I am hoping Daniel B. Martin will bless this thread with some input! Here's the picture.

It's cold out and I start the car up and wait 30sec. and take off. When the car ****s into second (auto) the car is going about 20mph. As I climb to about 30mph (the speed limit) and hold it steady, you can feel the car surging and the rpm bounces with the movement of the car about 50rpm; almost like I was blipping the throttle to annoy my passengers.
As soon as I have driven about 1 mile, it's gone. Now, I have just done a tune up, checked the fuel pressure, changed the PCV valve, fuel filter and ran some fuel injector cleaner through it three times with no success.
What haven't I done? I haven't cleaned the throttle body. With nearly 66k on it, I have to wonder if that is it. At first I thought it was fuel pressure, but its not as its steady and within spec. Even it that was it, it wouldn't explain why it goes away in 1 mile. At this point, it's annoying more than anything. Any suggestions on what to use to clean the throttle body if that is actually it?

Thanks,
SHUMAX

 

95 max has a few common problems. Starter, and surging alternator. This is just what I think I remember. You say surge and thats what I think of. Its in a past post of mine to do with replacing my starter. Daniel B Martin is who you need to get.
Hope this gives you a direction.

 

top

 

Their are 2 possibilities that I would think of first. The "throttle position sensor" which could cause this and the next would be the "engine coolant temperature sensor". See if you are able to get a check engine code (even if you don,t have a light you still might have one their). It sounds as if it only happens during warm up and then dissappears. If you do a search I know that Dan explains in detail on how to test/check these 2 parts so good luck.

 

This surging symptom falls in the category of "driveability complaint". These are nasty problems because so many things can cause them. Sometimes it's a combination of minor defects, each of which is so slight that (by itself) you would never notice it.

Your surging occurs only during the first minute after a cold start. Please collect more data and post your observations here.

Start the engine when the outdoor temperature is low but don't drive away. Spend that first minute watching and listening. Is the idle smooth or rough? Is there any color or odor to the exhaust? This may give clues about an over-rich mixture or a misbehaving Exhaust Gas Recirculation valve.

Now jump in and drive as usual. Does the surging still occur? This will distinguish between a symptom which occurs during the first minute of engine operation versus the first minute of vehicle operation.

Verify that the Automatic Transmission Fluid level is correct.

Does your Maxima have any modifications? In particular, do you run with a non-standard air filter?

 

Daniel B. is back! Thanks!


Ok...here we go with input.


I jumped into the car this morning and watched the tach and it is smooth, no jumping as I am parked in the garage. The exhaust is clear, or maybe a bit white from condensation.

The transmission fluid level is fine and has been changed every 30k by the dealer. Although I am thinking of taking it to a place that has a 'sucker' machine like you talk about. Should I be afraid to ask them to put redline fluid in when I am there seeing as how the car has 66k on it? That's another topic, right?

Air filter? I am running a Place Racing CAI and have been for a year now. The problem just came about in the last two to three months and was never there last winter when I had it on. I also have a Stillen Exhaust and Bosch plugs. The car runs strong and VERY smooth after that first mile. Even during the first mile it NEVER stumbles or heistates; it just surges and nothing more. I thought it might be the plugs, but I swapped in some NGK's and it did the same thing...not the plugs, obviously!

I went out and measured the resistance of the Coolant Sensor and the TPS and they are fine...I am clueless. I am parting ways with it in about 7 months so I am not interested in dumping cash into something that simply annoys me. However, if it is a sign of something to come, I will fix it.

The tranny? I want some smoother shifts! I was thinking of using the 'sucker' machine and some redline. What type do I need and where can I get it the cheapest?

Thanks for your input Daniel....

SHUMAX

 

My own Maxima is a 5-speed and I have no experience with RedLine products.

I'm unfamiliar with Maxima modifications. Does your CAI use a non-standard air filter?

Good. These tests are easy to make and appropriate for the situation.


I'm struggling with the fact that this problem manifests itself only during the first one minute after a cold start. That would seem to eliminate a weak fuel pump. However, one minute might be enough to melt tiny ice crystals which are trapped in the fuel filter causing fuel starvation. You might try a can of DryGas or equivalent.

There is an Exhaust Gas Temperature Sensor which may be tested with an ohmmeter, similar to the Engine Coolant Temperature Sensor you already made. This test is shown in Chilton (page 4-11) and Haynes (page 6-20).

 

Ok....

The filter is of non-standard type....its conical in design.
I have not tried Dry Gas, but will do that! I might be a bit premature in saying it goes away in one min. It might last as long as 2min. but no longer at all. I know b/c it takes two min. to get to the highway and its always gone by then.


Any more thoughts???? I will check on the sensor you make mention of.

Thanks,
Curt Shumaker
SHUMAX

 

Remove that air filter and look inside the intake tract. If you see any kind of dust, the spotlight of suspicion falls on the filter. Non-standard air filters have been found to pass dirt and (even worse) to begin to disintegrate in use. If particles of filter media cling to the hot wire in the Mass Air Flow Sensor they interfere with its operation. The hot wire might burn them away during the first 1 - 2 minutes of engine operation.

As part of this intake tract examination you might as well go ahead and clean the throttle body. I don't think that is the root cause of your surging problem but it's easy enough to do.

 

What would you use to clean the throttle body? What type of cleaner? Just regular carb and choke cleaner...etc????

SHUMAX

 

Here are some facts:
- 95SE 5 spped
- Car surges for about the first 1-2 minutes
- 63K miles on it.
- Just recently (1 month ago), I changed the
PCV and cleaned the throttle body. Right
after that, I started getting the "surging"
effect in the AM, more obvious than ever before!
- Use K&N Air filter (CAI coming soon).
- Cleaned the TBody but did not clean the MAF sensor

My surging or bucking gets violent if I blip
the throttle just right and continue on with slight
pressure on the accelerator. I would imagine it
looks fairly violent from the outside of the car.

Not sure if this helps, but maybe we can draw
comparisons between my case and yours.

I will check the MAF and look for problems with that.
I was hoping on nailing this problem before the CAI
goes into the car. We'll see.

PeteMo
95SE

 

Mine doens't sounds as bad as yours. But then again, I haven't tried 'blipping' the throttle in the A.M. I am very getnle till it warms up...I don't rev above 2.5k at all. I am going to monitor it very strictly tomorrow and see what happens.

SHUMAX

 

I blip the throttle, but I NEVER let it get near 2.5K RPMs.
This happens around the 1800-2000 range. It never happened
last year, but this is the first year I noticed it.

 

What I meant was that the 1-2 shift MIGHT occur at 2.5k. Normally its about 2k. Once the 1-2 shift happens I get the surging. I have tried sppeding up to 40 when its in third and it doesn't surge as bad. but it is still there. That makes me think the tranny ISN'T suspect.

SHUMAX

 

 

You may clean the throttle body by removing the air duct and gently wiping the now-exposed throttle body interior with a lintless rag moistened with carburetor cleaner. Hold the throttle open with your left hand while you rub with your right hand.

 

I had a mass airflow sensor fail with similar symptoms on an old Pontiac. I had a hard time diagnosing the problem but it became obvious when tapping the area where the sensor is located while the engine was idling. This caused the engine to stumble and then rev up. However, this would not explain why you only experience the problem after start-up. Good luck solving your problem.

Evan