MarkC

cause my 88 Maxima to stall at idle at cold start-up? It will start but immediately die, whether I give it gas or not. This happens for 5-10 minutes, then it will start but idles rough at stops. It runs fine while driving.

Would it hurt to disconnect the air regulator until I can replace it?

Any other potential causes for this problem would be greatly appreciated.

I've read that cracked or worn vacuum lines could cause the same problems, but I don't know which ones to check.

It hasn't been this cold in Nashville in a long time.

dr.disc

Take the air regulator off and put it in the freezer. It should open when cold and close when warm. The CHTS (cylinder head temperature sensor)or the connector to it having corrosion or breaks in the wiring can be a problem. Makes the computer run things too rich. Part number 22630-01P00, and the harness is 24079-01P00. Get both.

MaxWgn

iTrader: (1)

Disconnecting the Air Regulator wouldn't provide any benefit, and it could be the cause.

Check with your local dealership...mine only cost $97 + tax from the Nissan house...or some aftermarker bosch & borg warner units can be found on-line for as little as $65. Do not buy a used one. Although they may test fine at that time, they could fail anytime...they seem to have about a 100k mile life expectancy rate...

MarkC

Did replacing your air regulator fix the problem of cold starting stalls?

MaxWgn

iTrader: (1)

Yes!

MarkC

Cool...Thanks!

max95q

iTrader: (10)

Yeah thats what its used for when starting up cold it lets additional air into the intake then when it warms up it closes.

Slider

I'm also looking into having my air regulator replaced but I'm not 100% sure it's really it, (hard to start when cold). Is there a way to test it? I read in a 240SX FAQ that if you hold the hose to the air regulator and the revs don't drop then it's broken. Is that true for our cars?

88ManY2K

Is the idle normal after it warms up? It should be
750-800 rpm.On a cold start up, it should fast idle
at 1200-1400 rpm or more, then slowly come back down
as the engine warms up.The air regulator would be the
first thing I would replace.It's easy to get to and you
can do it yourself. I also have a '88 Max with 219000 mi.
on it and I drive it every day.

Slider

The idle is normal when it's warm, on cold starts the idle is at approximately 650-700.

88ManY2K

It definitely sounds like your air regulator is
bad. I replaced my original one at 64000 in May'92.
The second one has been working fine ever since.

pkfinn

When our 87 Maxima began stalling on cold starts, I priced a new air regulator from the dealer. They wanted over $100 as I recall. Being too cheap to buy a new one, I went in search of a good used one at the junkyard. All of them were just like my old one - closed at room temperature. I bought a couple of them and cut one open to see how they worked. It seemed that most of them developed looseness where the bi-metallic assembly attaches to the housing (that's at the end where the electrical connector connects). The bi-metallic leaf seemed to work fine when heated, there was just so much slop in the thing that it couldn't overcome the shutter spring to open when it was cold. I came up with a repair that so far (over a year) has worked great. I drilled and tapped a 10-32 hole in the long round part of the housing near the base of the bi-metallic leaf. I put a screw with a jam nut in the new hole. I slowly screwed in the new adjustment screw while watching the shutter in the port. When the shutter was open just slightly, I locked the jam nut down against the housing. I reinstalled the valve and the fast idle was back! I experimented with the adjustment of the screw to get the cold fast idle where I wanted it, and when the engine warms up, the shutter closes and idle drops to normal. It was a cheap, relatively easy fix. If anyone is interested, I can sketch out the location where the hole should be drilled and you can try it for yourself.

Charles Bisel

Just out of curiosity, what would happen if you made the shutter stay open permanently? Would the engine run lean after it warmed up, or do you think the ECU would add more fuel to compensate for the extra air?

-C-

alllw86

[QUOTE]Originally posted by Charles Bisel
[B]Just out of curiosity, what would happen if you made the shutter stay open permanently? Would the engine run lean after it warmed up, or do you think the ECU would add more fuel to compensate for the extra air?

Good ??? Charles. I had that ? on my mind too since I also have a cold start idle problem. I also noticed that my car's exhaust smells like its burning too rich. Gas mileage has averaged 15-17 mpg, should be higher. When I fix this thing maybe my mpg will hopefully improve. I'll post the results.

pkfinn, that fix on the regulator sounds so easy. I been wanting to tear the regulator apart too, just to see what is making them go bad. If you could follow up on a procedure/diagrams maybe max88q will post it under FAQ.....that would be great....since this is a common problem with our Maxima.

Al

dr.disc

[QUOTE]Originally posted by alllw86
[B]Like I said: take it off and put it in the freezer to test it.

maximase86

iTrader: (24)

Hmmm, 15-16 mpg. What kind of driving is that? It is highway/freeway driving, constant stop and go, short in town driving? I ask this because that's pretty low, but then again if your doing stop and go driving, and short trip driving, it can cause that. If your not, I'd also check the ECU to see if its throwing some codes at you. I know my car is getting about 16mpg, but that's because 1, I let it idle a lot in the mornings to get heat going (15-20 minutes), 2 my average trip is about 4 miles. I get on the freeway maybe once a week. Also at times I tend to be a lead foot, so that attributes to my mileage. When I did drive it on freeways, and only freeways, I would get as much as 29-30mpg. So it is also really dependent on your driving style too.

S

pkfinn

Sorry for the delay, but I've been busy car shopping. The 87 that has the modified regulator died a couple of weeks ago. Dropped a valve or something and the timing belt tensioner stud broke. I'm not sure what happened first, but either way, the engine is trashed. We got a 1991 SE, and I've been busy cleaning it up, inspecting and getting it in shape for the teenage son to drive. Anyway, I dug around over the weekend and found the regulator I cut open. I'll try to get a friend to bring his digital camera in to work this week and take some pictures of it and also of the finished product on the engine (that no longer runs).

pkfinn

Here's a link to a page I just set up with the info on it. I've heard from a couple people who have tried it and it seemed to work for them as well. Leave me some feedback in the guestbook on the web page. Sorry it took so long to post it. I hope you will find it helpful.


2nd Generation Maxima Air Regulator Fix