ca hesitate

[zil40]

my ca starts ruff and dies the first few times i start it.it sputers when you rev it up when cold. after running a while it runs better but still not right.it smells rich iv changed the maf, coolant temp sen, cam angel sen, spark plugs,nothing seems to work i have not driven it yet i dont want to mess it up any help would be great

[asher4857]

<insert generic "ca's have cold start problems do a search to see what you come up with" comment here>

[zil40]

most searches have led me to they all do that so im trying to figure it out iv tryed most things that i thought would help

[iliketocrash]

tried pullying codes?

[float_6969]

It's the little valve below the TB that has a large hose feeding into the manifold right behind the TB, on the head side of the plenum. IIRC, it's called an Air Regulator. I think you can get one off of the FWD SR20DE SE-R Sentra's.

[zil40]

what should that do if i replaced that valve

[kapower06]

check and re check for any vac or boost leaks along with checking for codes

[float_6969]

The purpose of that valve is to allow more air into the plunum during cold starts to increase the idle. If it doesn't work, then generally the motor doesn't turn fast enough to continue running.

[Logan76]

is that why when cold my CA Idles really high? like 2k. then after she heats up she runs great. If so I just learned something new. cool.

[float_6969]

Yup, it's supposed to idle up pretty high when it's cold. The CA is just cold blooded and I think Nissan knew it. The CA, when working propery, is a pretty fast cold idler. mine would usually idle closer to 1800-1900, but 2K isn't too far off.

[zil40]

the car warms up and idles fine, but once you put a load on it, it misfires really bad and backfires through the exhaust mostly but a little through the intake. if you can get the car to build boost it smooths out and revs fine. just when there is no manifold pressure the car will not run smoothly. it is backfires and misfires really bad until the moment it builds boost. after that it appears it runs fine. this is just with the car in the shop w/ no load. any suggestions why it runs terrible w/o positive manifold pressure and o.k. w/ boost?

[dattodude]

leaky injectors??? Get them cleaned. Otherwise after you turn the car off, the contents of the fuel rail can empty into the cylinders. Causing a start issue.

Reason it doesn't do it up high revs, is because the fuel required is so much, that the leak in the injector doesn't make "as big" a difference to the AF ratio.

..my 2 cents

[float_6969]

Are you SURE you don't have a vac/boost leak? This kinds sounds like that. Also, just to make sure, it only does this when it's cold? Once it warms up the car runs fine?

[Hillkill]

I'm having the same problem. When I start her and give it some gas the idle drops and sounds like it's about to die. Once she's a little warm she runs fine but every 30 seconds to 5 min she will sputter and backfire like she is going to die. Sometimes I give it gas and it misfires heavily. Gotta figure out the problem.

[zil40]

checked all of the charge pipes and couplers it doesn't appear to have a boost leak, unless the stock sr intercooler is leaking (cracked from shipping or something weird like that.) the car starts fine idles fine. but the moment you crack the throttle plate it goes to 5" to 0" of manifold vac. and bogs really bad and tries to die. as it gradually warms up it seems to get a little better w/ throttle input. it still never runs right when its warmed up. you can just slowly give it more throttle. once it boosts it runs and revs fine. but off boost it sputtters. when cold it is way worse that when it starts to warm up. one question, does the jdm and euro ca's have diff. maf sensors? our harness is 4 wire. our maf is "4 pin 3 wire" it has provisions for four wires but the "A" pin is factory molded blocked off. is the jdm ca supposed to have a 4 wire maf?

[kapower06]

sounds like you may have the wrong mafs . someone could have just wired in a sohc ka MAFS, they almost look identical.

[float_6969]

I'm having the same problem. When I start her and give it some gas the idle drops and sounds like it's about to die. Once she's a little warm she runs fine but every 30 seconds to 5 min she will sputter and backfire like she is going to die. Sometimes I give it gas and it misfires heavily. Gotta figure out the problem.

This sounds like some sort of ignition problem. Check out the ignitor.

checked all of the charge pipes and couplers it doesn't appear to have a boost leak, unless the stock sr intercooler is leaking (cracked from shipping or something weird like that.) the car starts fine idles fine. but the moment you crack the throttle plate it goes to 5" to 0" of manifold vac. and bogs really bad and tries to die. as it gradually warms up it seems to get a little better w/ throttle input. it still never runs right when its warmed up. you can just slowly give it more throttle. once it boosts it runs and revs fine. but off boost it sputtters. when cold it is way worse that when it starts to warm up. one question, does the jdm and euro ca's have diff. maf sensors? our harness is 4 wire. our maf is "4 pin 3 wire" it has provisions for four wires but the "A" pin is factory molded blocked off. is the jdm ca supposed to have a 4 wire maf?

