View Full Version : 95 sc300 NA-t no spark. any advice before I set this thing on fire and make smores?
02-10-2011, 10:33 AM
So I bought a pearl white sc300 that already had a swap done to it. when I picked it up it took several tries to start but eventually would start and shortly after would die. I purchased the car because it was blowing oil thru the turbo (no oil restriction). As you can see from my username, I work at the turbo enthusiasts Disneyland (full-race) and had no reservations to swap turbos.. thats easy.. now begins the brain damage.. I get the car flatbedded to the shop and now it doesnt even start.. It cranks, and wants to start but no luck. I know there is fuel, 100% sure of that. Here is what Ive already done/revised..
0. confirmed fuel pulse with noid lights
1. optima battery
2. tested plug wires
3. new plugs (correctly gapped)
4. new distributor cap and rotor
5. confirmed distributor was aligned correctly (dots lined up on gear)
6. new igniter coil
7. re-wired mapecu wiring AND soldered (original owner twisted wires)
8. re-wired innovative o2 AND soldered
Im about 3 days away from getting 5 gallons of gasoline and matches..
There are 2 things that I havent changed yet and am unsure of..
1. igniter (not coil, actual igniter on drivers shock tower)
also, I see that there is a ground wire near the wiring loom where it enters the firewall. It is about 3 inches away from where it crosses inside.. It is not connected to anything and I was wondering whether that ground is supposed to go somewhere.
I know these type of posts are ridiculous since it is impossible to diagnose something from the other side of a computer, Im just wondering if Im missing anything.. or whether anyone else has had something similar.. Knowing what Ive already done, I wouldnt be surprised if its some type of short or ground wire missing..
Lastly, the member that guesses it correctly will get a discount to any products (except EFR) that we offer. :gapteeth:
02-11-2011, 12:15 AM
Follow the TSRM fors testing procedures and test to see if you have spark from the spark plug, check the IAC, since its a NA-T check the cam position sensor and crank position sensor at the distributor. Just my thoughts on it so far, good luck ^_^
02-11-2011, 09:53 AM
Thank you very much for your response! Its extremely appreciated. When you wrote to check the cam and crank position sensor at the distributor, do you mean checking the plug on the distributor to see if there is a reading? I went thru the ignition section on the tsrm and did the check on the plug, wires, distributor, and coil. There was a response in ohms that was in the working parameters that Toyota stated. I just have a feeling that its something absolutely minute such as a loose ground or something.
Let me know if I understood what you were suggesting. thanks so much! Ive got the marshmallows and graham crackers ready for when I set the car on fire..haha..
02-12-2011, 12:20 PM
Do you have B+ power at the injectors and ignition coil? If you are getting a regular injector pulse while cranking you most likely have a good crank signal. If you are getting battery power at the injectors and ignition coil I would check primary and secondary ignition resistance in the coil.
Does the tach move when cranking?
Are you getting B+ power at coil and injectors?
Does the check engine light illuminate when the key is in the "ON" position?
What year SC?
I am wondering if this is a Map Ecu problem.
02-12-2011, 03:37 PM
93 twinturbo, the tach doesnt move when its trying to crank, it goes dark. according to mapecu, it shows 200-4xx rpms when cranking but the tach on the dash doesnt show anything. Here is the new update as of now,
I changed out the igniter and now it actually HAS spark. It still doesnt start.. So now the only thing I havent swapped out is the ecu. The engine light is on so I know there is power going to the ECU.. Ive already tested the injectors with the noid light that plugs in the connector.. there is power going to the injectors. Its a 1995 sc300 and I emailed the guys at mapecu 2 weeks ago and have got no response from them.. not very helpful at all. So now, there is fuel, there is spark and there still isnt a running motor.... What the hell do I do now... the igniter coil is brand new and there is resistance there. the secondary coil is at 8.8 ohms and on the diag it states that its supposed to have anywhere from 9.0 to 15.5 So it is a little low but im still getting spark.. I had some techs over at the car today and they are lost aswell... they think its the tune now but even with the basemaps it should start, granted it would run like shit, it would still start..
I guess my next question is what would be the signs of a bad ecu?
02-12-2011, 04:06 PM
just some thought but worth the try
1. check the orange/white connector underneath the passenger side dash near the ecm make sure the connection is "locked" it's a double lock mechanism(sp?)
2. pull out the oil dipstick check for fuel smell, change it if you smell any. Chances are you flooded the engine with fuel when trying to start for a long time. injector size? what type(hi or lo imp)?
3. take off the cam cover check the timing
also more info on the setup...
02-12-2011, 04:37 PM
?? okay the orange and white connector, where is that at? this connector is something seperate of the ECU? Ill double check that connector when I get back to the car. As for the fuel flooding, that has happened.. Even when we clear the fuel from the cylinder, dry the plug out and re-install, it still doesnt start... I looked up the injectors and they are 66pph injectors. I dont know whether they are high or low impedance but regardless they are definitely working. I already checked the timing on the car and thats spot on. even when I try spraying starter fluid in the manifold it still wont.
02-12-2011, 04:40 PM
Here is what I found when searching for the fuel injector size. These are the ones I have on the car now. Should I be running some type of resistor box?
02-12-2011, 11:34 PM
Its possible that your plugs are fouled. I would disconnect the map ecu and just run it straight off the ecu. With High impedence injectors, you do not need a resistor pack.
Here is a very easy way to rule out the fuel/ ecu causing a crank and no start.
Pull the plugs and if they have raw fuel on them, switch them out for a new set.
Pull the fuel pump Fuse or disable the fuel pump
Spray brake clean or starter fluid into the throttlebody while cranking ( throttle butterfly closed).
If the car starts then you have a Fuel problem. You are probably getting too much fuel during cranking and fouling out the plugs after a few cranks.
02-13-2011, 07:21 AM
You said that you had a loose ground wire. You really need to connect that. Things need a proper ground to work, especially if it for the ECU or ignitor. Also make sure the ignitor is bolted down to the shock tower and the ECU is bolted to the floor securely.
02-13-2011, 10:01 AM
did you do a compression test? who did the swap and did it run before you bought it? possible blown motor/head? when you said you started it up for a short period did or if any smoke came up thru the exhaust if so what color? also check the efi fuse, change it out for a new one regardless of it looking not blown. I had a corroded fuse to my radio that looked ok, not blown and checked ok on a test light but i swapped out anyway and viola it works.
06-17-2011, 09:07 AM
Hope you get it figured out, but you really made me want some s'mores! Damn you!
10-13-2011, 08:15 AM
I had to use a lil brake clean to get my car running... I upgraded from 750-1000cc injectors went vvti COP and a few other things. The map in mine I know is extremely rich so yeah the brake clean got it running and then it ran by itself til I shut it off. Make sure you get flamable brake clean (some new stuff isnt flamable) and dont use starting fluid.
I would agree with your techs its in the tune.
Also after i got it running with a new set of plugs I swapped out a cam that I had to get machined... tried starting it again and nothing the plug in cylinder 1 looked fine but all the others were fouled out.
03-04-2013, 08:41 PM
Hope you get this figured out interested in what you did to fix it.
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