Can't figure this out

[s13hvv]

I have a ka24e that has had a misfire since I bought it three months ago. i've tried to figure it out. I've had lead technicians try and we are done racking our brains. You can stare at the engine and watch it misfire or listen to the exhaust. So this is what we have done:
-redone timing (it was off like advanced to hell off)
-checked fuel pressure (fine)
-ohmed fuel injectors (cylinder 4 was out of spec red 22.7 so I replaced it)
-replaced entire ignition system (cap, rotor, coil, wires (coil wire was torn), spark plugs))
-checked compression (143, 145, 143, 150)
-shit I even seafoamed hoping it would do something
-checked back pressure to see if my cat was plugged

idk man this engine is pissing me off
please help

[s13hvv]

bumb? anyone

[rcdad123]

when does it misfire? idle, under load, all the time?

[Slims]

video might help as well.

[rwtf]

That compression test is pretty low.

[s13hvv]

when does it misfire? idle, under load, all the time?

all the time

[s13hvv]

video might help as well.

its midnight but ill take one for you tomorrow if you'd like

[s13hvv]

That compression test is pretty low.

spec is 140-190 so yeah its on the low end my valve seals are probably leaking

[bad dog]

is it throwing any codes , also i would try and change out the ecm with a known good one , even buy one on ebay to have a spare , auto or manual transmission , ecm are different .

do you have a throttle position sensor or knock sensor , egr valve stuck open,
fuel filter , clean the maf sensor with autozone spray , i hope your alt is putting out about 14v.

check all the grounds you can find , check all vac lines for cracks.

my 240 is a 97 and no ext coil , you may want to change the capacitor on the coil .

you could read this link http://api.viglink.com/api/click?format=go&key=bf93db4b4e4f5c8e4137ddb2db3a3a1c&loc=http%3A%2F%2Fwww.240sxforums.com%2Fforums%2Fka 24de-ka24e%2F145139-ignition-timing-question.html&v=1&libid=1350777705764&out=http%3A%2F%2Fforums.nicoclub.com%2Fsetting-ka24e-timing-help-t543593.html&ref=http%3A%2F%2Fwww.google.com%2Furl%3Fsa%3Dt%26r ct%3Dj%26q%3D%26esrc%3Ds%26frm%3D1%26source%3Dweb% 26cd%3D2%26sqi%3D2%26ved%3D0CEQQrAIoADAB%26url%3Dh ttp%253A%252F%252Fwww.240sxforums.com%252Fforums%2 52Fka24de-ka24e%252F145139-ignition-timing-question.html%26ei%3DwzqDUJeaD870igLF_oHYCg%26usg% 3DAFQjCNFQOKEMgM0SP5rgYFtgHCZInZOwbA%26sig2%3D06hN YIkxOqPOeyb_ag3R4Q&title=Ignition%20timing%20question%20-%20Nissan%20240SX%20Forums&txt=Setting%20KA24E%20Timing%20*HELP*%20%3A%20240S X%20Technical%20Forum&jsonp=vglnk_jsonp_13507779588125

[s13hvv]

is it throwing any codes , also i would try and change out the ecm with a known good one , even buy one on ebay to have a spare , auto or manual transmission , ecm are different .

do you have a throttle position sensor or knock sensor , egr valve stuck open,
fuel filter , clean the maf sensor with autozone spray , i hope your alt is putting out about 14v.

check all the grounds you can find , check all vac lines for cracks.

my 240 is a 97 and no ext coil , you may want to change the capacitor on the coil .

