why isnt my sr being rad

[kevinzhou]

Well today I decided to work on the car since it has been sitting for a coupleofmonths. Thought it was a a bad injector so I replaced the tomei with brand new hks and new spark plugs ngk 8 heat range. New coilpacksand tested the maf and it was good.

The car was tuned with this same setup Turbo injectors everything.

The 4th cylinder will not fire at all. It gets spark should get fuel injectors are new dont think its the harness since I put the fourth plug on the thrid injector and it fired I'm so lost help me zilvia hopefully this isn't a noob question

[shanelach]

Try a new ecu. You could have a bad injector driver.

[s13panic]

I would agree with ecu. Def try that first. Swap a friends if possible.

[kevinzhou]

I don't a stock ecu would work since I have a 18g and 555cc

[shanelach]

It will be OK to just fire up real quick as a test.

[s13panic]

You can use a noid light at the injector harness and see if each individual injector is getting a pulse. You can also do this with test light or voltmeter. its just easier to see and read with an actual noid light.

[racepar1]

Did you do a compression check? Did you test for spark on that cylinder? DID you check for injector pulse on that cylinder? What does the spark plug look like on that cylinder compared to the rest? Does the cylinder smell like fuel?

It doesn't seem like you diagnosed the problem very much. Without actually diagnosing it you're just taking shots in the dark, and wasting money. If you don't know how to diagnose it, or you don't have the equipment, find someone in your area who DOES. Don't just replace random crap that MIGHT be causing the issue, like you already did...

The igniter is a MUCH more common failure than the ECU is as well.

[kevinzhou]

Compression wasn't check since I'm kinda scared too since when I got the motor it ran 200 across the board and I drove it 15 times Max after that including time on the dyno.

Spark was checked by have the plug in the coilpaxk and outside the motor. And it got spark.

The plugs were black but not too bad the forth one was wet not oil looked like fuel so I did the injectors and plugs but that was a month ago when I plugged them out.

New plugs are dry when I start it.

Didn't smell it yet since it was dry but its spitting a lot from the exhaust.

Idk about the ignator

[kevinzhou]

sorry on phone double post

[Corbic]

Did you do a compression check? Did you test for spark on that cylinder? DID you check for injector pulse on that cylinder? What does the spark plug look like on that cylinder compared to the rest? Does the cylinder smell like fuel?

It doesn't seem like you diagnosed the problem very much. Without actually diagnosing it you're just taking shots in the dark, and wasting money. If you don't know how to diagnose it, or you don't have the equipment, find someone in your area who DOES. Don't just replace random crap that MIGHT be causing the issue, like you already did...

The igniter is a MUCH more common failure than the ECU is as well.

This guy knows what's fucking up.

You don't need to buy anything to find the real problem. Stop "assuming" and start testing.

[kevinzhou]

guys i did test.
has spark tested it and it sparked like crazy
has fuel because i took the injector out and there was fuel in it
should not be the harness because i swapped over the plug that was supposed to be bad to injector 3 and it worked.
plugs seem normal just black
compression was not tested yet will do this weekend
something is not letting cylinder four fire up
it is spitting out alot of fuel though

ecu is fine running 55 code

[racepar1]

guys i did test.
has spark tested it and it sparked like crazy
has fuel because i took the injector out and there was fuel in it
should not be the harness because i swapped over the plug that was supposed to be bad to injector 3 and it worked.
plugs seem normal just black
compression was not tested yet will do this weekend
something is not letting cylinder four fire up
it is spitting out alot of fuel though

ecu is fine running 55 code

If you have spark, and you have fuel, the next logical step is to check compression. Spark + fuel + compression = BOOM! The only other option is for there to be too much fuel. I've seen a ford ECU short on the injector circuit so the the injector is always open, which is why I asked if the cylinder stank badly like fuel. Run the engine for a minute, check the plugs, compare. The #4 plug should look drastically different from the rest since it isn't firing. If it's SOAKED with fuel you might have an issue with the injector being always open, check for injector pulse with a noid light setup. Another option for too much fuel is a torn lower injector o-ring. If you popped the injectors in without lubricating the o-rings you could have torn one. I doubt that's the issue though since you had the same issue on another set of injectors.

[brndck]

has fuel because i took the injector out and there was fuel in it
it is spitting out alot of fuel though

ecu is fine running 55 code

this is not a valid test of your fuel injector.
You need to either buy or build a noid light to make sure the ecu is commanding that injector to fire.

[shobotan]

Checked rocker arms are still intact for cyl #4?

[kevinzhou]

did the compression test today and 125/130/120/90 in 40degrees :( i guess they tuned my car too lean or something because i never even got a chance to beat on it.

[shanelach]

So was the engine warm?

[kevinzhou]

no it was cold as ice. I just so sad right now i put so much time in this car

[fliprayzin240sx]

Did you open the Throttle Body when doing the test?

[shanelach]

Cold won't yield the best results

[beems240sx]

Did you open the Throttle Body when doing the test?

Agreed. Sounds like he didn't hold the throttle wide open while testing.

[rwtf]

Agreed. Sounds like he didn't hold the throttle wide open while testing.

This and plus 200psi on a sr20 is not right, 160 is standard factory .

[racepar1]

did the compression test today and 125/130/120/90 in 40degrees :( i guess they tuned my car too lean or something because i never even got a chance to beat on it.

You've got a compression issue, time to rip the engine apart...

/THREAD



So was the engine warm?

Did you open the Throttle Body when doing the test?

Cold won't yield the best results

Agreed. Sounds like he didn't hold the throttle wide open while testing.

This and plus 200psi on a sr20 is not right, 160 is standard factory .

EVERY SINGLE ONE OF YOU IS MISSING THE POINT! It doesn't matter if it's cold or hot. It doesn't matter if the throttle plate was being held open or not. What matters is the DRASTIC difference in the compression reading on cyl #4. As long as the compression was tested in the same manner on all cylinders then the compression should be about the same on all cylinders. The fact that one is drastically lower means that there is a mechanical problem on that cylinder.

[kevinzhou]

yea im still confused why the piston wont fire even with that low of compression..im still running on 3 cylinders...shouldnt it still fire with low compression

[Taniguchi_Is_#1]

maybe you messed up the valves on cyl 4? that would be low compression + no fire. iono.

[kevinzhou]

that is what i think im just gonna pull the head this week. I dont think it rings since it dosent smoke one bit.

[cbcm2435]

that is what i think im just gonna pull the head this week. I dont think it rings since it dosent smoke one bit.

it wouldnt smoke since its not firing

[kevinzhou]

it wouldnt smoke since its not firing

that would make sense:picardfp::newbie::bash::cry:

[Hoffman5982]

Why are you running an 8 heat range on your plugs?

[kevinzhou]

finally got my fat self outside and pulled the valve cover and saw the rocker arm chillin with my valves

[OrangeVirus1]

Cold to hot compression numbers may change, but it doesn't matter that much. If you have shitty cold numbers that are all over the place, it being hot aint going to help nothing.


I compression tested my RB20 in 10*F weather and got solid 130#'s on all 6 and I live 6500FT above sea level. and I did NOT WOT it either.

take into account the elevation shift on compression results I'm sitting in the low 160's at sea level cold.

If he was 140 on 1 and 90 on the other.... having the engine hot won't help nothing.

If his numbers are that far apart from eachother, A hot engine aint gonna fix that.


probly over-revved it if the Rocker arms fell out of place.