Uncontrolled Sudden Acceleration In I30!

[dr-rjp]

I just had a very, scary experience.

I was backing my 1998 I30 into a parking space. My foot was resting on the brake, when suddenly the car took off like someone had floored the accelerator pedal.

I had to stand on the brake pedal to keep the car from going any further, and slam the transmission into Park.

The engine was still racing when I turned off the ignition.

What's weird is that my foot was nowhere near the gas pedal.

It was resting on the brake pedal, and I was rolling backward into a parking space located on a sloped garage ramp, letting only gravity and engine idle propel me backwards.

When I got about 3 feet from the garage wall, that's when it felt like someone had stomped on the gas pedal. The car did hit the wall...although not very forcibly, thank God.

On the other hand, had the wall not been there, I would have probably kept going backwards a lot further than I did.

I'll keep you posted what the mechanics say. Right now, though, they cannot seem to duplicate it.

Maybe an exorcist is next??

[street_racer_00]

sounds like a sticky throttle mechanism to me...be careful.

[Nahkapohjola]

Originally Posted by dr-rjp

I just had a very, scary experience.
I was backing my 1998 I30 into a parking space. My foot was resting on the brake, when suddenly the car took off like someone had floored the accelerator pedal................
I had to stand on the brake pedal to keep the car from going any further, and slam the transmission into Park.
The engine was still racing when I turned off the ignition.
Maybe an exorcist is next??

When engine gets air, O2 signals ECU to increase injection. (Engine has to be warm.) One possibility: If throttle flap screws are lost, throttle will open. In this condition there is gas wobble &idle problems before this happens. More possibly wire connection to TB mechanism was lost.

...exorcist is next?? Devils power is rubbish, if u submit to the only Great Living God who is above all.

Throttle may jam, that is scary also. But that needs pushing pedal. One place which can cause this, is wire shield worn rubber parts that may get loose at TB. This should be checked.

One should always remember that sitting on 200 wild horses needs constant attention. Almost always turning ign key off, kills engine. There are stories when that does not work, and even brakes fail. Imagine whattodo in that situation? ...a separate killer switch would be nice to have...
Almost as scary is when u lose all power: steering, brakes while manouvering, that possibility may happen more often.

[dr-rjp]

Originally Posted by Nahkapohjola

When engine gets air, O2 signals ECU to increase injection. (Engine has to be warm.) One possibility: If throttle flap screws are lost, throttle will open. In this condition there is gas wobble &idle problems before this happens. More possibly wire connection to TB mechanism was lost.

The TB was the first thing I had checked. No worn parts. No rubber bits. No frayed ends. Nada. Clean as a whistle.

The only thing not working properly was the IACV.

The good news is that the problem could not be replicated...which is the worst news of all.

That means, dear friends, the car has to go!

[Nahkapohjola]

Originally Posted by dr-rjp

....
That means, dear friends, the car has to go!

That will make your enviro 0.000001% safer. Maybe. =Your demon will like the new ride.

I suggest you still check out all possible air leaks (there is a intermittent hole - sized on the power boost you experienced)

[dr-rjp]

Originally Posted by Nahkapohjola

That will make your enviro 0.000001% safer. Maybe. =Your demon will like the new ride.

I suggest you still check out all possible air leaks (there is a intermittent hole - sized on the power boost you experienced)

How would a hole cause the accelerator to go full throttle?

[dr-rjp]

I have since had three sets of mechanics check out my car -- one of them with the Infiniti dealership -- and none could find anything wrong with my car. I have also tried to duplicate the event, but without success.

Now, here's the problem. What if it happens again, and I am not so lucky? Some have said to me that it was just a fluke. Maybe, but I have absolutely no assurances that it would not happen again.

So, what would you do? If it were your I30, would you keep driving it, or would you get another car?

[JDM_ONLY]

yeah...FYI all INFINITI's 96 & up have steering power assist build in, while backing-up those sensors by the throttle/steering section might have malfunction. (If not) then don't hope for the worse!!

[Nahkapohjola]

Originally Posted by dr-rjp

How would a hole cause the accelerator to go full throttle?

To get quick acceleration, engine needs quickly large amount of air. If the accel is FULL, then the air amount is FULL. If accel is less than full, then air leak is less than full. (Only minor hosing or seal leaks are possible after TB.)

The only way I can figure this happening, is throttle itself, or smbdy/smtg affecting it:
- TB flaps loose.
- TB spring mech really warped by someone; springs get loose.
- driver pressing accel mech
- cruise control and/or wire shorted: cruise vacuum pump activates and cruise ctrl cable pulls throttle open.

As said, cars are ALWAYS dangerous. The more computers, the more %%%% chance they act weird. You wont see me leisure -standing in front-or-rear of an idling car (smbdy in)...

I dont think with new car is acheved nothing: repair AND !prepare this one. Change TB ? and disconnect cruise (or make new wire/switch to cruise pump so that it cannot come on; this in case no fault is found). Replace cruise control electronics box.

It is also fairly easy and cheap install a engine kill switch on dash, if you're still afraid of that. The killer switch has to be last in the command chain, cutting all to engine: this wire has to be well shielded not to become problem source itself. (Ignition ground, ECU power, Injector ground -cutoff?)

[dr-rjp]

Originally Posted by Nahkapohjola

- cruise control and/or wire shorted: cruise vacuum pump activates and cruise ctrl cable pulls throttle open.

You may be correct! I just finished reading this lengthy article written by an enginner about intermittant cruise control failure and sudden acceleration, and I have to agree with you that the CC has to be the culprit.

Click here for the article.

[Nahkapohjola]

Originally Posted by dr-rjp

You may be correct! I just finished reading this lengthy article written by an enginner about intermittant cruise control failure and sudden acceleration, and I have to agree with you that the CC has to be the culprit.

Click here for the article.

Some Maxima people complain of losing cruise ctrl alltogether. The medicine for them has been resoldering the cruise ctrl PCB printed circuit board. Afte PCB re-solder, all is well.

Nissan has used some poor (chinese jail?) workers in PCB soldering... Huh! That kind workmanShip may produce anythin. Replace that ctrl board.

The problem seems to be that the enable switch connects to that PCB logic - it is NOT a real cutoff switch. So if the logic goes haywire, nothing can stop it. Now I am already planning to change that! and connect the cruise enable switch so that cruise can in no circumstances be on acciDentally... yea, I'll read that.


BTW: do you remember if CRUISE CONTROL LIGHTS were on as it happened???

[dr-rjp]

Originally Posted by Nahkapohjola

BTW: do you remember if CRUISE CONTROL LIGHTS were on as it happened???

Don't really know. I can say, for sure, that I did not use the cruise control that day.

I did use it the day before without any problem.

However, there was something out of the ordinary that happened the day before. I let my girlfriend drive the car that day and she had a problem starting the car -- that is, she had the problem in sensing when the engine had started. She kept the ignition switch in the START position while she revved the engine. She did that twice. The third time she started the engine, she let go of the ignition switch immediately but she still revved the engine while in PARK.

Afterwards, the car drove very strangely. Cannot put my finger on what was wrong, but it just felt sluggish.

Any thoughts?

[Nahkapohjola]

Originally Posted by dr-rjp

.... it just felt sluggish.
Any thoughts?

The starter got its life's worth of speed...

This feeling is impossible to determine: it might be one of the zillion low voltage sensor connections playing with ECU - or the driver. Because of this, I am planning to buy the on board dyno, (maybe tazzo 85$) to be able to verify/separate my feelings from malfunction.

I have been trying to ask references, but seem that many do not have such... check: http://www.tazzo.com/Merchant2/merch...y_Code=AUTOACC