignitor and i still have no spark.

I am at a lost of what it could be. Any ideas? I know there are guys out there that know alot more about the supras then i do and could prob give me hints on where to start.

By the way its a 1990 supra with a 7mgte. the cylinder head is off a jdm 7mgte and its not running the egr system and it has arp head studs along with the third verison of toyotas gasket

thanks in advance

anyone have any ideas

No error codes? Manual or automatic transmission? Is there power at the ECU? Does the check engine light up when the key is in the "ON" position but the car is still off? Are the ground wires which connect to the head on the passenger side and the intake manifold on the driver's side all clean and securely fastened?

havent checked for codes yet. ground on the passenger side is good and didnt know there is suppose to be one on the intake... where on the intake does it bolt to and where on the car?

and its manual trans

The other ground I mentioned consists of two eyelets (4 wires, IIRC) and they connect to the bottom of the lower intake plenum (driver's side of the head).

Check for codes, it'll help see if there are any power supply issues at the ECU.

alright thanks man ill check tomorrow

Check to make sure the coil packs are grounded well. when i took mine apart the ground wire was half way decentagrated and the wire was bare. im sure it was causing some of the problems i was experiencing while the car was running but i wont know for sure until i get my new manifold and get her all back together

you took the words out of my mouth there, it's easy to overlook this earth especially if (as with mine) it's broken off the coil carrier. IIRC the coils have their own dedicated earths anyway but Toyota fitted the single wire one for a reason I guess...

where exactly is this ground ground on the coil suppose to be... im pretty sure i dont have on and when i bolt the coil carrier down i never have the rubbers that hold it into place so i just used some washers for now.. is that a big deal?

checked all the grounds.. they are now good but i still have no spark.. im going to check for codes right now

just checked codes.. none at this time anyways.. im at a loss here i have no freaking clue wut it could be.. any other ideas... i timed the cps and even replace it due to the fact that the old wires were very brittle

any one with other ideas on what it could be?

i also just noticed that when the battery is hooked up the check engine light stays light up with the ignition in the off position and key out of ignition. as soon as u turn the key to the run/on position the check engine light will go out. any clues as too why?

that buzzing from the pass side is the fuel pump relay cause my is doing it too

The fuel pump relay is the most likely suspect for the buzzing. The CEL when the ignition is off is puzzling as the ECU has no power source at that point, but I suppose if the fuel pump relay is getting power from somewhere that would be the same source that's powering the ECU. Do either of you have the FP contact in the diagnostic box jumpered to anything?

7mgte no spark & fuel pump rely buzzing
 

Hello,
I have a 88 supra that I've rebuilt the engine in that's showing the same problems. I've confirmed the coils have the necessary 12 volts. earlier posts indicate a ground wire is indicated between the coil pack & the engine ? one of the tests have you checking that NO ground exists ? I'm really climbing the wall, the cars been ready to start for weeks...... I performed the test to confirm the fuel pump works, it does... I also have the engine light on when the key is off ? this is really a "pip", putting it nicely. as the other people have nicely stated "HELP"
Paul

One of you (or all of you) pull the fuel pump relay, jumper FP and +B in the diagnostic box, reconnect the car battery and see if the CEL still comes on with the key at "off". Try starting too if you like, although I doubt that's what's preventing your vehicles from starting.. I think the main EFI relay is more likely.

They are grounds they connect to the lower intake plenum... post the wire colors and I'll double check for you, but I'm quite sure I know what wires you're talking about.

Sure, ECU doesn't get power when it needs it.

glad to hear this problem finally got solved for you ben. its been what? a month?

Crikey o reilly, & I thought a BHG was a swine!!! Glad you got sorted in the end, are you taking any action about the bodged & wasted new starter or have you not had time to think about that sort of stuff yet? I'd be shoving a lawyer down their throats about now...

cre,
I second Benesesso, You nailed it ! ! ! I moved the two wires to a ground stud as described ....... She fired up ASAP................ I had invested an additional 8 1/2 hrs testing per the book before reading your post. I was out there at 8:00p.m. tonight to try it Thanks, thanks, thanks
Thanks again

well its good to know that few other guys are getting their cars running but i have decided that im going through the engine wiring harness wire by wire due to the fact that i know that i have all the grounds hooked up and that i have found some wires that are not in the wiring diagram and i have no idea wut they go to... so instead of guess im going to go through it all so i know wut wire is wut and i that i can remove anything that doesnt need to be in there engine compartment. it may take a while for me to get this down i only have an hour or two a day to work on it. ill keep every one updated on the status of it and when i get it running

so i finally got started on the wiring and holy crap wut the hell did i get myself into hahaha i think i found why no spark... no knock sensor wires or anything

anyother question i got into the ecu and the is the hks fuel cut defender on it. would that cause it to have no spark... i plan on removing it within the next to couple of days but i will be very tight on time due to college and work

FCD is VERY old tech and was a piece of crap and all 'round bad idea even when it was new. Pull it... It shouldn't cause a spark issue (other than causing the spark advance to be a mile off), if it were seriously damaged; It modifies the air flow signal... I don't think it even reads the IGt.

well i am going to remove it tonight... the harness is pretty hacked up so i pulled it out and im going through the whole thing and going to clean it up and tape it up right ill post pics later tonight or this weekend

well i finally got the harness down and back into the car. got everything hooked up. turned out i was missing one ground that was going to the starter and back feeding power to ecu and the knock sensor was missing as well. The car is no running can some wut drivable. needs a few kinks worked out of it. like the fuel tank and limnes need flushed out(two year old gas) need to get the air out of the cooling and power steering systems. need to install my aftermarket IC and piping along witht the intake. then the interior will go back together and it will go get some exhaust... Im thinking just three inch staight pipe, what do you guys suggest?