Bad Coils?

[vettedreams2001]

I've got fuel (haven't checked pressure) the plugs are soaked after a few cranks though, I've timed it like haynes and tsrm states (crank at 0', piston at the very top, cam gears lined up to top of intake cover #2, CPS where the drilled portion lines up with the groove and contact points are about touching). I do get spark but it is a very weak orange spark not blue, and the resistance at the connections are .7 ohms (books say .2 ohms - .5 ohms). She still won't start. The only code I am getting is 51, which is AC switch or Neutral safety, but it's a manual, so I'm going with it is the AC for that code. Any thoughts?

 

[10secdream]

The car will not start if the plugs are wet. I would either let the plugs dry off or throw in a new set.

 

[figgie]

the number you gave is out of spec. Are all three coil packs measuring .7 ohms?


is the coil pack grounded properly?

There is a wire that goes to the engine block, i would re-route that wire directly to battery ground (if your battery is upfront still).

What are the spark plugs gapped too?

Verify the igntion wires (HIGH TENSION CORDS) per TSRM

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=IG&P=11

 

[vettedreams2001]

Yeah, all three coils are the same spec, I think they might be original, or at least someone replaced them with OEM, but they all have stress cracks. The plugs are usually wet after a few times of cranking, I even sprayed some starting fluid in there to see if it was possibly the fuel. I gapped the plugs at 31, they are new plugs along with the high tension cords. The ground was a little iffy so I ran a new ground with no luck on it. I am getting battery voltage at the three connections (12.56 volt). Is the resistance too much to get a good enough spark to ignite?

 

[figgie]

Yeah, all three coils are the same spec, I think they might be original, or at least someone replaced them with OEM, but they all have stress cracks. The plugs are usually wet after a few times of cranking, I even sprayed some starting fluid in there to see if it was possibly the fuel. I gapped the plugs at 31, they are new plugs along with the high tension cords. The ground was a little iffy so I ran a new ground with no luck on it. I am getting battery voltage at the three connections (12.56 volt). Is the resistance too much to get a good enough spark to ignite?

when in doubt, deffer to the TSRM.

TSRM states coils should read betweem .3-.5 ohms. Outside of that replace coils.

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

#2.

(this is for 89+ supra).

 

[vettedreams2001]

True, that's what I was leaning toward, just seeing if anyone else had same resistance and still running so I could track down another cause while the coils were being shipped. Thanks, I'll update when they get here...hopefully soon.

 

[jetjock]

You'd better keep looking....

 

[vettedreams2001]

What do you think other possibilities would be jetjock?

 

[supraguy31]

Well, If you decide that its the coils then I have 4 set here and would be glad to sell you a Perfect condition set since Im running COP

 

[TuRbOdReAmZ87]

i'm having the same problem with mine. I just tried starting it a few times and it wont. The plugs were bad, so i replaced them. Then tired again and it still didnt work, so i was guessing either a bad ignition coil or ignitor.

 

[vettedreams2001]

Here's an update, I got the coils in and tried them, .07 ohms? Even though it's a nice blue spark now, still no good. Cranked and nothing, checked fuel, yup, air...uh yeah, spark, yup. Leads me timing, I checked that the crank was at 0deg, cams are in the middle hole of the pulley and lines matched up to notches in the plates, cps with the drilled portion lined up with the groove on the shaft, huh-huh shaft...but still not even a thought about starting...just crank and crank and crank. I'm at my wits end, and now I definitely need it running so I can fix my truck, a spark plug hole was stripped due to aluminum heads and harder metal spark plugs and dropped a little bit into the cylinder and the piston tapped it a few times enough to break the coil hold down and cause a lot of blowby, so I tapped it and attempted to put a heli-coil in, but I got it down about half of the way before it started bending, so I stopped and have driven it like that since Monday, I need some more time to work on that. Need...more...beer!!

 

[vettedreams2001]

Ok we can put an end to this thread, coils were good, everything was good except exhaust cam, I put the cam gear lined up with the middle hole but didn't realize I put it on the left one on the cam, I knew it had to be simple and stupid. She started and ran, now I just have to figure out why it sounds like 4 monkeys in a 55 gal drum banging pots against rocks while rolling down a hill, lol. I think I know why and once again stupid of me but I can't verify the stupidocity yet.

 

[ForcedTorque]

Oh yea, put some oil in it before start up!

 

[vettedreams2001]

Oil??? You mean I have to drain the KY out of it, man the wife is gonna be pissed that I spent the money on filling it up with that, lol. I think I got the intake lifter shims on the exhaust side and visa versa.

 

[vettedreams2001]

Here's some more fun to put to this project, I pulled the pan and found a lot of shavings, and no rod bearing on no. 3, no I speced them out and replaced, now I just need to do some searches in the forums to see if anything can help with why it's not staying running now, before it ran and knocked, now it's starts and goes to 1500 rpm and drops down to 500 for a couple seconds and then dies. More fun.

 

[Kai]

Did you check the crank for scoring? The oil pump in case it was blocked?

 

[vettedreams2001]

I checked the big ends and the crank for spec and out of round as well as any scoring, took off the pump, disassembled, cleaned, checked the clearances on the gears. I am thinking that maybe when I jacked the motor up I maybe hit a connector somewhere, I've checked a lot of them, but haven't run into any that are noticeably damaged. I could see where if the clearances were off it would put a noticable amount of stress on the crank. Also if I tap the throttle a bit it dies immediately, that might be another indication on what's wrong.

 

[vettedreams2001]

Another update, I checked plugs to see if maybe I dented one while pushing the piston up (I know it's a non-interference motor, but you never know), they were all good, just cleaned them up. I then unplugged the IAC valve and then it started to waiver in rpm between 1-2k, so i proceeded to unplug the TPS, it leveled out at 1k, and I could rev it up. I warmed it up and checked other items since the head and bottom end work,I plugged in the IAC again without an issue, then drove it around my driveway but couldn't get it past 2.5k, I think that's due to intercooler lines being crap and the tps being unplugged, what do folks think?

 

[kotu100]

wow, wish i saw this thread a couple months ago, i had the EXACT same problem, friggin exhaust cam...

 

[CHRIS EICHMAN]

I have the same problem with my 89. weak coil spark when i test them. No spark (that I can see)while cranking. Not just one supra, but both that I have. They both ran before disasembly. One had a spun rod bearing and the other had a bhg. I read this thread but I dont understand about the problem that you had can you tell me more about the mistake because I cant figure out what i did wrong but it seems like I did the same thing to both cars.