cold starts

[domicubarican]

Hey guys, I swapped out my SOHC KA for a CA a two weeks ago and everytime I start it up it sounded like it was choking itself. If I touched the gas pedal it didn't want to rev, it would just choke up and die. When it warms up it runs fine. I found out the vacuum hose from the turbo to the wastegate was bad. I replaced that and well now it runs fine on cold starts but only under vacuum. When I start it up now and try to drive, it stalls out whenever it starts to build boost. Once it hits 0 vacuum it starts hesitating like it either can't breathe or doesn't want to build boost. It runs fine after its warmed up though. I don't really know what's going on, which is why I'm posting on here. Any thoughts?

[asher4857]

CAs are infamous for their cold start issues... you get used to it.

[Liquid_Neon]

yeah, even my 100% factory ca18de didnt like the cold mornings. it surged idle a lot, and i just sorta ignored it after 2+ years.

added: i re-read what you said... you car shouldnt sputter and die on boost. do u have a a/f gauge?

[domicubarican]

right now I don't, I plan on getting on when I get some more money. Right now the only gauge I have is boost. Yea on cold starts, when I try to start driving as soon as i give it gas it'll hesitate and wanna die. At first it sounds like its misfiring or not running on all cylinders, but once it warms up everything is fine even the boost is good.

When I changed out that vacuum line that connects from the nipple on the turbo to the wastegate everything went away. Started up fine on cold starts and everything. Next day it went back to the way it was...could it have anything to do the butterfly valve system not hooked up or anything?

[DALAZ_68]

so is that

CAs are infamous for their cold start issues... you get used to it.

why it takes 2 cranks for my car to strt early morning...it only happens early morning cold starts....takes 2 cranks for it to start...the first crank tun s on but just dies...

[rico05]

Mine did this exact thing. I have replaced:-FPR-MAF-IACV-Coils-Grounds-Rewired the harness 3x

The two things that finally fixed it were a new TPS and iridium plugs. Now, it starts fine, and boosts fine. It is still not as well as when it is 100% warm, but it is much better than the first 3 years of having my swap.

BTW, I am moving to DFW next weekend. We should meet up!

[Liquid_Neon]

right now I don't, I plan on getting on when I get some more money. Right now the only gauge I have is boost. Yea on cold starts, when I try to start driving as soon as i give it gas it'll hesitate and wanna die. At first it sounds like its misfiring or not running on all cylinders, but once it warms up everything is fine even the boost is good.

When I changed out that vacuum line that connects from the nipple on the turbo to the wastegate everything went away. Started up fine on cold starts and everything. Next day it went back to the way it was...could it have anything to do the butterfly valve system not hooked up or anything?

what is your vacuum reading at idle? If it is too low you might be sucking in to much air through a leak. that can cause the motor to run like shiet since there wouldn't be enough fuel for cold startup.most normal vacuum is between 15in and 20in I believe.

[Cams]

I was having awful cold start issues, having to turn the engine over for more than 30 seconds for it to start. What solved my issue was replacing the Engine (Water) Temp Sensor and cleaning the harness plug that goes to the sensor which had tons of green rust in it.

I havent been using the car much in the past months trying to solve a different issue, so I just start it every 5 days or so to keep the battery alive, and I haven't had a single issue with cold starts.

I'd say check for codes, I think 13 is the one for the temp sensor, and if so you know what your issue is.

[domicubarican]

at start up vacuum starts around 10-12 then as it warms up it goes to 16. Whenever i try to rev it up for a second it'll jump to 18-20 then back down 16 or below if it feels like it.

[domicubarican]

Mine did this exact thing. I have replaced:-FPR-MAF-IACV-Coils-Grounds-Rewired the harness 3x

The two things that finally fixed it were a new TPS and iridium plugs. Now, it starts fine, and boosts fine. It is still not as well as when it is 100% warm, but it is much better than the first 3 years of having my swap.

BTW, I am moving to DFW next weekend. We should meet up!

Yea that'd be great, nothing wrong with meeting new folk!

[ca18detgabby]

hesitation under boost sounds like a coil going..... from what I understand wrapping the wires with electrical tape helps, but I would check out the coils.

[rico05]

You always call coil Gabby, haha.

In my 4 years of having this motor, every time I have had a coil go (which is 4 times) it has been like a light switch. A cylinder will die. Now sometimes, it will work until hot, then die. But never a gradual loss of spark. Always a light switch.

Pulling that low of vacuum leads me to think you have a leak. Cold start, I pull 18inHg, at NOT (normal operating temp), I pull 20-21inHg.

[domicubarican]

yea thats what I was thinking. I plan on gettin some brand new vacuum lines when I get money next thursday.

I started it up today, from cold start it had 10-12 vacuum, when it warmed up to NOT it was at 16-18, and when I drive it goes to 20 and starts boosting fine.

[jakry001]

could it also be the ignitor?

i have the same issues. i have 4 sets of standard coil packs, and a set of brand new MSD coil packs, with all i have hesitation issues - especially on cold start. pressing the accelerator will make the engine splutter and want to die. once the car has warmed up, this problem goes away.

i missfire on cold starts all the time, and while driving, from time to time, it feels like im not getting enough power or something...

the ignition system is so simple, but this problem is so hard, and extremely annoying.

[RS12Turbo]

I had cold start issues...I replaced the dropping resistor with a brand new one from Nissan, and the cold start issues went completely away. It fires up and purrs perfectly now

[ca18detgabby]

You always call coil Gabby, haha.

In my 4 years of having this motor, every time I have had a coil go (which is 4 times) it has been like a light switch. A cylinder will die. Now sometimes, it will work until hot, then die. But never a gradual loss of spark. Always a light switch.

Pulling that low of vacuum leads me to think you have a leak. Cold start, I pull 18inHg, at NOT (normal operating temp), I pull 20-21inHg.

Ive had coils wear down on me and not burn as well, horribly annoying as it just doesnt quite feel the same. maybe Im just anal and noice it before it really is a problem. they also are significant under boost, but at idle not a horrible issue and create a surge affect. This is far different than a vac issue or fuel issue.

it also is the easiest and one of the more common issues I have experienced. Its even easier to diagnose that a vac leak.

ps it maybe that I have used all OEM secondhand coils but I have replaced 6-8 in the 2 years Ive had my motor in. Just seem to crap out on my when they feel like being an ***.

[rico05]

Wow. I have used BWD ones with no issues. $75 new at O'Reilly's.

And no, a bad ignitor will just die.

[domicubarican]

well its been a while but anyways update on the car....

Upper radiator hose busted and motor overheated a little, after me and a buddy got it fixed and running we checked everything and it ran like it used too. We discovered that one of my coils was bad, probably what was causing the cold start problems. I put in an order at the local autoparts store so it;ll be here by monday. Im hoping that will cure the cold start.

[domicubarican]

well cold start issues are still there but now another coil pack is bad I got the first one replaced now I have to wait for next week so I can buy another one. I might just get 3 more and replace them all to be done with. I'd buy one now but wit only 66 bucks to my name it ain't gonna happen lol