you could read this link Setting KA24E Timing *HELP* : 240SX Technical Forum (http://api.viglink.com/api/click?format=go&key=bf93db4b4e4f5c8e4137ddb2db3a3a1c&loc=http%3A%2F%2Fwww.240sxforums.com%2Fforums%2Fka 24de-ka24e%2F145139-ignition-timing-question.html&v=1&libid=1350777705764&out=http%3A%2F%2Fforums.nicoclub.com%2Fsetting-ka24e-timing-help-t543593.html&ref=http%3A%2F%2Fwww.google.com%2Furl%3Fsa%3Dt%26r ct%3Dj%26q%3D%26esrc%3Ds%26frm%3D1%26source%3Dweb% 26cd%3D2%26sqi%3D2%26ved%3D0CEQQrAIoADAB%26url%3Dh ttp%253A%252F%252Fwww.240sxforums.com%252Fforums%2 52Fka24de-ka24e%252F145139-ignition-timing-question.html%26ei%3DwzqDUJeaD870igLF_oHYCg%26usg% 3DAFQjCNFQOKEMgM0SP5rgYFtgHCZInZOwbA%26sig2%3D06hN YIkxOqPOeyb_ag3R4Q&title=Ignition%20timing%20question%20-%20Nissan%20240SX%20Forums&txt=Setting%20KA24E%20Timing%20*HELP*%20%3A%20240S X%20Technical%20Forum&jsonp=vglnk_jsonp_13507779588125)

No codes are being thrown i will try the ecm after I have exhausted all other leads.
I will check the continuity, power, and ground on the knock sensor and the tps to make sure they are in spec.
the egr system is deleted and plugged.
Fuel filter is not clogged replaced it.
I have a bran new alternator replaced it when I first got the car because it was all fucked up. No vaccuum leaks. Had some when I first had the car but they were all repaired. I rechecked with my handy dandy can of brake cleaner.
I also cleaned the maf gave me a little bit better throttle response but still misfiring.
Also has stated before the entire igntition system has been replaced including the capacitor.

[Lunghz]

try and get a buddy or someone near you with a 240 to lend you their MAF, put it on and see if it helps, i seen a guy on here a month or two ago with a problem somewhat like yours and that ending up being the case (broken MAF). good luck tho!

[s13hvv]

try and get a buddy or someone near you with a 240 to lend you their MAF, put it on and see if it helps, i seen a guy on here a month or two ago with a problem somewhat like yours and that ending up being the case (broken MAF). good luck tho!

ill check that out thanks

[bad dog]

you say it is misfiring since you have had it , how many miles have you put on it , how much gas have you ran thru it . it could be bad gas ( water in the tank ) .

can you tell if the misfiring is thru exhaust or intake . did the tech put a scope on the spark plug wires and check the firing.

[s13hvv]

you say it is misfiring since you have had it , how many miles have you put on it , how much gas have you ran thru it . it could be bad gas ( water in the tank ) .

can you tell if the misfiring is thru exhaust or intake . did the tech put a scope on the spark plug wires and check the firing.

I've had it for three months probably driven it around 4500 miles I drive a lot and its misfiring through the exhaust every time i suddenly let off the throttle it backfires through the exhaust no blue flames though so I dont think it has a fast and furious kit

[s13hvv]

Also I believe the car is running rich because there is carbon build-up on my bumper just around the muffler exit. fuel pressure is in spec injectors in spec ignition in spec...

[bad dog]

are you sure the engine has the stock cams , if so you may have a cam a tooth or 2 off , thats why they had to set the timing so far advanced , if its firing thru the exhaust all the time it sounds like the timing ign/cams is retarded , there are many posts telling how to set up different cams in these engines to set the timing correcttly.


if you ever want to check the sensors here is some numbers to look for , but if you are not getting a service engine light ( does it work ) all sensors may be worling right. how many miles on the engine/car .

1 ) engine coolant temp sensor ==at 68 degrees 2,100-2900 ohms , 194 deg 236-260 ohms.

2) throttle position sensor ==closed approx 500 ohms , open approx 4,000 ohms.

3) knock sensor===500,000-620,000 ohms.

4) input air temp sensor===at 66 degrees 2,100-2,900 ohms.

5) crankshaft position sensor===at 66 degrees 166-203 ohms.

let me add that many sensors used in cars are what is called thermisters , meaning they have a negitive temp cofiencent in that as the temp goes up the resistance goes down and as temp goes down the themister resistance goes up.

that is what happens with the power chips you will find on ebay that replaces the intake air temp sensor , all they are is a resistor of about 4,000 ohms , this tells the ecm its about 50 degrees air coming in , the ecm then advances the ign timing , then the ecm tell the injecters to increase the duty cycle to give more fuel because of the advanced timing.

these resistors are worth about 25 cents.