Misfire on cold start only

[Edyz7s]

Link to Video

https://www.dropbox.com/s/y6xt6xw91h...%20AM.mov?dl=0

My SR started doing this for a few weeks now. I stay in Cali and the mornings have been cold. This misfire I get only happens in the morning or when my car has been sitting for awhile.
I have checked:
Spark plugs - good shape

Coilpack - Still new, I installed Yaris coils with everything it needs to work. (No it didn't start doing after this)

Coolant Temp Sensor - Replaced couple months ago with autozone brand, not sure if this could be culprit

After it's been warmed up, my car would run great and not misfire.

[kyral]

that seems pretty normal
especially on high mileage equipment that cant electronically adjust everything on the fly

I can barely hear anything in your video

[Edyz7s]

Originally Posted by kyral

that seems pretty normal
especially on high mileage equipment that cant electronically adjust everything on the fly

I can barely hear anything in your video

Ive been told many cars misfire like that on cold days. But for me its new since its never done that before on cold starts. I have solid motor mounts so i feel it.

Sorry about the video, i recorded with my iphone, thought the sound would be good. Well basically in the video i just record my start up on a really cold morning. My SR takes awhile to warm up, ive done alot of cooling mods. But I capture my SR misfiring until it idles to operating temp

[kyral]

have you tried adjusting the CAS.
adjust it while its running, and turn it slowly either direction just a little bit and give it a minute and see how it affects the idle.
Obviously if it starts missing more turn it back the other direction. til you get a good idle.

Have an AFR gauge?

[Edyz7s]

Originally Posted by kyral

have you tried adjusting the CAS

Never messed with it since i've had my motor. You think it could have moved after for so long and caused this? What else would the CAS affect on the motor?

[oLemurs]

Originally Posted by Edyz7s

Never messed with it since i've had my motor. You think it could have moved after for so long and caused this? What else would the CAS affect on the motor?

before thinking about all of this stuff i would just take a timing light, clamp it around the black/white wire on the first coil pack and set the timing to 15 degrees advanced which is the 5th white line from the left.

[Kingtal0n]

whats wideband say


... you need a wideband

any order:
1. check timing
2. boost leak pressure test
3. wideband confirmation

[kyral]

Originally Posted by Edyz7s

Never messed with it since i've had my motor. You think it could have moved after for so long and caused this? What else would the CAS affect on the motor?

it affects ignition timing, it didnt move, youre just adjusting it to run better in the colder conditions, it would likely need to be adjusted back when the weather warms up

Originally Posted by oLemurs

before thinking about all of this stuff i would just take a timing light, clamp it around the black/white wire on the first coil pack and set the timing to 15 degrees advanced which is the 5th white line from the left.

adjusting a CAS takes significantly less time this seems quite excessive for a car that runs smoothly

Originally Posted by Kingtal0n

whats wideband say


... you need a wideband

any order:
1. check timing
2. boost leak pressure test
3. wideband confirmation

I second this

[Dirk Jan]

One doesn't just adjust a CAS for smoother idle when cold, wtf dude. Doing that will result in the car driving worse when warm (when it actually matters). Never a bad idea to check timing with a timing light though and setting it at factory settings as stated above.

[Edyz7s]

I agree with Dirk Jan, why would it be neccessary to mess around with the CAS just to have it running better for a certant weather codition? Guess i would just deal with the misfires for the mean time in this weather. Dont get me wrong, I will check it and see where is it at

Is what oLemurs said from the FSM? I have tried looking for this info and I had bad luck finding it. Just want a forsure conformation before doing so

Yes I need a wideband. Planning on getting that soon. I know i run rich but not horrible that i leave trails of smoke when gasing it hard

[kyral]

Originally Posted by Dirk Jan

One doesn't just adjust a CAS for smoother idle when cold, wtf dude. Doing that will result in the car driving worse when warm (when it actually matters). Never a bad idea to check timing with a timing light though and setting it at factory settings as stated above.

OP seems really anal about something quite trivial im just offering an idea
But you are right you can go from smooth idle to missing idle when warm.



[QUOTE=Edyz7s;6264332]I agree with Dirk Jan, why would it be necessary to mess around with the CAS just to have it running better for a certain weather condition? Guess i would just deal with the misfires for the mean time in this weather. Dont get me wrong, I will check it and see where is it at

dirk was talking about engine temperature not weather temperature. its very normal and common for an engine to want or need adjustments in different weather conditions, racecars get adjusted every race shortly before the race starts for optimum performance
Your daily driver likely does all this on the fly (as best as it can)
Dirk is saying dont tune your engine to run optimal cold (engine temp) cause it wont run optimal when its at operating temperature, Because I was suggesting to adjust timing slightly while cold to try and find a happy medium (personally I wouldnt touch it but OP asked)

[oLemurs]

Originally Posted by Edyz7s

I agree with Dirk Jan, why would it be neccessary to mess around with the CAS just to have it running better for a certant weather codition? Guess i would just deal with the misfires for the mean time in this weather. Dont get me wrong, I will check it and see where is it at

Is what oLemurs said from the FSM? I have tried looking for this info and I had bad luck finding it. Just want a forsure conformation before doing so

Yes I need a wideband. Planning on getting that soon. I know i run rich but not horrible that i leave trails of smoke when gasing it hard

how old are your spark plugs and what do you have them gapped to?

