Okay. I have replaced the TPS sensor, the ECTS, run BG44K fuel cleaner through (actually it is still going), and I am still having problems starting this thing when it is cold. By cold, I mean sitting in the parking lot outside in 35 degree or lower temps. It takes an excessively long time to catch (oh yeah, the starter has been replaced, too), and once it does, I have to just goose the gas once to get it to hold. After that, the idle will creep up to about 1K RPMS and hold steady. After this, I am golden. It idles like a dream, and drives like a dream. The only reason this is an issue is because I am about to take this thing to Colorado where it may be below 0 outside, and I do not want any problems. Daniel Martin, if you read this, please give me a little more info on this Valve adjustment on the throttle body somewhere. If this is something I can adjust, please give me the specifics-I tried the A/C test and I do not get consistent results.

 

I have also changed the following:

Spark Plugs-NGK's
PCV Valve
Fuel Filter
Tranny Fluid (Auto)
Air Filter
Belts
Coolant
Battery

 

Did you test the TPS and find it defective, or did you just replace it blindly?
Did you test the ECTS and find it defective, or did you just replace it blindly?

 

TPS-$50
ECTS-$24.08

These 2 sensors were cheap enough that I just changed them blindly to save time.

 

The Idle Air Control Valve - Auxiliary Air Control adjusts the idle to compensate for fluctuating accessory loads such as the Air Conditioner compressor which switches on and off by itself. Your symptom is not a bad idle.

The IACV-AAC does play a role in starting, but it has the same function with warm starts and cold starts. This valve admits a small amount of air while the engine is cranking. That's why you are supposed to crank the engine with your foot off the gas pedal. If you imagine that the IACV-AAC is failing to perform this function you can easily mimic it by stepping on the gas pedal while cranking. Step down just a bit, just enough to crack open the throttle.

I understand your frustration. You've spent time and money to make the car behave properly and have not yet succeeded. This is an atypical problem, and possibly the combination of two problems which makes troubleshooting all the more difficult. Keep trying. After all, if you turn to the dealer he will keep trying... with the labor-hours "meter" running!

 

of water in the lines that freezes, cutting off some of the fuel? I know some people have problems with some gas stations because of water in the tanks. Just a shot in the dark, but where do you buy your gas?

 

I always buy gas from either Texaco or Exxon at 93 octane.

 

Are there any other items that control the vehicle idle that I have not hit on yet?

 

Do you have the IACV adjustment procedure? Is it something that can be done at home without special tools?

 

Here's the factory service manual component inspection procedure for the IACV-AAC.

1) Make this test with the ignition key OFF. Disconnect the IACV-AAC valve harness connector.

2) Looking into the valve connector with the latch at the top, you will see two rows with three terminal positions in each. They are numbered 1-3 (top row, right to left) and 4-6 (bottom row, right to left). Check resistance between the following terminals.
2 and 1.
2 and 3.
5 and 4.
5 and 6.
At a temperature of 68 F, the reading for all measurements should be approximately 30 ohms.

3) Reconnect the IACV-AAC valve harness connector.

4) Remove the idle air adjusting unit assembly (IACV-AAC valve is built-in) from engine. The IACV-AAC valve harness connector should remain connected.

5) Turn ignition switch ON and OFF, and verify that the IACV-AAC valve shaft smoothly moves forward and backward. If NG, replace the IACV-AAC valve.

 

[QUOTE]Originally posted by wczimmerman

Quote:

Do you have the IACV adjustment procedure? Is it something that can be done at home without special tools?

I thought this valve is adjustable, but can't find instructions for adjustment in the factory service manual.

My hands-on experience with these valves has been on a Stanza which had a simpler solenoid-actuated valve. I was able to rejuvenate the Stanza valve on two occasions by nothing more than careful cleaning with a dry cloth.

The Maxima valve is actuated by a stepper motor. This valve has not caused any trouble on my Maxima so I haven't had the occasion to remove it. (Knock on wood.)

 

My car runs like total crap when it's first started in cold weather. It'll hold a high idle around 1500rpm ok when it's first started, but when the idle tries to come down it starts missing or something. In order to get the car moving I have to feather the clutch at 1500rpm. Once it warms up it runs fine, idles smoothly at 600rpm and spins all of 1st gear.

I thought it was a tank of bad gas but I used drygas and have run at least 5 tanks of mobil 93/sunoco 94 through it since.

The check engine light came on soon after this started, but I'm tending to think it's because of something different: It came on at over 100mph, full bore in 4th gear after hitting 6500rpm in 1st-3rd :-) (Racing a S/C Grand Prix - I won)

Let me know what you find out. I need to sell my car (moving to europe) and I really, really hate paying someone to work on my car.

smokin96se
1996 Pearl White Maxima SE 5-Speed
FSTB, RT Cat, Custom Intake
Custom rubber chunks behind front wheel-wells

 

[QUOTE]Originally posted by wczimmerman

Quote:

Are there any other items that control the vehicle idle that I have not hit on yet?

There is an idle speed adjustment screw.
See Steve Cutchen's excellent MaxFAQ page at http://web2.airmail.net/scutchen/max_faq/
Click on SUBTOPICS just under Maintenance.
Click on Adjusting 4th Gen idle speed.

However, I doubt this is the answer to your problem.

 

[QUOTE]Originally posted by Daniel B. Martin

Quote:

Originally posted by wczimmerman

Quote:

Are there any other items that control the vehicle idle that I have not hit on yet?

There is an idle speed adjustment screw.
See Steve Cutchen's excellent MaxFAQ page at http://web2.airmail.net/scutchen/max_faq/
Click on SUBTOPICS just under Maintenance.
Click on Adjusting 4th Gen idle speed.

However, I doubt this is the answer to your problem.

"While banging his head against the wall, our hero asks,"

If you can think of anything else to try, please let me know...

 

2 more possibilities
1-Check the coolant temperature sensor, If the ECU doesn't know the engine is cold, it won't set the hi idle.
2-Check that the EGR valve moves freely when cold. If the EGR sticks open you'll have idle problems.

Both checks s/b in the manual.

 

Can you say....This problem sucks!!!

i have the same thing going on so im also looking for the answer. i had a post going for this topic last week so you might want to check that and see what's up. Drop me a line if you figure this one out.

Saber

 

When you step on the gas it catchs. Well if you tried the dry gas and fuel system cleaner stuff already, I would look into the fuel pump itself.

 

[QUOTE]Originally posted by Daniel B. Martin

Quote:

Originally posted by wczimmerman

Quote:

Are there any other items that control the vehicle idle that I have not hit on yet?

There is an idle speed adjustment screw.
See Steve Cutchen's excellent MaxFAQ page at http://web2.airmail.net/scutchen/max_faq/
Click on SUBTOPICS just under Maintenance.
Click on Adjusting 4th Gen idle speed.

However, I doubt this is the answer to your problem.

Actually, I think this got it. I did the procedure last night and tried starting it at lunch today (34 degrees outside)-started right up and idled at about 1400RPM, gradually going down as the temp increased.

Last night, after disconnecting the TPS, the Max wanted to idle at 400RPM. I suspect that when you start the car, before the ECU takes over the idle falls back on whatever is set by that screw, then the computer adjusts as needed. Regardless, it seems to run fine now. It's always the last thing you look at...