It should start.... but won't.

[WillWorkFoBoost]

So I checked fuel pressure jumpering the fuelpump, and it has 50 psi and holds. but when I just crank the car it also has 50psi. Is this normal, im assuming because theres no vacc removing pressure from the fpr? if there was 15 lbs of vac it would bring fuel pressure at idle down to around 35.

 

[SRZMK3]

since thats eliminated now we need spark to ignite that fuel

and you are correct, my bad, XD its impossible to be 180 off if you go by the notches.

 

[WillWorkFoBoost]

Yea thing is it has spark though. since the beginning of this thread it has always had spark, fuel, and compression. only thing I can think of is maybe the spark looks a lil weak. Spark is at 10 deg btdc, Its got 12v to the coil connectors, I just threw another coil and some ngk wires on it, has spark, not great spark, but spark. no start.

 

[WillWorkFoBoost]

So I got my hands on a better timing light and on close inspection, the spark is a little intermittent. it will spark a couple times then miss a couple..... tried a different cps and was even worse. checked the connectors of the cps and its all fine, cleaned the magnetic pickups in the cps and still the same. any common areas the signal wires get chafed or tend to have issues besides the cps connector?

 

[WillWorkFoBoost]

So I looked through tsrm and the 4 wires from cps are g1, ne, g-, g2. Couldnt find which one is the signal. Im looking to find the signal, possibly run a new signal. tsrm didnt specify, just called them all cam position sensor. anyone know which is the signal?

 

[jetjock]

Not that it's related to your problem but except for G- they're all signals.

 

[SRZMK3]

so that means g1,ne and g2 are signals to each of the coil packs which there are 3 of?

 

[jetjock]

NE (Number of Engine revolutions) is the rpm signal. G1 and G2 are crank angle reference signals for cylinders 1 and 6. G- is ground. The three signals go into the ECU which in turn sends signals to the igniter telling it which pack to fire and when to fire it.

 

[Typhoon]

Pull codes. If crank signal weak etc it will set a code.

 

[WillWorkFoBoost]

There are no codes stored. Am I right in thinking that it would have to do with the signal somewhere either from cps to ecu or from ecu to igniter? I have 12v at each coil, ruling out a lack of power. plugs, wires, and igniter have all been switched with my other car, which are all known good parts.
Im gonna try my cps from running supra today, see what that does. I suppose it could be the pickups in the cps that I have on it now. At this point it seems like either the cps or signal wiring...

 

[WillWorkFoBoost]

So heres something weird, just like when I put my spare cps on and the spark was even more intermittent, I put on my known good one from my other supra...... no spark at all. messed with the wiring at cps connector, all connectors are tight, pins are in there,wiggled em around,checked over timing light, etc, no spark. it runs my other car perfectly. the one that was on the no start motor originally has the best spark, just misses like 2 out of 3... so leads me to think wiring.

 

[3p141592654]

If your CPS or wiring are bad to the ECU, you will get a code 12 after 2 or more seconds of cranking, and besides you won't get any spark at all. To double check, pull out the CPS, and with the ignition on spin the CPS shaft by hand. You should see a nice stream of sparks.

I know you replaced the ignitor, but check it has a good ground to the chassis, as that is the only ground it has from the factory?

Someone asked this a few times, but does it start on starter fluid?

 

[WillWorkFoBoost]

If your CPS or wiring are bad to the ECU, you will get a code 12 after 2 or more seconds of cranking, and besides you won't get any spark at all. To double check, pull out the CPS, and with the ignition on spin the CPS shaft by hand. You should see a nice stream of sparks.

I know you replaced the ignitor, but check it has a good ground to the chassis, as that is the only ground it has from the factory?

Someone asked this a few times, but does it start on starter fluid?

Nope, doesnt start with starter fluid, or the gas in the cylinders from injectors. has spark now with no misses, at 10 degrees btdc. has compression ranging from 135 to 150 across all cyls. still doesnt start.

When cranking and pumping the throttle Ive noticed after excessive cranking gas vapor/combustion gases come out through the afm housing... (no filter on)..... Im beginning to think itd be possible theres a rag or something in the exhaust manifold causing it to back up??? dunno why else vapor would be going out that way as opposed to out the exhaust. once again Il state also that the static timing is dead on, unless someone custom re-keyed crank or cam pulleys to fuck with me haha. Dunno I guess Im just clutching at straws at this point.

 

[jetjock]

Yeah, that must be it. I mean, you've checked all the obvious stuff. Why else would an engine with compression, spark, fuel, and correct timing not run? Has to be a rag...

 

[SRZMK3]

test fuel pressure.. dont deny it, must be completely positive of your fuel pressure to continue..

 

[WillWorkFoBoost]

Yeah, that must be it. I mean, you've checked all the obvious stuff. Why else would an engine with compression, spark, fuel, and correct timing not run? Has to be a rag...

Was really kinda joking....

 

[WillWorkFoBoost]

test fuel pressure.. dont deny it, must be completely positive of your fuel pressure to continue..

I already tested fuel pressure. I already posted up the fuel pressure.

 

[SupraPieces]

With fuel vapor coming out of the afm it might be possible an intake valve is stuck in the open position allowing vapors to travel backward through the intake

 

[SupraPieces]

eh scratch that you did a compression test

 

[IndigoMKII]

So you're positive you're getting a strong spark while the plug is IN the cylinder? I know you're going off of spark with a timing light but correct me if I'm wrong, the timing light goes off of the spark plug wire pulse, that doesn't mean the plug is firing a strong spark.