First of all my car pulls about 38cm/Hg at idle. That equates to almost 15in/Hg. If you're only pulling 5in/Hg at idle, you've got a pretty good boost leak in the manifold somewhere. Possible sources are;TB Gasket (includes the plate on the back of the mani)The idle control crapBOTH intake manifold gasketsAny/All of the injector O-rings

I would also think that the car is idling pretty high.

As I said before, the fact that it runs fine under boost tells me it's a leak of some sort. The car runs lean under Vac and Rich under boost w/a MAFS system.

The lean condition could be causing your poor idle. It sounds to me like the problem is in the intake manifold somewhere

As far as the SOHC MAFS, it should work fine. The difference between the two is negligible.

[kapower06]

I agree. Only 5in/mg??? thats a decent sized leak, don't forget to check the butterfly system for leaks, the intake manifold, all vac. lines, also your boost gauge line, if its plastic it can crack. I pull right at 18-21in/mg at idle depending on temperature.

[float_6969]

Yea, I actually just got back from driving my car. When it's warmed up, it's well over 40cm/Hg, So that's closer to the 18-21 that kapower06 posted.

[MasterZenki]

in/Hg? cm/Hg? slap me a newb sticker on my face cuz im lost...

what is that and since my guess is its a measurement of vacuum..how do you figure that number?

[MasterZenki]

reason i ask is cuz im having sorta same problems...its prolly 30-40° here and i crank the engine and it turns fine but no fire...gas it a bit and it fires for like 2 secs and dies and i do this prolly 4 times before it starts running...its idling around 1500-1800...when i tried to rev it even a lil it dropped the idle below 800 so i let go of the gas and let it warm up and its good...my main point is does it really take that long to start this engine?

[float_6969]

in/Hg? cm/Hg? slap me a newb sticker on my face cuz im lost...

what is that and since my guess is its a measurement of vacuum..how do you figure that number?

There, you've been slapped!

Yes it is a measurement of vacuum. There is no such thing as negative pressure, since that's an oxymoron.

Vacuum is measured as the number of inches of movement in a column of some fluid. Mercury is generally used as the barometric pressure and temperature tend to effect it less than water.

Google is your friend;http://www.omega.com/literatur....html

[float_6969]

As was stated previously, the Air Regulator commonly fails on these motors and makes cold starts very hard. Used they can be had from an SR20DE from an SE-R. The Pulsar one doesn't work as it feeds directly into the intake manifold.

[zil40]

the 5" to 0 manifold vac. is when you just crack the throttle plate, not at idle. when the car is idleling 15"-16" while cold. when it is warmed up it is around 18". what i am wondering is why when i "crack" open the throttle plate. (about 1/8" open) it goes to 5" to 0 which would essentially be wide open. i will try to sub the air regulator. possibly that is stuck open or leaking and causing higher manifold pressure. or lower vac. however you want to look at it. when you slightly open your throttle, i'm sure your vac. gauge probibly only drops a couple of inches. as any other car i have driven does. but in this application it dives to 5" or less. i'll try your recommendations and let you know. thanks again.

[zil40]

as far as the air reg off the se-r what is it called because the part store has know idea about a air reg for that car

[kapower06]

timing? maybe....or a leak. just some suggestions since im really not sure.

[rico05]

http://www.nisspartswholesale.com/basket.php

If you want to buy at a parts house (Napa, Advance, O'Reilly, etc), I can get you a part interchange code. I will (if I remember, lol) look it up in the system at work tonite and see if a parts store can even get it (I work for Advance Auto).

Good luck. I bought a new IACV (Intake Air Control Valve in Nissan speak, "air regulator" in forum talk) and it didn't fix the same problem that you have. I have also replaced everything to no avail. Still have cold start woes. I am sending my injectors off for a cleaning/rebuild and see if that helps me any...

[sideways danny]

timing? maybe....or a leak. just some suggestions since im really not sure.

I'd say so

[zil40]

could you get the part number for the air reg

[zil40]

ok im still having this problem. i have metered everything back to the ecu. it all checks out fine. i was woundering could it be the ecu its self. it still stalls out when you crack the throttle. i have sens put the 24e maf on but dose not sem to run any better. if at all made it worse any body think it could be the ecu. i cant try another one because i have the only ca in my town. dose any body have one for sale let me know hopefully it will fix it thanx