Need help diagnoising Misfire.

[JDMMA70]

Dammit, so wiring from resistor to Injectors and ECU is good. Wiring for Injector 1 and 4 good. Spark Leads are in spec, Coils are in spec, Signal from the harness to coils good, Ignitor Good, Paper test showed the exhaust puffed the paper out when it missed. Hot start revealed a small puff of black smoke. So its not a valve, my guess now other than the fuel is obviously ignition, but on the ignition I have no idea what to check now. According to the TSRM the only thing left to try injector related is to try another ECU.


After that I guess its time to save for a leak down tester and a Compressor

 

[hvyman]

Might be able to rent a leak down tester from autozone or kragen and then just find a buddy with a compressor.

 

[JDMMA70]

I'm going to do a leak down test this weekend however I seems that my issue is getting worse it seems that on hot starts cylinder number 4 is flooding itself so now I'm kinda leaning more towards an ECU issue. Are 7M ECUs known to go bad

 

[7M-KDL]

Did you get it figured out?

 

[JDMMA70]

No I have not, new ecu changed nothing. Checked the timing again its at 10° BTDC advances to more than 12° BTDC when the jumper pins are pulled. Sitting at around 15° BTDC right now. The car starts flawlessly when cold but warm restarts the car struggles and I'm not sure what else to check. I don't think a bad o2 sensor can cause this issue. I'm about to give up and a leakdown test showed no issues with my head at all. I unplugged vacuum from the fpr during a hot restart to see if maybe my vsv was bad still same issue. I tried jumping B+ and FP and sometimes it seems to help sometimes it makes it worse. I've already given the engine so boost and it pulls great fantastic.

http://static.photobucket.com/playe...436/Cobra281s/20130821_205523_zpsdc9cf812.mp4

 

[7M-KDL]

Extended crank when hot could be due to fuel vaporization in the fuel rail. Don't know how hot it is when you have this issue but I occasionally have the same problem after a good drive in the summer here. You still have the misfire problem too? I didn't hear it in the video.

 

[JDMMA70]

Its only audible above 1200rpms http://static.photobucket.com/playe...lbums/v436/Cobra281s/MOV02735_zps15d255b2.mp4

And my hot starts are always like that always. Tbe video of me cranking was filmed in 85°F ambient temp

 

[7M-KDL]

Long crank time when hot still seems like vapor lock, try doing something to cool the fuel rail/lines down(keep them from getting as hot) and see if the problem continues. One old trick is to use a bunch of those wooden clothes pins and attach all along the fuel line. They are cheap and it is an easy way to test my vapor lock theory if you'd like. Could also be CPS related, but you've verified it's operation right?

 

[JDMMA70]

Its brand Toyota unit $$$ damn thing better work haha

 

[7M-KDL]

Did you ever try disconnecting the o2 sensor and running it?

 

[JDMMA70]

My o2 sensors hardwired in I'm working on getting connectors for them but my o2 sensor is black and sootydunno if its toast but I plan to test with a multi meter tonighr after work. Would that cause an issue though?

 

[jetjock]

...One old trick is to use a bunch of those wooden clothes pins and attach all along the fuel line. ...

Much easier on this car, after verifying rest pressure isn't at fault, is simply jump the fuel pump on. That'll purge vapor back to the tank and replace it with cooler fuel.

 

[7M-KDL]

It's possible, could explain why it's rich if it isn't reading properly.

 

[7M-KDL]

Much easier on this car, after verifying rest pressure isn't at fault, is simply jump the fuel pump on. That'll purge vapor back to the tank and replace it with cooler fuel.

Good call, yeh, that's easier I had thought about a drain back problem(what I assume you are referring to as rest) but I discarded that thought based on cold starts being fine. If pressure bleed off was a problem it would be a problem cold or hot right or are you referring to something different?

 

[JDMMA70]

Ill check fuel pressure once I get a gauge to test it. Also my jtube has been drilled out will that cause any issues? Used a drilled out tube for when i drop my Bosch fuel pump in. When I do jump the fuel pump am I to leave the pins in when I crank or remove them?

 

[3p141592654]

Secondary waveform analysis...

This thread needs to end....

 

[jetjock]

^ It would certainly tell the tale.

... If pressure bleed off was a problem it would be a problem cold or hot right or are you referring to something different?...

Loss of rest would cause far more problems hot than cold. After all vapor suppression is the main reason pressure is designed to be held.