one coil not giving spark.

[chrisisg77]

I thought i fixed the problem before. Anyways i have brand new coils. Although my first coil doesnt have spark and i have weak spark. i tried switching them around to see if the first one didnt work but it does. Next i decided to look at my CPS. I found out that two pins were switched around so i redid the wiring on it . But still no spark on first coil ! By the way as i went on i made sure everything was properly pinned on harness side to the ECU. So i got to my igniter and i found something strange

one side is completey off ! Thats why i might have weak spark . Not only that but the inside of the bottom case is lifted up and might be touching the c1 signal wire to my 1st coil grounding it out ?

so right now im doing the igniter ground mod and also flattening out the case and maybe put a strip of electrical tape inside the case as extra.

 

[Nick M]

What do you mean you switched wires on the CPS? The PCM is looking for a specific signal, and they are not interchangable. Go ahead and ground it. But that also will not cause one of three coils to not fire. Fire weak, sure.

 

[jonahs_supra]

here ya go
http://www.supramania.com/forums/content.php?208-IGNITER-GROUND...-crispics

 

[jetjock]

It just keeps getting better...

 

[JStoked]

+ 1 to that jj.

 

[chrisisg77]

Nick M you miss understood me. Ok as in the previous owner of the cps TRIED to correctly wire the cps pick ups according to pins on the plugs . I saw that my wires were upside down. So i used TEWD to pin them correctly to each pin on the plug.now they are properly pinned like this. male cps plug 1.NE 2.G1 3.G- 4. G2 and on harness female plug its the opposite of course. See www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=040
As i looked on here some dude had the same problem but when he properly pinned them his started . And im pretty sure i did it right as i tend to check things over 5+ times (little OCD)
And i already did the mod thanks though jonahs.

 

[3p141592654]

G1 & G2 would be the only possible combination that could be flipped. The ECU won't care though, and it surely won't impact the spark intensity.

Measuring your ignition HT voltage on a scope for each plug would be a much better idea than all this futsing around in this thread and your other one.

 

[chrisisg77]

Yea i give up

 

[chrisisg77]

Ok not giving up just yet did a bit of reading! Ok so the G pickups represents #1 and #6 pistons approaching TDC on compression stroke. Correct? First i would start here with the logic probe? As it generates a AC signal using these and NE. Then the ECU would pick up these signals and generate the IGT, IGda and IGdb. Then the ECU tells the igniter which coil to fire using the IGd's and then tells the igniter to turn on that coil using IGt. Then It sends a binary code to igniter to tell it which coil to fire. Correct ? As in IGda is 0 and IGdb is 1 so that would be cylinder No.1 and No.6 , so (0,0) would be cylinder No. 3 and 4, and (1,0) would be 5 and 6? Would this be where i would probe it? So as you guys know my 1st coil pack 1 and 6 is not firing so thats where i probe it to see if its sends that signal (0,1)? Also probe the IGT? after that checks out fine i would check power transistors in igniter using a 3volt battery right? I havea feeling its my igniter. But troubleshoot away! If only i knew how to use a logic probe lol. Time for more reading!

 

[jetjock]

Props for learning how it works and trying to troubleshoot it properly but you shouldn't have to go through all that. If the tach moves when cranking odds are the igniter is good. If you're getting injection the CPS is working. The coil packs can and wiring can be tested separately using the logic probe or a meter. Make sure there's +12 at the packs. They can be test fired by flick grounding them. I'm assuming there's no longer a code 14?

 

[3p141592654]

Yeah, don't give up, use your knowledge to isolate the issue. The problem with your "weak" spark diagnosis is that its subjective, you don't know if it working as designed because you don't have a known good system nearby to compare.

Make a test plan, or use the guide in the TSRM, and go through it methodically. JJ knows lots of tricks from experience, so read his comments above carefully. This is an old car, it can be diagnosed and fixed with mostly common tools and test gear, you just need to have a plan.

 

[jetjock]

Yep, that's good advice. I may have busted his balls a bit but when someone makes an effort to learn and tries to intelligently help themselves I'll be one of the first to get behind them.

 

[chrisisg77]

Thanks guys, i guess all this heartache will be worth it when she finally fires up.

Ok i do have injection i can hear them when i spin the cps. I also have 12 volts on them with the key at the ON position. That rules that out on to the next.

I also have 12 volts to coils with the key at the ON position . Theres no continuity between coils and grounding plate. Your Right i was reading something about that, i was already sleepy and it was late at night But i would do this by attaching a ground wire to terminal 2 to the coil packs plug and tapping a ground spot. This would make the coils "dump" its stored energy causing spark ? This way is easier than using a hex wrench to switch around the coils. But the coils all work.

And for the igniter and tach i dont know if the RPMs needle move because the guy that i was going to buy the GTE cluster never replies to me. So today when i get home from work im just going to pull out my GE cluster from my car and solder in the new resistors and look into that.
Yup no more code 14 turned out that the IGF wire was snipped in half somewhere in the harness
. So todays plan is to build a probe and swap in new resistors on tach and tommorow troubleshoot whats left .

Just out of curiosity lets say if IGda was snipped off and IGdb was still intact. IGdb on its own wouldnt be enough for the igniter to specify which coil to turn on and fire right ? That would mean no spark on any coil? Or would it be able to read (0,0) and (0,1) and causing two coils to fire ?
What would happen if they were spliced in together the IGd's?
Learning about this is fun!

 

[3p141592654]

The IGda/IGdb signals are generated by a chipset in the ECU, and the microprocessor only generates IGt and checks for IGf. So, to answer your question, no there is no code for bad coil select signals, and a bad IGdx signals would result in the wrong coil firing.

But you can check for continuity with a multimeter for all the IG signals from the ECU connector to the ignitor connector.

The "grounding plate" is a shield, so don't worry about its continuity, it won't cause your problem (despite lots of misinformation about what it does circulating around the forums).

 

[chrisisg77]

The IGda/IGdb signals are generated by a chipset in the ECU, and the microprocessor only generates IGt and checks for IGf

Wait i thought the ESA microprocessor generates BOTH IGdx and IGT signals?

Ohh okay well i know that all my IG signals have continuity from ECU to Igniter. However i dont know if they are spliced together which i doubt thats the case.

Really? So the continuity check between coils and shield shouldnt even be on the TSRM?

Ok im off to work on her . Ill check in if i have a problem i cant solve or dont understand of course after reading up first

 

[3p141592654]

If you look at the wiring diagram the coil primaries connect to 12V and the three ignitor "switch" inputs. The secondaries goes to the plugs. There are no direct connections to the shield. The shield is there to minimize EMI interference. I believe the TSRM says to check that there is NO continuity between ground and primary circuits.

If you pull the coil primary harness off the coil pack you can check everything quickly on the bench for broken wires, damaged connectors etc.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=IG&P=12

There is no ESA processor, as one processor does both fuel and ignition. Since Toyota required the car to run with the processor dead, the ignition switching is handled by a couple of dedicated chips inside the ECU.

 

[Nick M]

Wait i thought the ESA microprocessor....

This has it all.

http://www.autoshop101.com/forms/h23.pdf