[Kingtal0n]

oh yeah do a tune up. Clean everything. Wash the engine. Cover the cas, maf, maybe the tps a little. Cover the coils. Everything else is fair game. If you clean everything spotless with towels and simple green, and do a tune up, well that is how you should be keeping it to begin with.

Look how clean I kept the sr area

abc always be cleaning

[Edyz7s]

@kyral you're the first person to help me out and suggest an idea and i thank you for that. I finally got myself a timing light today and plan on checking my timing tommorow.

@oLemurs I say they are about under a year old. I have the NGK BKR6E iridiums, gapped at .28 with a autozone gapper coin. Might have not been precise .28 but it had been running fine.

@Kingtal0n Dude, mad prop to yours. I've been neglecting my SR, cleaning wise, but do forsure try to maintain it running and keeping it healthy. I havent gotten a tune since i got the motor. I've done lots of bolt ons and minor upgrades that dont require tune but i do need a tune. I got myself a Jim Wold ECU thats just laying around, I plan on using that. Im just waiting to save up for a fuel managment upgrade so i can put it to good use

[oLemurs]

Originally Posted by Edyz7s

@kyral you're the first person to help me out and suggest an idea and i thank you for that. I finally got myself a timing light today and plan on checking my timing tommorow.

@oLemurs I say they are about under a year old. I have the NGK BKR6E iridiums, gapped at .28 with a autozone gapper coin. Might have not been precise .28 but it had been running fine.

@Kingtal0n Dude, mad prop to yours. I've been neglecting my SR, cleaning wise, but do forsure try to maintain it running and keeping it healthy. I havent gotten a tune since i got the motor. I've done lots of bolt ons and minor upgrades that dont require tune but i do need a tune. I got myself a Jim Wold ECU thats just laying around, I plan on using that. Im just waiting to save up for a fuel managment upgrade so i can put it to good use

i dont know exactly how you are running with the iridiums but my problem with those was that 1 they dont create good enough spark as copper but they do last longer, and 2 for me it was hard to gap the iridiums because the point would cut into the gapping coin that i had making it impossible to gap.

[Edyz7s]

I decided to get new spark plugs, (same ones for times sake) and the misfire significantly got reduced but is still there. Forsure its not as bad as before but then i checked the timing and was almost at 15 btdc. I was going to adjust the timing but going to timing mose my idle would be around 1k. I've read it's suppose to be around 850. I did not adjust it after all because i want to know if it will be okay to adjust if my idle is high in timing mode.

[Edyz7s]

I disconnected the maf today on a cold start. It would still misfire when the motor would warm up. So thats one thing that is also not causing the misfire.
Honestly thats the only time it really misfires, when getting to operating temperature.

[kyral]

Originally Posted by Edyz7s

I disconnected the maf today on a cold start. It would still misfire when the motor would warm up. So thats one thing that is also not causing the misfire.
Honestly thats the only time it really misfires, when getting to operating temperature.

its totally normal man

[Edyz7s]

I did some more reasearch with what I have, well its eiter misfire/detonation/pre-ignition. The knock sensor basically cures all of this so I have one coming in and hoping it fixes it. In the mean time i decided to do a compression test to test out if i had done any damage so far...
My results were:
Cold & Dry Test
Cylinder 1: 120 WET Test:130
Cylinder 2:119-120 WET test:144
Cylinder 3:128-130 WET test: 153
Cylinder 4:119-120 WET test: 35(Dont know if gauge was being faulty here)

Havent done a warm test but I started my 240 after 2 days of sitting and after many cracking, it started up amazing and no detonation/misfire/preignition

[oLemurs]

Originally Posted by Edyz7s

I did some more reasearch with what I have, well its eiter misfire/detonation/pre-ignition. The knock sensor basically cures all of this so I have one coming in and hoping it fixes it. In the mean time i decided to do a compression test to test out if i had done any damage so far...
My results were:
Cold & Dry Test
Cylinder 1: 120 WET Test:130
Cylinder 2:119-120 WET test:144
Cylinder 3:128-130 WET test: 153
Cylinder 4:119-120 WET test: 35(Dont know if gauge was being faulty here)

Havent done a warm test but I started my 240 after 2 days of sitting and after many cracking, it started up amazing and no detonation/misfire/preignition

do you know if the redtop SR has a knock sensor? im wondering because my wiring specialties harness didnt come with a wire to go to it.

[Edyz7s]

@oLemurs Yes the SR's have knock sensors. I have Wiring Specialties harness and they don't send the complete harness/wires you need for the motor. Luckly I got myself a really good condition SR and had all the wires i needed. Look around Google and see if you can find just that part of the harness, should be out there

[Dirk Jan]

The knock sensor plug is on the alternator/starter harness if I remember correctly. I know it is for CA18's.

[Edyz7s]

SOLVED!
It was my coilpack harness and none of what I tried doing/replacing. Turns out since I converted my harness to work with toyota coils, I did a bad job clamping the wires with the pins and it wasn't making a good connection. I got it fixed and now no more misfire in the morning/cold starts!